import json
import os
from typing import Any, Callable, Dict, List, Optional

import citeproc_styles
from fatcat_openapi_client import EditgroupAnnotation
from fatcat_openapi_client.rest import ApiException, ApiValueError
from flask import (
    Response,
    abort,
    jsonify,
    make_response,
    redirect,
    render_template,
    request,
    send_from_directory,
    session,
    url_for,
)
from flask_login import login_required
from flask_wtf.csrf import CSRFError

from fatcat_tools.normal import (
    clean_arxiv_id,
    clean_doi,
    clean_isbn13,
    clean_issn,
    clean_orcid,
    clean_pmcid,
    clean_sha1,
    clean_sha256,
)
from fatcat_tools.transforms import citeproc_csl, release_to_csl
from fatcat_web import AnyResponse, Config, api, app, auth_api, mwoauth, priv_api
from fatcat_web.auth import (
    handle_ia_xauth,
    handle_logout,
    handle_token_login,
    handle_wmoauth,
    load_user,
)
from fatcat_web.cors import crossdomain
from fatcat_web.entity_helpers import (
    editgroup_get_diffs,
    generic_get_editgroup_entity,
    generic_get_entity,
    generic_get_entity_revision,
)
from fatcat_web.forms import SavePaperNowForm
from fatcat_web.graphics import (
    ia_coverage_histogram,
    preservation_by_date_histogram,
    preservation_by_volume_histogram,
    preservation_by_year_histogram,
)
from fatcat_web.kafka import kafka_pixy_produce
from fatcat_web.search import (
    FatcatSearchError,
    GenericQuery,
    ReleaseQuery,
    do_container_search,
    do_release_search,
    get_elastic_container_histogram_legacy,
    get_elastic_container_preservation_by_volume,
    get_elastic_container_random_releases,
    get_elastic_container_stats,
    get_elastic_entity_stats,
    get_elastic_preservation_by_date,
    get_elastic_preservation_by_type,
    get_elastic_preservation_by_year,
    get_elastic_search_coverage,
)

### Generic Entity Views ####################################################


@app.route("/container/<string(length=26):ident>/history", methods=["GET"])
def container_history(ident: str) -> AnyResponse:
    try:
        entity = api.get_container(ident)
        history = api.get_container_history(ident)
    except ApiException as ae:
        app.log.info(ae)
        abort(ae.status)
    return render_template(
        "entity_history.html", entity_type="container", entity=entity, history=history
    )


@app.route("/creator/<string(length=26):ident>/history", methods=["GET"])
def creator_history(ident: str) -> AnyResponse:
    try:
        entity = api.get_creator(ident)
        history = api.get_creator_history(ident)
    except ApiException as ae:
        abort(ae.status)
    return render_template(
        "entity_history.html", entity_type="creator", entity=entity, history=history
    )


@app.route("/file/<string(length=26):ident>/history", methods=["GET"])
def file_history(ident: str) -> AnyResponse:
    try:
        entity = api.get_file(ident)
        history = api.get_file_history(ident)
    except ApiException as ae:
        abort(ae.status)
    return render_template(
        "entity_history.html", entity_type="file", entity=entity, history=history
    )


@app.route("/fileset/<string(length=26):ident>/history", methods=["GET"])
def fileset_history(ident: str) -> AnyResponse:
    try:
        entity = api.get_fileset(ident)
        history = api.get_fileset_history(ident)
    except ApiException as ae:
        abort(ae.status)
    return render_template(
        "entity_history.html", entity_type="fileset", entity=entity, history=history
    )


@app.route("/webcapture/<string(length=26):ident>/history", methods=["GET"])
def webcapture_history(ident: str) -> AnyResponse:
    try:
        entity = api.get_webcapture(ident)
        history = api.get_webcapture_history(ident)
    except ApiException as ae:
        abort(ae.status)
    return render_template(
        "entity_history.html", entity_type="webcapture", entity=entity, history=history
    )


@app.route("/release/<string(length=26):ident>/history", methods=["GET"])
def release_history(ident: str) -> AnyResponse:
    try:
        entity = api.get_release(ident)
        history = api.get_release_history(ident)
    except ApiException as ae:
        abort(ae.status)
    return render_template(
        "entity_history.html", entity_type="release", entity=entity, history=history
    )


@app.route("/work/<string(length=26):ident>/history", methods=["GET"])
def work_history(ident: str) -> AnyResponse:
    try:
        entity = api.get_work(ident)
        history = api.get_work_history(ident)
    except ApiException as ae:
        abort(ae.status)
    return render_template(
        "entity_history.html", entity_type="work", entity=entity, history=history
    )


def generic_lookup_view(
    entity_type: str, lookup_template: str, extid_types: List[str], lookup_lambda: Callable
) -> AnyResponse:
    extid = None
    for key in extid_types:
        if request.args.get(key):
            extid = key
            extid_value = request.args.get(extid)
            if extid_value:
                extid_value = extid_value.strip()
                break
    if extid is None:
        return render_template(lookup_template)
    try:
        resp = lookup_lambda({extid: extid_value})
    except ValueError:
        return make_response(
            render_template(
                lookup_template, lookup_key=extid, lookup_value=extid_value, lookup_error=400
            ),
            400,
        )
    except ApiException as ae:
        if ae.status == 404 or ae.status == 400:
            return make_response(
                render_template(
                    lookup_template,
                    lookup_key=extid,
                    lookup_value=extid_value,
                    lookup_error=ae.status,
                ),
                ae.status,
            )
        else:
            app.log.info(ae)
            raise ae
    return redirect("/{}/{}".format(entity_type, resp.ident))


@app.route("/container/lookup", methods=["GET"])
def container_lookup() -> AnyResponse:
    return generic_lookup_view(
        "container",
        "container_lookup.html",
        ["issn", "issne", "issnp", "issnl", "wikidata_qid"],
        lambda p: api.lookup_container(**p),
    )


@app.route("/creator/lookup", methods=["GET"])
def creator_lookup() -> AnyResponse:
    return generic_lookup_view(
        "creator",
        "creator_lookup.html",
        ["orcid", "wikidata_qid"],
        lambda p: api.lookup_creator(**p),
    )


@app.route("/file/lookup", methods=["GET"])
def file_lookup() -> AnyResponse:
    return generic_lookup_view(
        "file", "file_lookup.html", ["md5", "sha1", "sha256"], lambda p: api.lookup_file(**p)
    )


@app.route("/fileset/lookup", methods=["GET"])
def fileset_lookup() -> AnyResponse:
    abort(404)


@app.route("/webcapture/lookup", methods=["GET"])
def webcapture_lookup() -> AnyResponse:
    abort(404)


