"""
Helper routines for working with the fatcat citation graph, which is a separate
index of reference links between works in the main catalog.

See bulk citation and citation API proposals for design documentation.

TODO:

    surt_ify() helper (URL to SURT for queries)
    CSL enrichment method (using only elasticsearch mget)
    CSL enrichment for fatcat enrichment
    access transform
    microfilm access in access transform

    all_outbound_refs(...) -> List[BiblioRef]
    all_inbound_refs(...) -> List[BiblioRef]
        same as get_outbound_refs()/get_inbound_refs(), but does a scroll (return list or iterator?)
        (optional; maybe not public)
"""

import sys
import json
import datetime
import argparse
from enum import Enum
from typing import Optional, List, Any, Dict

from pydantic import BaseModel
import elasticsearch
from elasticsearch_dsl import Search, Q
from fatcat_openapi_client import ReleaseEntity

from fatcat_tools import public_api



class BiblioRef(BaseModel):
    """bibliographic reference"""
    # ("release", source_release_ident, ref_index)
    # ("wikipedia", source_wikipedia_article, ref_index)
    _key: Optional[str]
    update_ts: Optional[datetime.datetime]

    # metadata about source of reference
    source_release_ident: Optional[str]
    source_work_ident: Optional[str]
    # with lang prefix like "en:Superglue"
    source_wikipedia_article: Optional[str]
    # skipped: source_openlibrary_work
    # skipped: source_url_surt
    source_release_stage: Optional[str]
    source_year: Optional[int]

    # context of the reference itself
    # 1-indexed, not 0-indexed
    ref_index: Optional[int] # TODO: actually optional?
    # eg, "Lee86", "BIB23"
    ref_key: Optional[str]
    # eg, page number
    ref_locator: Optional[str]

    # target of reference (identifiers)
    target_release_ident: Optional[str]
    target_work_ident: Optional[str]
    target_openlibrary_work: Optional[str]
    target_url_surt: Optional[str]
    # would not be stored in elasticsearch, but would be auto-generated by all "get" methods from the SURT, so calling code does not need to do SURT transform
    target_url: Optional[str]
    # skipped: target_wikipedia_article

    # crossref, pubmed, grobid, etc
    match_provenance: str
    # strong, weak, etc
    match_status: Optional[str]
    # TODO: "match_strength"?
    # "doi", "isbn", "fuzzy title, author", etc
    # maybe "fuzzy-title-author"?
    match_reason: Optional[str]

    # only if no release_ident link/match
    target_unstructured: Optional[str]
    target_csl: Optional[Dict[str, Any]]

class AccessType(str, Enum):
    """describes type of access URL"""

    wayback = "wayback"
    ia_file = "ia_file"
    ia_microfilm = "ia_microfilm"
    repository = "repository"

class AccessOption(BaseModel):

    access_type: AccessType

    # note: for `target_url` refs, would do a CDX lookup and this URL would be
    # a valid/HTTP-200 web.archive.org capture URL
    access_url: str

    # application/pdf, text/html, etc
    # blank for landing pages
    mimetype: Optional[str]

    size_bytes: Optional[int]
    thumbnail_url: Optional[str]

class CslBiblioRef(BaseModel):
    # an "enriched" version of BiblioRef with metadata about the source or
    # target entity. would be "hydrated" via a lookup to, eg, the
    # `fatcat_release` elasticsearch index (fast mget fetch with a single
    # request), as opposed to fatcat API fetches
    ref: BiblioRef
    csl: Optional[Dict[str, Any]]
    access: List[AccessOption]

    class Config:
        arbitrary_types_allowed = True

class FatcatBiblioRef(BaseModel):
    # enriched version of BiblioRef with complete ReleaseEntity object as
    # fetched from the fatcat API. CSL-JSON metadata would be derived from
    # the full release entity.
    ref: BiblioRef
    release: Optional[ReleaseEntity]
    csl: Optional[Dict[str, Any]]
    access: List[AccessOption]

