## Copyright © 2026 Olaf Kolkman
## SPDX-License-Identifier: GPL-3.0-or-later

import json
from fastapi import APIRouter, Depends, Header, HTTPException, Response, status
import logging
from pydantic import BaseModel

from backend.app.services.link_service import create_link, delete_link, find_owned_link_by_title, find_owned_link_by_title_url, get_link_tags, get_owned_link, list_public_links, list_tags, mark_mastodon_posted, update_link
from backend.app.database import get_connection
from backend.app.services.plugin_manager import plugin_manager
from backend.app.services.token_service import validate_token
from backend.app.services.audit_service import record_audit_event
from backend.app.services.scraper_service import scrape_title

router = APIRouter()
logger = logging.getLogger(__name__)


class LinkCreate(BaseModel):
    title: str
    url: str
    comment: str = ''
    timestamp: str | None = None
    tags: list[str] = []
    post_to_mastodon: bool = True


class LinkUpdate(BaseModel):
    title: str
    url: str
    comment: str = ''
    tags: list[str] = []


@router.get('/tags')
def available_tags():
    return list_tags()


@router.get('/scrape')
def scrape_url(url: str, authorization: str | None = Header(default=None)):
    if not authorization or not authorization.startswith('Bearer '):
        raise HTTPException(status_code=401, detail='Missing or invalid Authorization header')
    info = validate_token(authorization.replace('Bearer ', '', 1))
    if info is None:
        raise HTTPException(status_code=401, detail='Token expired or invalid')
    try:
        title = scrape_title(url)
        return {'title': title}
    except Exception as e:
        logger.error('Scrape error for %s: %s', url, e)
        raise HTTPException(status_code=502, detail='Could not scrape URL') from e


@router.get('/links/check')
def check_existing_link(
    title: str,
    url: str,
    authorization: str | None = Header(default=None),
):
    if not authorization or not authorization.startswith('Bearer '):
        raise HTTPException(status_code=401, detail='Missing or invalid Authorization header')
    info = validate_token(authorization.replace('Bearer ', '', 1))
    if info is None:
        raise HTTPException(status_code=401, detail='Token expired or invalid')
    record = find_owned_link_by_title_url(info['user_id'], title, url)
    if record is not None:
        return {'exists': True, 'url_matches': True, 'stored_url': record['url']}
    record = find_owned_link_by_title(info['user_id'], title)
    if record is not None:
        return {'exists': True, 'url_matches': False, 'stored_url': record['url']}
    return {'exists': False, 'url_matches': None, 'stored_url': None}


@router.post('/links', status_code=status.HTTP_201_CREATED)
def create_link_endpoint(payload: LinkCreate, response: Response, authorization: str | None = Header(default=None)):
    if not authorization or not authorization.startswith('Bearer '):
        raise HTTPException(status_code=401, detail='Missing or invalid Authorization header')
    token = authorization.replace('Bearer ', '', 1)
    info = validate_token(token)
    if info is None:
        raise HTTPException(status_code=401, detail='Token expired or invalid')

    try:
        record = find_owned_link_by_title_url(info['user_id'], payload.title, payload.url)
        duplicate = record is not None
        if duplicate:
            record = update_link(record['id'], info['user_id'], payload.title, payload.url, payload.comment, payload.tags)
        else:
            record = create_link(info['user_id'], payload.title, payload.url, payload.comment, payload.timestamp, payload.tags)
    except ValueError as error:
        raise HTTPException(status_code=422, detail=str(error)) from error
    if duplicate:
        response.status_code = status.HTTP_200_OK
    plugin_results = plugin_manager.dispatch({
        'type': 'link_created',
        'post_to_mastodon': payload.post_to_mastodon,
        **record,
    })
    mastodon_result = next((result for result in plugin_results if result.get('plugin') == 'mastodon'), None)
    if mastodon_result and mastodon_result.get('status') == 'posted':
        mark_mastodon_posted(record['id'], info['user_id'], mastodon_result.get('post_id'))
    if any(result.get('status') == 'failed' for result in plugin_results):
        logger.warning('One or more plugins failed for link_id=%s results=%s', record['id'], plugin_results)
    plugin_errors = [
        {'plugin': result.get('plugin', 'unknown'), 'reason': result.get('reason', 'Plugin failed')}
        for result in plugin_results
        if result.get('status') == 'failed'
    ]
    return {**record, 'duplicate': duplicate, 'plugin_errors': plugin_errors}