@app.route("/release/lookup", methods=["GET"])
def release_lookup() -> AnyResponse:
    return generic_lookup_view(
        "release",
        "release_lookup.html",
        [
            "doi",
            "wikidata_qid",
            "pmid",
            "pmcid",
            "isbn13",
            "jstor",
            "arxiv",
            "core",
            "ark",
            "mag",
            "oai",
            "hdl",
        ],
        lambda p: api.lookup_release(**p),
    )


@app.route("/work/lookup", methods=["GET"])
def work_lookup() -> AnyResponse:
    abort(404)


### More Generic Entity Views ###############################################


def generic_entity_view(entity_type: str, ident: str, view_template: str) -> AnyResponse:
    entity = generic_get_entity(entity_type, ident)

    if entity.state == "redirect":
        return redirect("/{}/{}".format(entity_type, entity.redirect))
    elif entity.state == "deleted":
        return render_template("deleted_entity.html", entity_type=entity_type, entity=entity)

    metadata = entity.to_dict()
    metadata.pop("extra")
    entity._metadata = metadata

    if view_template == "container_view.html":
        entity._stats = get_elastic_container_stats(entity.ident, issnl=entity.issnl)
        entity._random_releases = get_elastic_container_random_releases(entity.ident)
    if view_template == "container_view_coverage.html":
        entity._stats = get_elastic_container_stats(entity.ident, issnl=entity.issnl)
        entity._type_preservation = get_elastic_preservation_by_type(
            ReleaseQuery(container_id=ident),
        )

    return render_template(
        view_template, entity_type=entity_type, entity=entity, editgroup_id=None
    )


def generic_entity_revision_view(
    entity_type: str, revision_id: str, view_template: str
) -> AnyResponse:
    entity = generic_get_entity_revision(entity_type, revision_id)

    metadata = entity.to_dict()
    metadata.pop("extra")
    entity._metadata = metadata

    return render_template(
        view_template, entity_type=entity_type, entity=entity, editgroup_id=None
    )


def generic_editgroup_entity_view(
    editgroup_id: Optional[str], entity_type: str, ident: str, view_template: str
) -> AnyResponse:
    try:
        editgroup = api.get_editgroup(editgroup_id)
    except ApiException as ae:
        abort(ae.status)

    entity, edit = generic_get_editgroup_entity(editgroup, entity_type, ident)

    if entity.revision is None or entity.state == "deleted":
        return render_template(
            "deleted_entity.html", entity=entity, entity_type=entity_type, editgroup=editgroup
        )

    metadata = entity.to_dict()
    metadata.pop("extra")
    entity._metadata = metadata

    return render_template(
        view_template, entity_type=entity_type, entity=entity, editgroup=editgroup
    )


@app.route("/container/<string(length=26):ident>", methods=["GET"])
def container_view(ident: str) -> AnyResponse:
    return generic_entity_view("container", ident, "container_view.html")


@app.route("/container_<string(length=26):ident>", methods=["GET"])
def container_underscore_view(ident: str) -> AnyResponse:
    return redirect("/container/{}".format(ident))


@app.route("/container/<string(length=26):ident>/coverage", methods=["GET"])
def container_view_coverage(ident: str) -> AnyResponse:
    # note: there is a special hack to add entity._type_preservation for this endpoint
    return generic_entity_view("container", ident, "container_view_coverage.html")


@app.route("/container/<string(length=26):ident>/metadata", methods=["GET"])
def container_view_metadata(ident: str) -> AnyResponse:
    return generic_entity_view("container", ident, "entity_view_metadata.html")


@app.route("/container/rev/<uuid:revision_id>", methods=["GET"])
def container_revision_view(revision_id: str) -> AnyResponse:
    return generic_entity_revision_view("container", str(revision_id), "container_view.html")


@app.route("/container/rev/<uuid:revision_id>/metadata", methods=["GET"])
def container_revision_view_metadata(revision_id: str) -> AnyResponse:
    return generic_entity_revision_view(
        "container", str(revision_id), "entity_view_metadata.html"
    )


@app.route("/editgroup/<editgroup_id>/container/<string(length=26):ident>", methods=["GET"])
def container_editgroup_view(editgroup_id: str, ident: str) -> AnyResponse:
    return generic_editgroup_entity_view(
        editgroup_id, "container", ident, "container_view.html"
    )


@app.route(
    "/editgroup/<editgroup_id>/container/<string(length=26):ident>/metadata", methods=["GET"]
)
def container_editgroup_view_metadata(editgroup_id: str, ident: str) -> AnyResponse:
    return generic_editgroup_entity_view(
        editgroup_id, "container", ident, "entity_view_metadata.html"
    )


@app.route("/creator/<string(length=26):ident>", methods=["GET"])
def creator_view(ident: str) -> AnyResponse:
    return generic_entity_view("creator", ident, "creator_view.html")


@app.route("/creator_<string(length=26):ident>", methods=["GET"])
def creator_underscore_view(ident: str) -> AnyResponse:
    return redirect("/creator/{}".format(ident))


@app.route("/creator/<string(length=26):ident>/metadata", methods=["GET"])
def creator_view_metadata(ident: str) -> AnyResponse:
    return generic_entity_view("creator", ident, "entity_view_metadata.html")


@app.route("/creator/rev/<uuid:revision_id>", methods=["GET"])
def creator_revision_view(revision_id: str) -> AnyResponse:
    return generic_entity_revision_view("creator", str(revision_id), "creator_view.html")


@app.route("/creator/rev/<uuid:revision_id>/metadata", methods=["GET"])
def creator_revision_view_metadata(revision_id: str) -> AnyResponse:
    return generic_entity_revision_view(
        "creator", str(revision_id), "entity_view_metadata.html"
    )


@app.route("/editgroup/<editgroup_id>/creator/<string(length=26):ident>", methods=["GET"])
def creator_editgroup_view(editgroup_id: str, ident: str) -> AnyResponse:
    return generic_editgroup_entity_view(editgroup_id, "creator", ident, "creator_view.html")


@app.route(
    "/editgroup/<editgroup_id>/creator/<string(length=26):ident>/metadata", methods=["GET"]
)
def creator_editgroup_view_metadata(editgroup_id: str, ident: str) -> AnyResponse:
    return generic_editgroup_entity_view(
        editgroup_id, "creator", ident, "entity_view_metadata.html"
    )


@app.route("/file/<string(length=26):ident>", methods=["GET"])
def file_view(ident: str) -> AnyResponse:
    return generic_entity_view("file", ident, "file_view.html")


@app.route("/file_<string(length=26):ident>", methods=["GET"])
def file_underscore_view(ident: str) -> AnyResponse:
    return redirect("/file/{}".format(ident))