    class Config:
        arbitrary_types_allowed = True

class RefHits(BaseModel):
    count_returned: int
    count_total: int
    offset: int
    limit: int
    query_time_ms: int
    query_wall_time_ms: int
    result_refs: List[BiblioRef]

def _execute_ref_query(search: Any, limit: int, offset: Optional[int] = None) -> List[BiblioRef]:

    limit = min((int(limit or 15), 200))
    if not offset or offset < 0:
        offset = 0

    search = search.params(track_total_hits=True)
    search = search[offset : (offset + limit)]

    query_start = datetime.datetime.now()
    try:
        resp = search.execute()
    except elasticsearch.exceptions.RequestError as e_raw:
        # this is a "user" error
        e: Any = e_raw
        #logging.warn("elasticsearch 400: " + str(e.info))
        if e.info.get("error", {}).get("root_cause", {}):
            raise ValueError(str(e.info["error"]["root_cause"][0].get("reason"))) from e
        else:
            raise ValueError(str(e.info)) from e
    except elasticsearch.exceptions.TransportError as e:
        # all other errors
        #logging.warn(f"elasticsearch non-200 status code: {e.info}")
        raise IOError(str(e.info)) from e
    query_delta = datetime.datetime.now() - query_start

    result_refs = []
    for h in resp.hits:
        # might be a list because of consolidation
        if isinstance(h._d_.get('source_work_ident'), list):
            h._d_['source_work_ident'] = h._d_['source_work_ident'][0]
        result_refs.append(BiblioRef.parse_obj(h._d_))

    return RefHits(
        count_returned=len(result_refs),
        # ES 7.x style "total"
        count_total=resp.hits.total.value,
        offset=offset,
        limit=limit,
        query_time_ms=int(resp.took),
        query_wall_time_ms=int(query_delta.total_seconds() * 1000),
        result_refs=result_refs,
    )


def get_outbound_refs(
    es_client: Any,
    release_ident: Optional[str] = None,
    work_ident: Optional[str] = None,
    wikipedia_article: Optional[str] = None,
    limit: int = 100,
    offset: Optional[int] = None,
    es_index: str = "fatcat_ref",
) -> List[BiblioRef]:

    search = Search(using=es_client, index=es_index)

    if release_ident:
        search = search.filter("term", source_release_ident=release_ident)
    elif work_ident:
        search = search.filter("term", source_work_ident=work_ident)
    elif wikipedia_article:
        search = search.filter("term", source_wikipedia_article=wikipedia_article)
    else:
        raise ValueError("require a lookup key")

    # TODO: schema doesn't support either of these currently
    #search = search.sort("ref_index")
    #search = search.sort("ref_key")

    # re-sort by index
    hits = _execute_ref_query(search, limit=limit, offset=offset)
    hits.result_refs = sorted(hits.result_refs, key=lambda r: r.ref_index or 0)
    return hits

def get_inbound_refs(
    es_client: Any,
    release_ident: Optional[str] = None,
    work_ident: Optional[str] = None,
    openlibrary_work: Optional[str] = None,
    url_surt: Optional[str] = None,
    url: Optional[str] = None,
    consolidate_works: bool = True,
    filter_stage: List[str] = [],
    filter_type: List[str] = [],
    limit: int = 25,
    offset: Optional[int] = None,
    es_index: str = "fatcat_ref",
) -> List[BiblioRef]:
    # TODO: filter_stage, filter_type

    if url and not url_surt:
        url = surt_ify(url)

    search = Search(using=es_client, index=es_index)

    if consolidate_works:
        search = search.extra(
            collapse={
                "field": "source_work_ident",
                "inner_hits": {"name": "source_more", "size": 0,},
            }
        )

    if release_ident:
        search = search.filter("term", target_release_ident=release_ident)
    elif work_ident:
        search = search.filter("term", target_work_ident=work_ident)
    elif openlibrary_work:
        search = search.filter("term", target_openlibrary_work=openlibrary_work)
    elif url_surt:
        search = search.filter("term", target_url_surt=url_surt)
    else:
        raise ValueError("require a lookup key")

