#!/usr/bin/env python3
"""Build and merge shopping list for Bilka ToGo.

Flow:
1) Build Mealie shopping list from meal plan entries in the Friday-Thursday window.
2) Merge those Mealie shopping items with a local Google Keep base list.

Output:
- /www/bilka_togo_checklist.md
- /www/bilka_togo_checklist_bilka.md
- /www/bilka_togo_checklist.json
"""

from __future__ import annotations

import json
import re
import urllib.request
from collections import defaultdict
from datetime import date, timedelta
from pathlib import Path


ROOT_CANDIDATES = [Path('/Volumes/homeassistant'), Path('/config')]
MEALIE_BASE_URL = 'http://10.0.0.142:9925'
TARGET_SHOPPING_LIST_NAME = 'Bilka ToGo'
CATEGORY_RULES = {
    'frugt & grønt': ['banan', 'aeble', 'æble', 'citron', 'lime', 'tomat', 'salat', 'agurk', 'gulerod', 'kartoffel', 'log', 'løg', 'hvidlog', 'hvidløg', 'broccoli', 'spidskal', 'spidskål', 'avocado', 'peberfrugt'],
    'kød & fisk': ['kylling', 'oksekød', 'hakket', 'ribeye', 'bacon', 'laks', 'fisk', 'skinke', 'pølse'],
    'mejeri & æg': ['mælk', 'yoghurt', 'smør', 'ost', 'feta', 'mozzarella', 'æg', 'fløde', 'creme fraiche'],
    'kolonial': ['ris', 'pasta', 'mel', 'havregryn', 'olie', 'eddike', 'krydder', 'bønne', 'linse', 'dåse', 'sukker', 'salt', 'tomatpuré', 'tomatpure', 'nori', 'soja'],
    'frost': ['frost', 'frossen', 'is', 'edamame'],
    'husholdning': ['toiletpapir', 'køkkenrulle', 'kokkenrulle', 'sæbe', 'sæb', 'opvasketabs', 'vaskemiddel', 'affaldspose'],
}


def detect_root() -> Path:
    # Prefer repository-relative root so the script works both in HA (/config)
    # and when run locally from the mounted workspace (/Volumes/homeassistant).
    local_root = Path(__file__).resolve().parent.parent
    if (local_root / 'secrets.yaml').exists():
        return local_root
    for root in ROOT_CANDIDATES:
        if (root / 'secrets.yaml').exists():
            return root
    raise RuntimeError('Could not locate Home Assistant config root')


def read_bearer_token(secrets_path: Path) -> str:
    for line in secrets_path.read_text().splitlines():
        if line.strip().startswith('mealie_bearer_token:'):
            return line.split(':', 1)[1].strip().strip('"')
    raise RuntimeError('mealie_bearer_token not found in secrets.yaml')


def api_get(url: str, token: str) -> dict:
    req = urllib.request.Request(url, headers={'Authorization': token})
    with urllib.request.urlopen(req, timeout=20) as resp:
        raw = resp.read()
    return json.loads(raw) if raw else {}


def api_request(
    base_url: str,
    path: str,
    token: str,
    method: str = 'GET',
    payload: dict | list | None = None,
    timeout: int = 90,
):
    data = None
    headers = {'Authorization': token}
    if payload is not None:
        data = json.dumps(payload).encode('utf-8')
        headers['Content-Type'] = 'application/json'
    req = urllib.request.Request(f'{base_url}{path}', headers=headers, data=data, method=method)
    with urllib.request.urlopen(req, timeout=timeout) as resp:
        raw = resp.read()
    if not raw:
        return {}
    try:
        return json.loads(raw)
    except json.JSONDecodeError:
        return {}


def normalize_name(value: str) -> str:
    value = value.lower().strip()
    value = value.replace('å', 'aa').replace('æ', 'ae').replace('ø', 'oe')
    value = re.sub(r'\s+', ' ', value)
    value = re.sub(r'[^a-z0-9 ]', '', value)
    return value


def classify_category(name: str) -> str:
    key = normalize_name(name)
    for category, needles in CATEGORY_RULES.items():
        for needle in needles:
            if needle in key:
                return category
    return 'andet'


def read_keep_items(keep_path: Path) -> list[str]:
    if not keep_path.exists():
        return []
    items: list[str] = []
    for line in keep_path.read_text().splitlines():
        stripped = line.strip()
        if not stripped or stripped.startswith('#'):
            continue
        items.append(stripped)
    return items


def friday_to_thursday_window(today: date) -> tuple[date, date]:
    days_until_friday = (4 - today.weekday()) % 7
    start = today + timedelta(days=days_until_friday)
    end = start + timedelta(days=6)
    return start, end


def ensure_shopping_list(base_url: str, token: str, name: str) -> str:
    lists = api_request(base_url, '/api/households/shopping/lists?perPage=200', token).get('items', []) or []
    for shopping_list in lists:
        if (shopping_list.get('name') or '').strip().lower() == name.lower():
            return shopping_list['id']

    created = api_request(
        base_url,
        '/api/households/shopping/lists',
        token,
        method='POST',
        payload={'name': name},
    )
    return created['id']


def clear_shopping_list_items(base_url: str, token: str, shopping_list_id: str) -> None:
    items = api_request(base_url, '/api/households/shopping/items?perPage=1000', token).get('items', []) or []
    for item in items:
        if item.get('shoppingListId') == shopping_list_id and item.get('id'):
            api_request(base_url, f"/api/households/shopping/items/{item['id']}", token, method='DELETE')