@app.route("/file/<string(length=26):ident>/metadata", methods=["GET"])
def file_view_metadata(ident: str) -> AnyResponse:
    return generic_entity_view("file", ident, "entity_view_metadata.html")


@app.route("/file/rev/<uuid:revision_id>", methods=["GET"])
def file_revision_view(revision_id: str) -> AnyResponse:
    return generic_entity_revision_view("file", str(revision_id), "file_view.html")


@app.route("/file/rev/<uuid:revision_id>/metadata", methods=["GET"])
def file_revision_view_metadata(revision_id: str) -> AnyResponse:
    return generic_entity_revision_view("file", str(revision_id), "entity_view_metadata.html")


@app.route("/editgroup/<editgroup_id>/file/<string(length=26):ident>", methods=["GET"])
def file_editgroup_view(editgroup_id: str, ident: str) -> AnyResponse:
    return generic_editgroup_entity_view(editgroup_id, "file", ident, "file_view.html")


@app.route("/editgroup/<editgroup_id>/file/<string(length=26):ident>/metadata", methods=["GET"])
def file_editgroup_view_metadata(editgroup_id: str, ident: str) -> AnyResponse:
    return generic_editgroup_entity_view(
        editgroup_id, "file", ident, "entity_view_metadata.html"
    )


@app.route("/fileset/<string(length=26):ident>", methods=["GET"])
def fileset_view(ident: str) -> AnyResponse:
    return generic_entity_view("fileset", ident, "fileset_view.html")


@app.route("/fileset_<string(length=26):ident>", methods=["GET"])
def fileset_underscore_view(ident: str) -> AnyResponse:
    return redirect("/fileset/{}".format(ident))


@app.route("/fileset/<string(length=26):ident>/metadata", methods=["GET"])
def fileset_view_metadata(ident: str) -> AnyResponse:
    return generic_entity_view("fileset", ident, "entity_view_metadata.html")


@app.route("/fileset/rev/<uuid:revision_id>", methods=["GET"])
def fileset_revision_view(revision_id: str) -> AnyResponse:
    return generic_entity_revision_view("fileset", str(revision_id), "fileset_view.html")


@app.route("/fileset/rev/<uuid:revision_id>/metadata", methods=["GET"])
def fileset_revision_view_metadata(revision_id: str) -> AnyResponse:
    return generic_entity_revision_view(
        "fileset", str(revision_id), "entity_view_metadata.html"
    )


@app.route("/editgroup/<editgroup_id>/fileset/<string(length=26):ident>", methods=["GET"])
def fileset_editgroup_view(editgroup_id: str, ident: str) -> AnyResponse:
    return generic_editgroup_entity_view(editgroup_id, "fileset", ident, "fileset_view.html")


@app.route(
    "/editgroup/<editgroup_id>/fileset/<string(length=26):ident>/metadata", methods=["GET"]
)
def fileset_editgroup_view_metadata(editgroup_id: str, ident: str) -> AnyResponse:
    return generic_editgroup_entity_view(
        editgroup_id, "fileset", ident, "entity_view_metadata.html"
    )


@app.route("/webcapture/<string(length=26):ident>", methods=["GET"])
def webcapture_view(ident: str) -> AnyResponse:
    return generic_entity_view("webcapture", ident, "webcapture_view.html")


@app.route("/webcapture_<string(length=26):ident>", methods=["GET"])
def webcapture_underscore_view(ident: str) -> AnyResponse:
    return redirect("/webcapture/{}".format(ident))


@app.route("/webcapture/<string(length=26):ident>/metadata", methods=["GET"])
def webcapture_view_metadata(ident: str) -> AnyResponse:
    return generic_entity_view("webcapture", ident, "entity_view_metadata.html")


@app.route("/webcapture/rev/<uuid:revision_id>", methods=["GET"])
def webcapture_revision_view(revision_id: str) -> AnyResponse:
    return generic_entity_revision_view("webcapture", str(revision_id), "webcapture_view.html")


@app.route("/webcapture/rev/<uuid:revision_id>/metadata", methods=["GET"])
def webcapture_revision_view_metadata(revision_id: str) -> AnyResponse:
    return generic_entity_revision_view(
        "webcapture", str(revision_id), "entity_view_metadata.html"
    )


@app.route("/editgroup/<editgroup_id>/webcapture/<string(length=26):ident>", methods=["GET"])
def webcapture_editgroup_view(editgroup_id: str, ident: str) -> AnyResponse:
    return generic_editgroup_entity_view(
        editgroup_id, "webcapture", ident, "webcapture_view.html"
    )


@app.route(
    "/editgroup/<editgroup_id>/webcapture/<string(length=26):ident>/metadata", methods=["GET"]
)
def webcapture_editgroup_view_metadata(editgroup_id: str, ident: str) -> AnyResponse:
    return generic_editgroup_entity_view(
        editgroup_id, "webcapture", ident, "entity_view_metadata.html"
    )


@app.route("/release/<string(length=26):ident>", methods=["GET"])
def release_view(ident: str) -> AnyResponse:
    return generic_entity_view("release", ident, "release_view.html")


@app.route("/release_<string(length=26):ident>", methods=["GET"])
def release_underscore_view(ident: str) -> AnyResponse:
    return redirect("/release/{}".format(ident))


@app.route("/release/<string(length=26):ident>/contribs", methods=["GET"])
def release_view_contribs(ident: str) -> AnyResponse:
    return generic_entity_view("release", ident, "release_view_contribs.html")


@app.route("/release/<string(length=26):ident>/references", methods=["GET"])
def release_view_references(ident: str) -> AnyResponse:
    return generic_entity_view("release", ident, "release_view_references.html")


@app.route("/release/<string(length=26):ident>/metadata", methods=["GET"])
def release_view_metadata(ident: str) -> AnyResponse:
    return generic_entity_view("release", ident, "entity_view_metadata.html")


@app.route("/release/rev/<uuid:revision_id>", methods=["GET"])
def release_revision_view(revision_id: str) -> AnyResponse:
    return generic_entity_revision_view("release", str(revision_id), "release_view.html")


@app.route("/release/rev/<uuid:revision_id>/contribs", methods=["GET"])
def release_revision_view_contribs(revision_id: str) -> AnyResponse:
    return generic_entity_revision_view(
        "release", str(revision_id), "release_view_contribs.html"
    )


@app.route("/release/rev/<uuid:revision_id>/references", methods=["GET"])
def release_revision_view_references(revision_id: str) -> AnyResponse:
    return generic_entity_revision_view(
        "release", str(revision_id), "release_view_references.html"
    )


@app.route("/release/rev/<uuid:revision_id>/metadata", methods=["GET"])
def release_revision_view_metadata(revision_id: str) -> AnyResponse:
    return generic_entity_revision_view(
        "release", str(revision_id), "entity_view_metadata.html"
    )


