#!/usr/bin/env python3

"""
Transform an OAI-PMH bulk dump (JSON) into ingest requests.

Eg: https://archive.org/details/oai_harvest_20200215
"""

import argparse
import json
import sys

import urlcanon

DOMAIN_BLOCKLIST = [
    # large OA publishers (we get via DOI)

    # large repos and aggregators (we crawl directly)
    "://arxiv.org/",
    "://europepmc.org/",
    "ncbi.nlm.nih.gov/",
    "semanticscholar.org/",
    "://doi.org/",
    "://dx.doi.org/",
    "zenodo.org/",
    "figshare.com/",
    "://archive.org/",
    ".archive.org/",
    "://127.0.0.1/",

    # OAI specific additions
    "://hdl.handle.net/",
]

RELEASE_STAGE_MAP = {
    'info:eu-repo/semantics/draftVersion':     'draft',
    'info:eu-repo/semantics/submittedVersion': 'submitted',
    'info:eu-repo/semantics/acceptedVersion':  'accepted',
    'info:eu-repo/semantics/publishedVersion': 'published',
    'info:eu-repo/semantics/updatedVersion':   'updated',
}

def canon(s):
    parsed = urlcanon.parse_url(s)
    return str(urlcanon.whatwg(parsed))

def transform(obj):
    """
    Transforms from a single OAI-PMH object to zero or more ingest requests.
    Returns a list of dicts.
    """

    requests = []
    if not obj.get('oai') or not obj['oai'].startswith('oai:'):
        return []
    if not obj.get('urls'):
        return []

    # look in obj['formats'] for PDF?
    if obj.get('formats'):
        # if there is a list of formats, and it does not contain PDF, then
        # skip. Note that we will continue if there is no formats list.
        has_pdf = False
        for f in obj['formats']:
            if 'pdf' in f.lower():
                has_pdf = True
        if not has_pdf:
            return []

    doi = None
    if obj.get('doi'):
        doi = obj['doi'][0].lower().strip()
        if not doi.startswith('10.'):
            doi = None

    # infer release stage and/or type from obj['types']
    release_stage = None
    for t in obj.get('types', []):
        if t in RELEASE_STAGE_MAP:
            release_stage = RELEASE_STAGE_MAP[t]

    # TODO: infer rel somehow? Eg, repository vs. OJS publisher
    rel = None

    for url in obj['urls']:
        skip = False
        for domain in DOMAIN_BLOCKLIST:
            if domain in url:
                skip = True
        if skip:
            continue
        try:
            base_url = canon(url)
        except UnicodeEncodeError:
            continue

        request = {
            'base_url': base_url,
            'ingest_type': 'pdf',
            'link_source': 'oai',
            'link_source_id': obj['oai'].lower(),
            'ingest_request_source': 'metha-bulk',
            'release_stage': release_stage,
            'rel': rel,
            'ext_ids': {
                'doi': doi,
                'oai': obj['oai'].lower(),
            },
            'edit_extra': {},
        }
        requests.append(request)

    return requests

def run(args):
    for l in args.json_file:
        if not l.strip():
            continue
        row = json.loads(l)

        requests = transform(row) or []
        for r in requests:
            print("{}".format(json.dumps(r, sort_keys=True)))

def main():
    parser = argparse.ArgumentParser(
        formatter_class=argparse.ArgumentDefaultsHelpFormatter)
    parser.add_argument('json_file',
        help="OAI-PMH dump file to use (usually stdin)",
        type=argparse.FileType('r'))
    subparsers = parser.add_subparsers()

    args = parser.parse_args()

    run(args)

if __name__ == '__main__':
    main()