# License: GNU AGPL v3: http://www.gnu.org/licenses/
# This file is part of `delarte` (https://git.afpy.org/fcode/delarte.git)

"""Provide ArteTV website utilities."""

import json

from .error import InvalidPage, PageNotFound, PageNotSupported, HTTPError
from .model import Program

_DATA_MARK = '<script id="__NEXT_DATA__" type="application/json">'


def _process_programs_page(page_value):
    language = page_value["language"]

    zone_found = False
    program_found = False

    for zone in page_value["zones"]:
        if zone["code"].startswith("program_content_"):
            if zone_found:
                raise InvalidPage("PROGRAMS_CONTENT_ZONES_COUNT")
            zone_found = True
        else:
            continue

        for data_item in zone["content"]["data"]:
            if data_item["type"] == "program":
                if program_found:
                    raise InvalidPage("PROGRAMS_CONTENT_PROGRAM_COUNT")
                program_found = True
            else:
                raise InvalidPage("PROGRAMS_CONTENT_PROGRAM_TYPE")

            yield (
                Program(
                    data_item["programId"],
                    language,
                    data_item["title"],
                    data_item["subtitle"],
                ),
                data_item["player"]["config"],
            )

    if not zone_found:
        raise InvalidPage("PROGRAMS_CONTENT_ZONES_COUNT")

    if not program_found:
        raise InvalidPage("PROGRAMS_CONTENT_PROGRAM_COUNT")


def _process_collections_page(page_value):
    language = page_value["language"]

    main_zone_found = False
    sub_zone_found = False
    program_found = False

    for zone in page_value["zones"]:
        if zone["code"].startswith("collection_videos_"):
            if main_zone_found:
                raise InvalidPage("COLLECTIONS_MAIN_ZONE_COUNT")
            if program_found:
                raise InvalidPage("COLLECTIONS_MIXED_ZONES")
            main_zone_found = True
        elif zone["code"].startswith("collection_subcollection_"):
            if program_found and not sub_zone_found:
                raise InvalidPage("COLLECTIONS_MIXED_ZONES")
            sub_zone_found = True
        else:
            continue

        for data_item in zone["content"]["data"]:
            if (_ := data_item["type"]) == "teaser":
                program_found = True
            else:
                raise InvalidPage("COLLECTIONS_INVALID_CONTENT_DATA_ITEM", _)

            yield (
                Program(
                    data_item["programId"],
                    language,
                    data_item["title"],
                    data_item["subtitle"],
                ),
                f"https://api.arte.tv/api/player/v2/config/{language}/{data_item['programId']}",
            )

    if not main_zone_found:
        raise InvalidPage("COLLECTIONS_MAIN_ZONE_COUNT")

    if not program_found:
        raise InvalidPage("COLLECTIONS_PROGRAMS_COUNT")


def iter_programs(page_url, http):
    """Iterate over programs listed on given ArteTV page."""
    r = http.request("GET", page_url)

    # special handling of 404
    if r.status == 404:
        raise PageNotFound(page_url)
    HTTPError.raise_for_status(r)

    # no HTML parsing required, whe just find the mark
    html = r.data.decode("utf-8")
    start = html.find(_DATA_MARK)
    if start < 0:
        raise InvalidPage("DATA_MARK_NOT_FOUND", page_url)
    start += len(_DATA_MARK)
    end = html.index("</script>", start)

    try:
        next_js_data = json.loads(html[start:end].strip())
    except json.JSONDecodeError:
        raise InvalidPage("INVALID_JSON_DATA", page_url)

    try:
        page_value = next_js_data["props"]["pageProps"]["props"]["page"]["value"]

        match page_value["type"]:
            case "program":
                yield from _process_programs_page(page_value)
            case "collection":
                yield from _process_collections_page(page_value)
            case _:
                raise PageNotSupported(page_url, page_value)

    except (KeyError, IndexError, ValueError) as e:
        raise InvalidPage("SCHEMA", page_url) from e

    except InvalidPage as e:
        raise InvalidPage(e.args[0], page_url) from e