@app.route("/editgroup/<editgroup_id>/release/<string(length=26):ident>", methods=["GET"])
def release_editgroup_view(editgroup_id: str, ident: str) -> AnyResponse:
    return generic_editgroup_entity_view(editgroup_id, "release", ident, "release_view.html")


@app.route(
    "/editgroup/<editgroup_id>/release/<string(length=26):ident>/contribs", methods=["GET"]
)
def release_editgroup_view_contribs(editgroup_id: str, ident: str) -> AnyResponse:
    return generic_editgroup_entity_view(
        editgroup_id, "release", ident, "release_view_contribs.html"
    )


@app.route(
    "/editgroup/<editgroup_id>/release/<string(length=26):ident>/references", methods=["GET"]
)
def release_editgroup_view_references(editgroup_id: str, ident: str) -> AnyResponse:
    return generic_editgroup_entity_view(
        editgroup_id, "release", ident, "release_view_references.html"
    )


@app.route(
    "/editgroup/<editgroup_id>/release/<string(length=26):ident>/metadata", methods=["GET"]
)
def release_editgroup_view_metadata(editgroup_id: str, ident: str) -> AnyResponse:
    return generic_editgroup_entity_view(
        editgroup_id, "release", ident, "entity_view_metadata.html"
    )


@app.route("/work/<string(length=26):ident>", methods=["GET"])
def work_view(ident: str) -> AnyResponse:
    return generic_entity_view("work", ident, "work_view.html")


@app.route("/work_<string(length=26):ident>", methods=["GET"])
def work_underscore_view(ident: str) -> AnyResponse:
    return redirect("/work/{}".format(ident))


@app.route("/work/<string(length=26):ident>/metadata", methods=["GET"])
def work_view_metadata(ident: str) -> AnyResponse:
    return generic_entity_view("work", ident, "entity_view_metadata.html")


@app.route("/work/rev/<uuid:revision_id>", methods=["GET"])
def work_revision_view(revision_id: str) -> AnyResponse:
    return generic_entity_revision_view("work", str(revision_id), "work_view.html")


@app.route("/work/rev/<uuid:revision_id>/metadata", methods=["GET"])
def work_revision_view_metadata(revision_id: str) -> AnyResponse:
    return generic_entity_revision_view("work", str(revision_id), "entity_view_metadata.html")


@app.route("/editgroup/<editgroup_id>/work/<string(length=26):ident>", methods=["GET"])
def work_editgroup_view(editgroup_id: str, ident: str) -> AnyResponse:
    return generic_editgroup_entity_view(editgroup_id, "work", ident, "work_view.html")


@app.route("/editgroup/<editgroup_id>/work/<string(length=26):ident>/metadata", methods=["GET"])
def work_editgroup_view_metadata(editgroup_id: str, ident: str) -> AnyResponse:
    return generic_editgroup_entity_view(
        editgroup_id, "work", ident, "entity_view_metadata.html"
    )


### Views ###################################################################


@app.route("/editgroup/<string(length=26):ident>", methods=["GET"])
def editgroup_view(ident: str) -> AnyResponse:
    try:
        eg = api.get_editgroup(str(ident))
        eg.editor = api.get_editor(eg.editor_id)
        eg.annotations = api.get_editgroup_annotations(eg.editgroup_id, expand="editors")
    except ApiException as ae:
        abort(ae.status)
    # TODO: idomatic check for login?
    auth_to = dict(
        submit=False,
        accept=False,
        edit=False,
        annotate=False,
    )
    if session.get("editor"):
        user = load_user(session["editor"]["editor_id"])
        auth_to["annotate"] = True
        if user.is_admin or user.editor_id == eg.editor_id:
            auth_to["submit"] = True
            auth_to["edit"] = True
        if user.is_admin:
            auth_to["accept"] = True
    return render_template("editgroup_view.html", editgroup=eg, auth_to=auth_to)


@app.route("/editgroup_<string(length=26):ident>", methods=["GET"])
def editgroup_underscore_view(ident: str) -> AnyResponse:
    return redirect(f"/editgroup/{ident}")


@app.route("/editgroup/<string(length=26):ident>/diff", methods=["GET"])
def editgroup_diff_view(ident: str) -> AnyResponse:
    try:
        eg = api.get_editgroup(str(ident))
        eg.editor = api.get_editor(eg.editor_id)
        eg.annotations = api.get_editgroup_annotations(eg.editgroup_id, expand="editors")
    except ApiException as ae:
        abort(ae.status)
    # TODO: idomatic check for login?
    auth_to = dict(
        submit=False,
        accept=False,
        edit=False,
        annotate=False,
    )
    if session.get("editor"):
        user = load_user(session["editor"]["editor_id"])
        auth_to["annotate"] = True
        if user.is_admin or user.editor_id == eg.editor_id:
            auth_to["submit"] = True
            auth_to["edit"] = True
        if user.is_admin:
            auth_to["accept"] = True
    diffs = editgroup_get_diffs(eg)
    return render_template(
        "editgroup_diff.html", editgroup=eg, auth_to=auth_to, editgroup_diffs=diffs
    )


@app.route("/editgroup/<string(length=26):ident>/annotation", methods=["POST"])
@login_required
def editgroup_create_annotation(ident: str) -> AnyResponse:
    if not app.testing:
        app.csrf.protect()
    comment_markdown = request.form.get("comment_markdown")
    if not comment_markdown:
        app.log.info("empty comment field")
        abort(400)
    # on behalf of user...
    user_api = auth_api(session["api_token"])
    try:
        eg = user_api.get_editgroup(str(ident))
        if eg.changelog_index:
            abort(400, "Editgroup already accepted")
        ega = EditgroupAnnotation(
            comment_markdown=comment_markdown,
            extra=None,
        )
        user_api.create_editgroup_annotation(eg.editgroup_id, ega)
    except ApiException as ae:
        app.log.info(ae)
        raise ae
    return redirect("/editgroup/{}".format(ident))


@app.route("/editgroup/<string(length=26):ident>/accept", methods=["POST"])
@login_required
def editgroup_accept(ident: str) -> AnyResponse:
    if not app.testing:
        app.csrf.protect()
    # on behalf of user...
    user_api = auth_api(session["api_token"])
    try:
        eg = user_api.get_editgroup(str(ident))
        if eg.changelog_index:
            abort(400, "Editgroup already accepted")
        user_api.accept_editgroup(str(ident))
    except ApiException as ae:
        app.log.info(ae)
        abort(ae.status)
    return redirect("/editgroup/{}".format(ident))


