import argparse
import os
from dataclasses import dataclass
from datetime import datetime
from typing import Optional, Set

import requests

from ..manifest import manifest
from ..wpt import metadata, virtualenv

here = os.path.dirname(__file__)
wpt_root = os.path.abspath(os.path.join(here, os.pardir, os.pardir))


@dataclass
class InteropYear:
    year: int
    end_date: datetime


all_interop_years = [
    InteropYear(2025, datetime(2026, 2, 12)),
    InteropYear(2026, datetime(2027, 2, 11)),
]


def get_parser() -> argparse.ArgumentParser:
    parser = argparse.ArgumentParser()
    parser.add_argument(
        "--manifest", dest="manifest_path", help="Path to MANIFEST.json"
    )
    parser.add_argument("metadata_path", help="Path to wpt metadata repository")
    return parser


def get_labels(interop_years: Set[int]) -> Set[str]:
    data_url = "https://raw.githubusercontent.com/web-platform-tests/wpt.fyi/refs/heads/main/webapp/static/interop-data.json"
    resp = requests.get(data_url)
    resp.raise_for_status()
    data = resp.json()
    labels = set()
    for interop_year in interop_years:
        try:
            focus_areas = data[str(interop_year)]["focus_areas"]
        except Exception:
            # TODO: log error here
            pass
        for focus_area in focus_areas.values():
            labels |= set(focus_area["labels"])

    return labels


def run_update_codeowners(
    venv: virtualenv.Virtualenv,
    metadata_path: str,
    manifest_path: Optional[str],
    reviewer: Optional[str] = "@web-platform-tests/interop",
) -> int:
    if manifest_path is None:
        manifest_path = os.path.join(wpt_root, "MANIFEST.json")
    wpt_manifest = manifest.load_and_update(wpt_root, manifest_path, "/")

    interop_years = {
        item.year for item in all_interop_years if item.end_date >= datetime.today()
    }

    labels = get_labels(interop_years)
    metadata_map = metadata.load_metadata_map(metadata_path)
    tests_by_label = metadata.get_labelled_tests(metadata_map, list(labels))
    all_labelled_tests = set()
    for labelled_tests in tests_by_label.values():
        all_labelled_tests |= set(labelled_tests)

    test_lines = []
    for _test_type, rel_path, tests in wpt_manifest:
        if any(test.id in all_labelled_tests for test in tests):
            test_lines.append(f"{rel_path} {reviewer}\n")

    output = []
    start_line = "# GENERATED: interop-tests"
    end_line = "# END GENERATED"
    in_generated = False
    found_generated = False
    with open(os.path.join(wpt_root, "CODEOWNERS")) as f:
        for line in f:
            if not in_generated:
                if line.strip() == start_line:
                    output.append(line)
                    found_generated = True
                    in_generated = True
                    output.extend(test_lines)
                else:
                    output.append(line)
            else:
                if line.strip() == end_line:
                    in_generated = False
                    output.append(line)
    if not found_generated:
        output.extend(["\n", start_line + "\n"] + test_lines + [end_line + "\n"])
    with open(os.path.join(wpt_root, "CODEOWNERS"), "w") as f:
        f.writelines(output)

    return 0