def get_mealplan_recipe_ids(base_url: str, token: str, start_date: date, end_date: date) -> list[str]:
    entries: list[dict] = []
    current = start_date
    while current <= end_date:
        path = (
            f"/api/households/mealplans?start_date={current.isoformat()}"
            f"&end_date={current.isoformat()}&perPage=100"
        )
        day_payload = api_request(base_url, path, token)
        day_items = day_payload.get('items', []) if isinstance(day_payload, dict) else []
        entries.extend(day_items or [])
        current = current + timedelta(days=1)

    result: list[str] = []
    seen: set[str] = set()
    for entry in entries:
        recipe_id = entry.get('recipeId')
        if not recipe_id:
            continue
        if recipe_id in seen:
            continue
        seen.add(recipe_id)
        result.append(recipe_id)
    return result


def add_recipes_to_shopping_list(base_url: str, token: str, shopping_list_id: str, recipe_ids: list[str]) -> int:
    if not recipe_ids:
        return 0

    payload = [{'recipeId': rid, 'recipeIncrementQuantity': 1} for rid in recipe_ids]
    api_request(
        base_url,
        f'/api/households/shopping/lists/{shopping_list_id}/recipe',
        token,
        method='POST',
        payload=payload,
    )
    return len(recipe_ids)


def fetch_mealie_items(base_url: str, token: str, shopping_list_id: str | None = None) -> list[dict]:
    data = api_request(base_url, '/api/households/shopping/items?perPage=1000', token)
    items = data.get('items', []) or []
    if not shopping_list_id:
        return items
    return [item for item in items if item.get('shoppingListId') == shopping_list_id]


def extract_item_name(item: dict) -> str:
    display = (item.get('display') or '').strip()
    if display:
        return display
    food = item.get('food') or {}
    return (food.get('name') or '').strip()


def merge_items(mealie_items: list[dict], keep_items: list[str]) -> list[dict]:
    merged: dict[str, dict] = {}

    for item in mealie_items:
        name = extract_item_name(item)
        if not name:
            continue
        norm = normalize_name(name)
        if norm not in merged:
            merged[norm] = {
                'name': name,
                'category': classify_category(name),
                'sources': set(),
            }
        merged[norm]['sources'].add('Mealie')

    for name in keep_items:
        norm = normalize_name(name)
        if norm not in merged:
            merged[norm] = {
                'name': name,
                'category': classify_category(name),
                'sources': set(),
            }
        merged[norm]['sources'].add('Google Keep')

    result = []
    for _, row in merged.items():
        result.append(
            {
                'name': row['name'],
                'category': row['category'],
                'sources': sorted(row['sources']),
            }
        )

    result.sort(key=lambda x: (x['category'], normalize_name(x['name'])))
    return result


def write_outputs(root: Path, items: list[dict], start_date: date, end_date: date) -> None:
    www = root / 'www'
    www.mkdir(parents=True, exist_ok=True)

    payload = {'count': len(items), 'items': items}
    (www / 'bilka_togo_checklist.json').write_text(json.dumps(payload, ensure_ascii=False, indent=2))

    grouped: dict[str, list[dict]] = defaultdict(list)
    for item in items:
        grouped[item['category']].append(item)

    lines = [
        '# Bilka ToGo - Kryds-af-liste',
        '',
        'Gå listen igennem derhjemme først, og bestil kun de varer du mangler.',
        f'Plan-vindue: {start_date.isoformat()} til {end_date.isoformat()}',
        '',
    ]

    for category in sorted(grouped.keys()):
        lines.append(f'## {category.title()}')
        for item in grouped[category]:
            sources = '/'.join(item['sources'])
            lines.append(f"- [ ] {item['name']} ({sources})")
        lines.append('')

    (www / 'bilka_togo_checklist.md').write_text('\n'.join(lines))

    # Bilka-ready checklist: same grouped list, but without source metadata.
    bilka_lines = [
        '# Bilka ToGo - Klar til bestilling',
        '',
        'Kryds af hvad I allerede har i huset, og bestil resten.',
        f'Plan-vindue: {start_date.isoformat()} til {end_date.isoformat()}',
        '',
    ]

    for category in sorted(grouped.keys()):
        bilka_lines.append(f'## {category.title()}')
        for item in grouped[category]:
            bilka_lines.append(f"- [ ] {item['name']}")
        bilka_lines.append('')

    (www / 'bilka_togo_checklist_bilka.md').write_text('\n'.join(bilka_lines))


def main() -> None:
    root = detect_root()
    token = read_bearer_token(root / 'secrets.yaml')
    keep_path = root / 'dokumenter' / 'google_keep_indkoeb.txt'

    start_date, end_date = friday_to_thursday_window(date.today())

    shopping_list_id = ensure_shopping_list(MEALIE_BASE_URL, token, TARGET_SHOPPING_LIST_NAME)
    clear_shopping_list_items(MEALIE_BASE_URL, token, shopping_list_id)

    recipe_ids = get_mealplan_recipe_ids(MEALIE_BASE_URL, token, start_date, end_date)
    added_recipes = add_recipes_to_shopping_list(MEALIE_BASE_URL, token, shopping_list_id, recipe_ids)

    mealie_items = fetch_mealie_items(MEALIE_BASE_URL, token, shopping_list_id=shopping_list_id)
    keep_items = read_keep_items(keep_path)

    merged = merge_items(mealie_items, keep_items)
    write_outputs(root, merged, start_date, end_date)

    print(
        'OK: '
        f'window={start_date.isoformat()}..{end_date.isoformat()} '
        f'recipes_added={added_recipes} merged_items={len(merged)}'
    )


if __name__ == '__main__':
    main()