    # TODO: wrong type, not int? and maybe need to index differently?
    #search = search.sort("source_year")

    return _execute_ref_query(search, limit=limit, offset=offset)

def count_inbound_refs(
    es_client: Any,
    release_ident: Optional[str] = None,
    work_ident: Optional[str] = None,
    openlibrary_work: Optional[str] = None,
    url_surt: Optional[str] = None,
    url: Optional[str] = None,
    filter_stage: List[str] = [],
    filter_type: List[str] = [],
    es_index: str = "fatcat_ref",
) -> int:
    """
    Same parameters as get_inbound_refs(), but returns just a count
    """

    if url and not url_surt:
        url = surt_ify(url)

    search = Search(using=es_client, index=es_index)

    if release_ident:
        search = search.filter("term", target_release_ident=release_ident)
    elif work_ident:
        search = search.filter("term", target_work_ident=work_ident)
    elif openlibrary_work:
        search = search.filter("term", target_openlibrary_work=openlibrary_work)
    elif url_surt:
        search = search.filter("term", target_url_surt=url_surt)
    else:
        raise ValueError("require a lookup key")

    return search.count()

def _release_access(release: ReleaseEntity) -> List[AccessOption]:
    """
    Extracts access options from a release.
    """
    options = []
    for f in (release.files or []):
        for u in (f.urls or []):
            if '://web.archive.org/' in u.url:
                return [AccessOption(
                    access_type="wayback",
                    access_url=u.url,
                    mimetype=f.mimetype,
                    size_bytes=f.size,
                    thumbnail_url=None
                )]
            elif '://archive.org/' in u.url:
                return [AccessOption(
                    access_type="ia_file",
                    access_url=u.url,
                    mimetype=f.mimetype,
                    size_bytes=f.size,
                    thumbnail_url=None
                )]
    return options

# run elasticsearch mget query for all ref idents and include "enriched" refs when possible
# for outbound URL refs, would do wayback CDX fetches to find a direct wayback URL
# TODO: for openlibrary, would this query openlibrary.org API? or some fatcat-specific index?
#enrich_inbound_refs(refs: List[BiblioRef]) -> List[CslBiblioRef]
#enrich_outbound_refs(refs: List[BiblioRef]) -> List[CslBiblioRef]

# run fatcat API fetches for each ref and return "enriched" refs
def enrich_inbound_refs_fatcat(refs: List[BiblioRef], fatcat_api_client: Any, hide: Optional[str] = "refs", expand: Optional[str] = "container,files,webcaptures,filesets") -> List[FatcatBiblioRef]:
    enriched = []
    for ref in refs:
        if ref.source_release_ident:
            release = fatcat_api_client.get_release(ref.source_release_ident, hide=hide, expand=expand)
            enriched.append(FatcatBiblioRef(
                ref=ref,
                csl=None,
                access=_release_access(release),
                release=release,
            ))
        else:
            enriched.append(FatcatBiblioRef(
                ref=ref,
                csl=None,
                access=[],
                release=None,
            ))
    return enriched

def enrich_outbound_refs_fatcat(refs: List[BiblioRef], fatcat_api_client: Any, hide: Optional[str] = "refs", expand: Optional[str] = "container,files,webcaptures,filesets") -> List[FatcatBiblioRef]:
    enriched = []
    for ref in refs:
        if ref.target_release_ident:
            release = fatcat_api_client.get_release(ref.target_release_ident, hide=hide, expand=expand)
            enriched.append(FatcatBiblioRef(
                ref=ref,
                csl=None,
                access=_release_access(release),
                release=release,
            ))
        else:
            enriched.append(FatcatBiblioRef(
                ref=ref,
                csl=None,
                access=[],
                release=None,
            ))
    return enriched