@router.put('/links/{link_id}')
def update_link_endpoint(
    link_id: str,
    payload: LinkUpdate,
    authorization: str | None = Header(default=None),
):
    if not authorization or not authorization.startswith('Bearer '):
        raise HTTPException(status_code=401, detail='Missing or invalid Authorization header')
    info = validate_token(authorization.replace('Bearer ', '', 1))
    if info is None:
        raise HTTPException(status_code=401, detail='Token expired or invalid')

    try:
        record = update_link(link_id, info['user_id'], payload.title, payload.url, payload.comment, payload.tags)
    except ValueError as error:
        raise HTTPException(status_code=422, detail=str(error)) from error
    if record is None:
        raise HTTPException(status_code=404, detail='Link not found or not owned by user')
    return record


@router.delete('/links/{link_id}')
def delete_link_endpoint(
    link_id: str,
    authorization: str | None = Header(default=None),
):
    if not authorization or not authorization.startswith('Bearer '):
        raise HTTPException(status_code=401, detail='Missing or invalid Authorization header')
    info = validate_token(authorization.replace('Bearer ', '', 1))
    if info is None:
        raise HTTPException(status_code=401, detail='Token expired or invalid')
    link = get_owned_link(link_id, info['user_id'])
    if link is None:
        raise HTTPException(status_code=404, detail='Link not found or not owned by user')
    post_ids = json.loads(link['mastodon_post_ids']) if link.get('mastodon_post_ids') else []
    if not post_ids and link.get('mastodon_post_id'):
        post_ids = [link['mastodon_post_id']]
    if post_ids:
        result = plugin_manager.delete_mastodon_posts({**link, 'mastodon_post_ids': post_ids})
        if result.get('status') != 'deleted':
            raise HTTPException(status_code=502, detail=result.get('reason', 'Could not delete Mastodon posts'))
    if not delete_link(link_id, info['user_id']):
        raise HTTPException(status_code=404, detail='Link not found or not owned by user')
    record_audit_event(info['user_id'], 'link_deleted', 'link', link_id)
    return {'status': 'deleted', 'id': link_id}


@router.post('/links/{link_id}/mastodon')
def post_link_to_mastodon(
    link_id: str,
    authorization: str | None = Header(default=None),
):
    if not authorization or not authorization.startswith('Bearer '):
        raise HTTPException(status_code=401, detail='Missing or invalid Authorization header')
    info = validate_token(authorization.replace('Bearer ', '', 1))
    if info is None:
        raise HTTPException(status_code=401, detail='Token expired or invalid')
    with get_connection() as conn:
        row = conn.execute('SELECT * FROM links WHERE id = ? AND user_id = ?', (link_id, info['user_id'])).fetchone()
    if row is None:
        raise HTTPException(status_code=404, detail='Link not found or not owned by user')
    event = dict(row)
    with get_connection() as conn:
        event['tags'] = get_link_tags(conn, link_id)
    result = plugin_manager.post_to_mastodon({'type': 'link_created', **event})
    if result.get('status') == 'posted':
        mark_mastodon_posted(link_id, info['user_id'], result.get('post_id'))
        record_audit_event(info['user_id'], 'mastodon_posted', 'link', link_id)
        return {'status': 'posted', 'post_id': result.get('post_id')}
    if result.get('status') == 'skipped':
        raise HTTPException(status_code=409, detail='Mastodon is not enabled or configured')
    raise HTTPException(status_code=502, detail=result.get('reason', 'Mastodon post failed'))


@router.get('/links')
def list_links():
    return list_public_links()