@app.route("/editgroup/<string(length=26):ident>/unsubmit", methods=["POST"])
@login_required
def editgroup_unsubmit(ident: str) -> AnyResponse:
    if not app.testing:
        app.csrf.protect()
    # on behalf of user...
    user_api = auth_api(session["api_token"])
    try:
        eg = user_api.get_editgroup(str(ident))
        if eg.changelog_index:
            abort(400, "Editgroup already accepted")
        user_api.update_editgroup(eg.editgroup_id, eg, submit=False)
    except ApiException as ae:
        app.log.info(ae)
        abort(ae.status)
    return redirect("/editgroup/{}".format(ident))


@app.route("/editgroup/<string(length=26):ident>/submit", methods=["POST"])
@login_required
def editgroup_submit(ident: str) -> AnyResponse:
    if not app.testing:
        app.csrf.protect()
    # on behalf of user...
    user_api = auth_api(session["api_token"])
    try:
        eg = user_api.get_editgroup(str(ident))
        if eg.changelog_index:
            abort(400, "Editgroup already accepted")
        user_api.update_editgroup(eg.editgroup_id, eg, submit=True)
    except ApiException as ae:
        app.log.info(ae)
        abort(ae.status)
    return redirect("/editgroup/{}".format(ident))


@app.route("/editor/<string(length=26):ident>", methods=["GET"])
def editor_view(ident: str) -> AnyResponse:
    try:
        entity = api.get_editor(ident)
    except ApiException as ae:
        abort(ae.status)
    return render_template("editor_view.html", editor=entity)


@app.route("/editor_<string(length=26):ident>", methods=["GET"])
def editor(ident: str) -> AnyResponse:
    return redirect(f"/editor/{ident}")


@app.route("/editor/<string(length=26):ident>/editgroups", methods=["GET"])
def editor_editgroups(ident: str) -> AnyResponse:
    try:
        editor = api.get_editor(ident)
        editgroups = api.get_editor_editgroups(ident, limit=50)
        # cheaper than API-side expand?
        for eg in editgroups:
            eg.editor = editor
    except ApiException as ae:
        abort(ae.status)
    return render_template("editor_editgroups.html", editor=editor, editgroups=editgroups)


@app.route("/editor/<string(length=26):ident>/annotations", methods=["GET"])
def editor_annotations(ident: str) -> AnyResponse:
    try:
        editor = api.get_editor(ident)
        annotations = api.get_editor_annotations(ident, limit=50)
    except ApiException as ae:
        abort(ae.status)
    return render_template("editor_annotations.html", editor=editor, annotations=annotations)


@app.route("/u/<string:username>", methods=["GET", "HEAD"])
def editor_username_redirect(username: str) -> AnyResponse:
    try:
        editor = api.lookup_editor(username=username)
    except ApiException as ae:
        abort(ae.status)
    return redirect(f"/editor/{editor.editor_id}")


@app.route("/changelog", methods=["GET"])
def changelog_view() -> AnyResponse:
    try:
        # limit = int(request.args.get('limit', 10))
        entries = api.get_changelog()  # TODO: expand="editors"
    except ApiException as ae:
        abort(ae.status)
    return render_template("changelog.html", entries=entries)


@app.route("/changelog/<int:index>", methods=["GET"])
def changelog_entry_view(index: int) -> AnyResponse:
    try:
        entry = api.get_changelog_entry(int(index))
        entry.editgroup.editor = api.get_editor(entry.editgroup.editor_id)
        entry.editgroup.annotations = api.get_editgroup_annotations(
            entry.editgroup_id, expand="editors"
        )
    except ApiException as ae:
        abort(ae.status)
    return render_template("changelog_view.html", entry=entry, editgroup=entry.editgroup)


@app.route("/reviewable", methods=["GET"])
def reviewable_view() -> AnyResponse:
    try:
        # limit = int(request.args.get('limit', 10))
        entries = api.get_editgroups_reviewable(expand="editors")
    except ApiException as ae:
        abort(ae.status)
    return render_template("editgroup_reviewable.html", entries=entries)


@app.route("/release/<string(length=26):ident>/save", methods=["GET", "POST"])
def release_save(ident: str) -> AnyResponse:

    form = SavePaperNowForm()

    # lookup release ident, ensure it exists
    try:
        release = api.get_release(ident)
    except ApiException as ae:
        abort(ae.status)

    if not Config.KAFKA_PIXY_ENDPOINT:
        return (
            render_template(
                "release_save.html", entity=release, form=form, spn_status="not-configured"
            ),
            501,
        )

    if form.is_submitted():
        if form.validate_on_submit():
            # got a valid spn request! try to send to kafka-pixy
            msg = form.to_ingest_request(release, ingest_request_source="savepapernow-web")
            try:
                kafka_pixy_produce(
                    Config.KAFKA_SAVEPAPERNOW_TOPIC,
                    json.dumps(msg, sort_keys=True),
                )
            except Exception:
                return (
                    render_template(
                        "release_save.html", entity=release, form=form, spn_status="kafka-error"
                    ),
                    500,
                )
            return (
                render_template(
                    "release_save.html", entity=release, form=form, spn_status="success"
                ),
                200,
            )
        elif form.errors:
            return render_template("release_save.html", entity=release, form=form), 400

    # form was not submitted; populate defaults
    if release.release_stage:
        form.release_stage.data = release.release_stage
    if release.ext_ids.doi:
        form.base_url.data = "https://doi.org/{}".format(release.ext_ids.doi)
    elif release.ext_ids.arxiv:
        form.base_url.data = "https://arxiv.org/pdf/{}.pdf".format(release.ext_ids.arxiv)
    elif release.ext_ids.pmcid:
        form.base_url.data = (
            "https://europepmc.org/backend/ptpmcrender.fcgi?accid={}&blobtype=pdf".format(
                release.ext_ids.pmcid
            )
        )
    elif release.ext_ids.hdl:
        form.base_url.data = "https://hdl.handle.net/{}".format(release.ext_ids.hdl)
    return render_template("release_save.html", entity=release, form=form), 200


### Search ##################################################################


@app.route("/search", methods=["GET", "POST"])
def generic_search() -> AnyResponse:
    if "q" not in request.args.keys():
        return redirect("/release/search")
    query = request.args["q"].strip()

    if len(query.split()) != 1:
        # multi-term? must be a real search
        return redirect(url_for("release_search", q=query, generic=1))

    if clean_doi(query):
        return redirect(url_for("release_lookup", doi=clean_doi(query)))
    if clean_pmcid(query):
        return redirect(url_for("release_lookup", pmcid=clean_pmcid(query)))
    if clean_sha1(query):
        return redirect(url_for("file_lookup", sha1=clean_sha1(query)))
    if clean_sha256(query):
        return redirect(url_for("file_lookup", sha256=clean_sha256(query)))
    if clean_issn(query):
        return redirect(url_for("container_lookup", issnl=clean_issn(query)))
    if clean_isbn13(query):
        return redirect(url_for("release_lookup", isbn13=clean_isbn13(query)))
    if clean_arxiv_id(query):
        return redirect(url_for("release_lookup", arxiv=clean_arxiv_id(query)))
    if clean_orcid(query):
        return redirect(url_for("creator_lookup", orcid=clean_orcid(query)))

    return redirect(url_for("release_search", q=query, generic=1))