def run_ref_query(args) -> None:
    release_ident = None
    work_ident = None
    if args.ident.startswith("release_"):
        release_ident = args.ident.split('_')[1]
    elif args.ident.startswith("work_"):
        work_ident = args.ident.split('_')[1]
    else:
        release_ident = args.ident

    print("## Outbound References")
    hits = get_outbound_refs(release_ident=release_ident, work_ident=work_ident, es_client=args.es_client)
    print(f"Total: {hits.count_total}  Time: {hits.query_wall_time_ms}ms; {hits.query_time_ms}ms")

    if args.enrich == "fatcat":
        enriched = enrich_outbound_refs_fatcat(hits.result_refs, hide='refs,abstracts', fatcat_api_client=args.fatcat_api_client)
        for ref in enriched:
            if ref.release:
                print(f"{ref.ref.ref_index or '-'}\trelease_{ref.release.ident}\t{ref.ref.match_provenance}/{ref.ref.match_status}\t{ref.release.release_year or '-'}\t{ref.release.title}\t{ref.release.ext_ids.pmid or ref.release.ext_ids.doi or '-'}")
            else:
                print(f"{ref.ref.ref_index or '-'}\trelease_{ref.target_release_ident}")
    else:
        for ref in hits.result_refs:
            print(f"{ref.ref.ref_index or '-'}\trelease_{ref.target_release_ident}")

    print()
    print("## Inbound References")
    hits = get_inbound_refs(release_ident=release_ident, work_ident=work_ident, es_client=args.es_client)

    print(f"Total: {hits.count_total}  Time: {hits.query_wall_time_ms}ms; {hits.query_time_ms}ms")

    if args.enrich == "fatcat":
        enriched = enrich_inbound_refs_fatcat(hits.result_refs, hide='refs,abstracts', fatcat_api_client=args.fatcat_api_client)
        for ref in enriched:
            if ref.release:
                print(f"release_{ref.release.ident}\t{ref.ref.match_provenance}/{ref.ref.match_status}\t{ref.release.release_year or '-'}\t{ref.release.title}\t{ref.release.ext_ids.pmid or ref.release.ext_ids.doi or '-'}")
            else:
                print(f"release_{ref.target_release_ident}")
    else:
        for ref in hits.result_refs:
            print(f"work_{ref.source_work_ident}\trelease_{ref.source_release_ident}")

def main() -> None:
    """
    Run this utility like:

        python -m fatcat_tools.references

    Examples:

        python -m fatcat_tools.references query release_pfrind3kh5hqhgqkueulk2tply
    """

    parser = argparse.ArgumentParser(
        formatter_class=argparse.ArgumentDefaultsHelpFormatter
    )
    subparsers = parser.add_subparsers()

    parser.add_argument("--fatcat-api-base", default="https://api.fatcat.wiki/v0")
    parser.add_argument("--elasticsearch-base", default="https://search.fatcat.wiki")
    parser.add_argument("--elasticsearch-ref-index", default="fatcat_ref")

    sub = subparsers.add_parser(
        "query",
        help="takes a fatcat ident argument, prints both inbound and outbound references",
    )
    sub.set_defaults(func="run_ref_query")
    sub.add_argument("ident", type=str)
    sub.add_argument("--enrich", type=str)

    args = parser.parse_args()
    if not args.__dict__.get("func"):
        parser.print_help(file=sys.stderr)
        sys.exit(-1)

    args.es_client = elasticsearch.Elasticsearch(args.elasticsearch_base)
    args.fatcat_api_client = public_api(args.fatcat_api_base)

    if args.func == "run_ref_query":
        run_ref_query(args)
    else:
        raise NotImplementedError(args.func)

if __name__ == "__main__":
    main()