@app.route("/release/search", methods=["GET", "POST"])
def release_search() -> AnyResponse:

    if "q" not in request.args.keys():
        return render_template("release_search.html", query=ReleaseQuery(), found=None)

    container_found = None
    if request.args.get("generic"):
        container_query = GenericQuery.from_args(request.args)
        container_query.limit = 1
        try:
            container_found = do_container_search(container_query)
        except Exception:
            pass

    query = ReleaseQuery.from_args(request.args)
    try:
        found = do_release_search(query)
    except FatcatSearchError as fse:
        return (
            render_template("release_search.html", query=query, es_error=fse),
            fse.status_code,
        )
    return render_template(
        "release_search.html", query=query, found=found, container_found=container_found
    )


@app.route("/container/search", methods=["GET", "POST"])
def container_search() -> AnyResponse:

    if "q" not in request.args.keys():
        return render_template("container_search.html", query=GenericQuery(), found=None)

    query = GenericQuery.from_args(request.args)
    try:
        found = do_container_search(query)
    except FatcatSearchError as fse:
        return (
            render_template("container_search.html", query=query, es_error=fse),
            fse.status_code,
        )
    return render_template("container_search.html", query=query, found=found)


@app.route("/coverage/search", methods=["GET", "POST"])
def coverage_search() -> AnyResponse:

    if "q" not in request.args.keys():
        return render_template(
            "coverage_search.html",
            query=ReleaseQuery(),
            coverage_stats=None,
            coverage_type_preservation=None,
            year_histogram_svg=None,
            date_histogram_svg=None,
        )

    query = ReleaseQuery.from_args(request.args)
    try:
        coverage_stats = get_elastic_search_coverage(query)
    except FatcatSearchError as fse:
        return (
            render_template(
                "coverage_search.html",
                query=query,
                coverage_stats=None,
                coverage_type_preservation=None,
                year_histogram_svg=None,
                date_histogram_svg=None,
                es_error=fse,
            ),
            fse.status_code,
        )
    year_histogram_svg = None
    date_histogram_svg = None
    coverage_type_preservation = None
    if coverage_stats["total"] > 1:
        coverage_type_preservation = get_elastic_preservation_by_type(query)
        if query.recent:
            date_histogram = get_elastic_preservation_by_date(query)
            date_histogram_svg = preservation_by_date_histogram(
                date_histogram,
                merge_shadows=Config.FATCAT_MERGE_SHADOW_PRESERVATION,
            ).render_data_uri()
        else:
            year_histogram = get_elastic_preservation_by_year(query)
            year_histogram_svg = preservation_by_year_histogram(
                year_histogram,
                merge_shadows=Config.FATCAT_MERGE_SHADOW_PRESERVATION,
            ).render_data_uri()
    return render_template(
        "coverage_search.html",
        query=query,
        coverage_stats=coverage_stats,
        coverage_type_preservation=coverage_type_preservation,
        year_histogram_svg=year_histogram_svg,
        date_histogram_svg=date_histogram_svg,
    )


@app.route("/container/<ident>/search", methods=["GET", "POST"])
def container_view_search(ident: str) -> AnyResponse:
    entity = generic_get_entity("container", ident)

    if entity.state == "redirect":
        return redirect(f"/container/{entity.redirect}")
    elif entity.state == "deleted":
        return render_template("deleted_entity.html", entity_type="container", entity=entity)

    if "q" not in request.args.keys():
        return render_template(
            "container_view_search.html",
            query=ReleaseQuery(),
            found=None,
            entity_type="container",
            entity=entity,
            editgroup_id=None,
        )

    query = ReleaseQuery.from_args(request.args)
    query.container_id = ident
    try:
        found = do_release_search(query)
    except FatcatSearchError as fse:
        return (
            render_template(
                "container_view_search.html",
                query=query,
                es_error=fse,
                entity_type="container",
                entity=entity,
                editgroup_id=None,
            ),
            fse.status_code,
        )

    return render_template(
        "container_view_search.html",
        query=query,
        found=found,
        entity_type="container",
        entity=entity,
        editgroup_id=None,
    )


def get_changelog_stats() -> Dict[str, Any]:
    stats = {}
    latest_changelog = api.get_changelog(limit=1)[0]
    stats["changelog"] = {
        "latest": {
            "index": latest_changelog.index,
            "timestamp": latest_changelog.timestamp.isoformat(),
        }
    }
    return stats


@app.route("/stats", methods=["GET"])
def stats_page() -> AnyResponse:
    try:
        stats = get_elastic_entity_stats()
        stats.update(get_changelog_stats())
    except Exception as ae:
        app.log.error(ae)
        abort(503)
    return render_template("stats.html", stats=stats)


### Pseudo-APIs #############################################################


@app.route("/stats.json", methods=["GET", "OPTIONS"])
@crossdomain(origin="*", headers=["access-control-allow-origin", "Content-Type"])
def stats_json() -> AnyResponse:
    try:
        stats = get_elastic_entity_stats()
        stats.update(get_changelog_stats())
    except Exception as ae:
        app.log.error(ae)
        abort(503)
    return jsonify(stats)


@app.route("/container/issnl/<issnl>/stats.json", methods=["GET", "OPTIONS"])
@crossdomain(origin="*", headers=["access-control-allow-origin", "Content-Type"])
def container_issnl_stats(issnl: str) -> AnyResponse:
    if not (len(issnl) == 9 and issnl[4] == "-"):
        abort(400, "Not a valid ISSN-L: {}".format(issnl))
    try:
        container = api.lookup_container(issnl=issnl)
    except ApiException as ae:
        raise ae
    try:
        stats = get_elastic_container_stats(container.ident, issnl=container.issnl)
    except (ValueError, IOError) as ae:
        app.log.error(ae)
        abort(503)
    return jsonify(stats)


@app.route("/container/<string(length=26):ident>/stats.json", methods=["GET", "OPTIONS"])
@crossdomain(origin="*", headers=["access-control-allow-origin", "Content-Type"])
def container_ident_stats(ident: str) -> AnyResponse:
    try:
        container = api.get_container(ident)
    except ApiException as ae:
        abort(ae.status)
    try:
        stats = get_elastic_container_stats(container.ident, issnl=container.issnl)
    except Exception as ae:
        app.log.error(ae)
        abort(503)
    return jsonify(stats)


@app.route(
    "/container/<string(length=26):ident>/ia_coverage_years.json", methods=["GET", "OPTIONS"]
)
@crossdomain(origin="*", headers=["access-control-allow-origin", "Content-Type"])
def container_ident_ia_coverage_years_json(ident: str) -> AnyResponse:
    try:
        container = api.get_container(ident)
    except ApiException as ae:
        abort(ae.status)
    try:
        histogram = get_elastic_container_histogram_legacy(container.ident)
    except Exception as ae:
        app.log.error(ae)
        abort(503)
    histogram_dicts = [dict(year=h[0], in_ia=h[1], count=h[2]) for h in histogram]
    return jsonify({"container_id": ident, "histogram": histogram_dicts})


@app.route(
    "/container/<string(length=26):ident>/ia_coverage_years.svg", methods=["GET", "OPTIONS"]
)
@crossdomain(origin="*", headers=["access-control-allow-origin", "Content-Type"])
def container_ident_ia_coverage_years_svg(ident: str) -> AnyResponse:
    try:
        container = api.get_container(ident)
    except ApiException as ae:
        abort(ae.status)
    try:
        histogram = get_elastic_container_histogram_legacy(container.ident)
    except Exception as ae:
        app.log.error(ae)
        abort(503)
    return ia_coverage_histogram(histogram).render_response()


@app.route(
    "/container/<string(length=26):ident>/preservation_by_year.json", methods=["GET", "OPTIONS"]
)
@crossdomain(origin="*", headers=["access-control-allow-origin", "Content-Type"])
def container_ident_preservation_by_year_json(ident: str) -> AnyResponse:
    try:
        container = api.get_container(ident)
    except ApiException as ae:
        abort(ae.status)
    query = ReleaseQuery(container_id=container.ident, exclude_stubs=True)
    try:
        histogram = get_elastic_preservation_by_year(query)
    except Exception as ae:
        app.log.error(ae)
        abort(503)
    return jsonify({"container_id": ident, "histogram": histogram})


@app.route(
    "/container/<string(length=26):ident>/preservation_by_year.svg", methods=["GET", "OPTIONS"]
)
@crossdomain(origin="*", headers=["access-control-allow-origin", "Content-Type"])
def container_ident_preservation_by_year_svg(ident: str) -> AnyResponse:
    try:
        container = api.get_container(ident)
    except ApiException as ae:
        abort(ae.status)
    query = ReleaseQuery(container_id=container.ident, exclude_stubs=True)
    try:
        histogram = get_elastic_preservation_by_year(query)
    except Exception as ae:
        app.log.error(ae)
        abort(503)
    return preservation_by_year_histogram(
        histogram,
        merge_shadows=Config.FATCAT_MERGE_SHADOW_PRESERVATION,
    ).render_response()


@app.route(
    "/container/<string(length=26):ident>/preservation_by_volume.json",
    methods=["GET", "OPTIONS"],
)
@crossdomain(origin="*", headers=["access-control-allow-origin", "Content-Type"])
def container_ident_preservation_by_volume_json(ident: str) -> AnyResponse:
    try:
        container = api.get_container(ident)
    except ApiException as ae:
        abort(ae.status)
    query = ReleaseQuery(container_id=container.ident, exclude_stubs=True)
    try:
        histogram = get_elastic_container_preservation_by_volume(query)
    except Exception as ae:
        app.log.error(ae)
        abort(503)
    return jsonify({"container_id": ident, "histogram": histogram})


@app.route(
    "/container/<string(length=26):ident>/preservation_by_volume.svg",
    methods=["GET", "OPTIONS"],
)
@crossdomain(origin="*", headers=["access-control-allow-origin", "Content-Type"])
def container_ident_preservation_by_volume_svg(ident: str) -> AnyResponse:
    try:
        container = api.get_container(ident)
    except ApiException as ae:
        abort(ae.status)
    query = ReleaseQuery(container_id=container.ident, exclude_stubs=True)
    try:
        histogram = get_elastic_container_preservation_by_volume(query)
    except Exception as ae:
        app.log.error(ae)
        abort(503)
    return preservation_by_volume_histogram(
        histogram,
        merge_shadows=Config.FATCAT_MERGE_SHADOW_PRESERVATION,
    ).render_response()


@app.route(
    "/container/<string(length=26):ident>/preservation_by_type.json",
    methods=["GET", "OPTIONS"],
)
@crossdomain(origin="*", headers=["access-control-allow-origin", "Content-Type"])
def container_ident_preservation_by_type_json(ident: str) -> AnyResponse:
    try:
        container = api.get_container(ident)
    except ApiException as ae:
        abort(ae.status)
    query = ReleaseQuery(container_id=container.ident)
    try:
        histogram = get_elastic_preservation_by_type(query)
    except Exception as ae:
        app.log.error(ae)
        abort(503)
    return jsonify({"container_id": ident, "histogram": histogram})


@app.route("/release/<string(length=26):ident>.bib", methods=["GET"])
def release_bibtex(ident: str) -> AnyResponse:
    try:
        entity = api.get_release(ident)
    except ApiException as ae:
        raise ae
    csl = release_to_csl(entity)
    bibtex = citeproc_csl(csl, "bibtex")
    return Response(bibtex, mimetype="text/plain")


@app.route("/release/<string(length=26):ident>/citeproc", methods=["GET"])
def release_citeproc(ident: str) -> AnyResponse:
    style = request.args.get("style", "harvard1")
    is_html_arg = request.args.get("html", "false")
    if is_html_arg and is_html_arg.lower() in ("yes", "1", "true", "y", "t"):
        is_html = True
    else:
        is_html = False

    try:
        entity = api.get_release(ident)
    except ApiException as ae:
        raise ae
    csl = release_to_csl(entity)
    try:
        cite = citeproc_csl(csl, style, is_html)
    except citeproc_styles.StyleNotFoundError as e:
        abort(400, e)
    if is_html:
        return Response(cite)
    elif style == "csl-json":
        return jsonify(json.loads(cite))
    else:
        return Response(cite, mimetype="text/plain")


@app.route("/health.json", methods=["GET", "OPTIONS"])
@crossdomain(origin="*", headers=["access-control-allow-origin", "Content-Type"])
def health_json() -> AnyResponse:
    return jsonify({"ok": True})


### Auth ####################################################################


@app.route("/auth/login")
def login() -> AnyResponse:
    # show the user a list of login options
    if not priv_api:
        app.log.warn(
            "This web interface not configured with credentials to actually allow login (other than via token)"
        )
    return render_template("auth_login.html")


@app.route("/auth/ia/login", methods=["GET", "POST"])
def ia_xauth_login() -> AnyResponse:
    if "email" in request.form and "password" in request.form:
        # if a login attempt...
        return handle_ia_xauth(request.form["email"], request.form["password"])
    # else show form
    return render_template("auth_ia_login.html")


@app.route("/auth/token_login", methods=["GET", "POST"])
def token_login() -> AnyResponse:
    # show the user a list of login options
    if "token" in request.args:
        return handle_token_login(request.args["token"])
    if "token" in request.form:
        return handle_token_login(request.form["token"])
    return render_template("auth_token_login.html")


@app.route("/auth/change_username", methods=["POST"])
@login_required
def change_username() -> AnyResponse:
    if not app.testing:
        app.csrf.protect()
    # show the user a list of login options
    if "username" not in request.form:
        abort(400)
    # on behalf of user...
    user_api = auth_api(session["api_token"])
    try:
        editor = user_api.get_editor(session["editor"]["editor_id"])
        editor.username = request.form["username"]
        editor = user_api.update_editor(editor.editor_id, editor)
    except ApiException as ae:
        app.log.info(ae)
        raise ae
    # update our session
    session["editor"] = editor.to_dict()
    load_user(editor.editor_id)
    return redirect("/auth/account")


@app.route("/auth/create_token", methods=["POST"])
@login_required
def create_auth_token() -> AnyResponse:
    if not app.testing:
        app.csrf.protect()

    duration_seconds = request.form.get("duration_seconds", None)
    if duration_seconds:
        try:
            duration_seconds_int = int(duration_seconds)
            assert duration_seconds_int >= 1
        except (ValueError, AssertionError):
            abort(400, "duration_seconds must be a positive non-zero integer")

    # check user's auth. api_token and editor_id are signed together in session
    # cookie, so if api_token is valid editor_id is assumed to match. If that
    # wasn't true, users could manipulate session cookies and create tokens for
    # any user
    user_api = auth_api(session["api_token"])
    resp = user_api.auth_check()
    assert resp.success

    # generate token using *superuser* privs
    editor_id = session["editor"]["editor_id"]
    try:
        resp = priv_api.create_auth_token(editor_id, duration_seconds=duration_seconds)
    except ApiException as ae:
        app.log.info(ae)
        raise ae
    return render_template("auth_token.html", auth_token=resp.token)


@app.route("/auth/logout")
def logout() -> AnyResponse:
    handle_logout()
    return render_template("auth_logout.html")


@app.route("/auth/account")
@login_required
def auth_account() -> AnyResponse:
    # auth check on account page
    user_api = auth_api(session["api_token"])
    resp = user_api.auth_check()
    assert resp.success
    editor = user_api.get_editor(session["editor"]["editor_id"])
    session["editor"] = editor.to_dict()
    load_user(editor.editor_id)
    return render_template("auth_account.html")


@app.route("/auth/wikipedia/auth")
def wp_oauth_rewrite() -> AnyResponse:
    """
    This is a dirty hack to rewrite '/auth/wikipedia/auth' to '/auth/wikipedia/oauth-callback'
    """
    return redirect(
        (b"/auth/wikipedia/oauth-callback?" + request.query_string).decode("utf-8"),
        307,
    )


@app.route("/auth/wikipedia/finish-login")
def wp_oauth_finish_login() -> AnyResponse:
    wp_username = mwoauth.get_current_user(cached=True)
    assert wp_username
    return handle_wmoauth(wp_username)


### Static Routes ###########################################################


@app.errorhandler(404)
def page_not_found(e: Exception) -> AnyResponse:
    return render_template("404.html"), 404


@app.errorhandler(401)
@app.errorhandler(403)
def page_not_authorized(e: Exception) -> AnyResponse:
    return render_template("403.html"), 403


@app.errorhandler(405)
def page_method_not_allowed(e: Exception) -> AnyResponse:
    return render_template("405.html"), 405


@app.errorhandler(400)
def page_bad_request(e: Exception) -> AnyResponse:
    return render_template("400.html", err=e), 400


@app.errorhandler(409)
def page_edit_conflict(e: Exception) -> AnyResponse:
    return render_template("409.html"), 409


@app.errorhandler(500)
def page_server_error(e: Exception) -> AnyResponse:
    app.log.error(e)
    return render_template("500.html"), 500


@app.errorhandler(502)
@app.errorhandler(503)
@app.errorhandler(504)
def page_server_down(e: Exception) -> AnyResponse:
    app.log.error(e)
    return render_template("503.html"), 503


@app.errorhandler(ApiException)
def page_fatcat_api_error(ae: ApiException) -> AnyResponse:
    """
    Generic error handler for fatcat API problems. With this error handler,
    don't need to explicitly catch API exceptions: they should get caught and
    routed correctly here.
    """
    if ae.status == 404:
        return page_not_found(ae)
    elif ae.status in [401, 403]:
        return page_not_authorized(ae)
    elif ae.status in [405]:
        return page_method_not_allowed(ae)
    elif ae.status in [409]:
        return page_edit_conflict(ae)
    try:
        json_body = json.loads(ae.body)
        ae.error_name = json_body.get("error")
        ae.message = json_body.get("message")
    except ValueError:
        pass
    return render_template("api_error.html", api_error=ae), ae.status


@app.errorhandler(ApiValueError)
def page_fatcat_api_value_error(ae: ApiValueError) -> AnyResponse:
    ae.status = 400
    ae.error_name = "ValueError"
    ae.message = str(ae)
    return render_template("api_error.html", api_error=ae), 400


@app.errorhandler(CSRFError)
def page_csrf_error(e: CSRFError) -> AnyResponse:
    return render_template("csrf_error.html", reason=e.description), 400


@app.route("/", methods=["GET"])
def page_home() -> AnyResponse:
    return render_template("home.html")


@app.route("/about", methods=["GET"])
def page_about() -> AnyResponse:
    return render_template("about.html")


@app.route("/rfc", methods=["GET"])
def page_rfc() -> AnyResponse:
    return render_template("rfc.html")


@app.route("/robots.txt", methods=["GET"])
def page_robots_txt() -> AnyResponse:
    if app.config["FATCAT_DOMAIN"] == "fatcat.wiki":
        robots_path = "robots.txt"
    else:
        robots_path = "robots.deny_all.txt"
    return send_from_directory(
        os.path.join(app.root_path, "static"), robots_path, mimetype="text/plain"
    )


@app.route("/sitemap.xml", methods=["GET"])
def page_sitemap_xml() -> AnyResponse:
    return send_from_directory(
        os.path.join(app.root_path, "static"), "sitemap.xml", mimetype="text/xml"
    )