"""Repontar a mídia de um projeto para novos arquivos.

Extraído de writer.py — ver fcpxml/writer/__init__.py para o conjunto.
"""

from pathlib import Path
from typing import Any, Dict


class RelinkMixin:
    """Repontar a mídia de um projeto para novos arquivos."""

    # ========================================================================
    # MEDIA RELINK
    # ========================================================================

    def relink_media(
        self,
        find: str,
        replace: str,
        dry_run: bool = False,
    ) -> Dict[str, Any]:
        """Bulk-rewrite media source paths (programmatic relink).

        Rewrites the ``src`` of every ``<asset>`` / ``<media-rep>`` whose
        path starts with *find*, substituting *replace* — the standard
        technique for relinking a moved or renamed media folder without
        opening Final Cut Pro.  FCP relinks via the ``media-rep`` file URL
        on import; the device-specific bookmark blob is left untouched
        (FCP regenerates it).

        *find* / *replace* accept plain paths (``/Volumes/OldDrive``) or
        ``file://`` URLs; percent-encoding in existing URLs is handled.
        Matching is prefix-based on whole path segments, so ``/Media/A``
        matches ``/Media/A/clip.mov`` but not ``/Media/AB/clip.mov``.

        Args:
            find: Old path prefix to match.
            replace: New path prefix to substitute.
            dry_run: When True, report what would change without
                mutating the tree.

        Returns:
            Summary dict: ``total_assets``, ``relinked`` (reference
            count), ``dry_run``, and ``changes`` — a list of
            ``{asset, old, new, target_exists}`` entries
            (``target_exists`` checks the new path on this machine).
        """
        from urllib.parse import quote, unquote, urlparse

        def _to_path(value: str) -> str:
            if value.startswith('file://'):
                return unquote(urlparse(value).path)
            return value

        find_path = _to_path(find).rstrip('/')
        replace_path = _to_path(replace).rstrip('/')
        if not find_path:
            raise ValueError("relink_media: 'find' must be a non-empty path prefix")

        changes = []
        for asset_id, info in self.resources.items():
            elem = info['element']
            targets = [(elem, elem.get('src'))]
            media_rep = elem.find('media-rep')
            if media_rep is not None:
                targets.append((media_rep, media_rep.get('src')))

            for node, old_src in targets:
                if not old_src:
                    continue
                was_url = old_src.startswith('file://')
                old_path = _to_path(old_src)
                if old_path != find_path and not old_path.startswith(find_path + '/'):
                    continue
                new_path = replace_path + old_path[len(find_path):]
                new_src = 'file://' + quote(new_path) if was_url else new_path
                if not dry_run:
                    node.set('src', new_src)
                    info['src'] = new_src
                changes.append({
                    'asset': info.get('name') or asset_id,
                    'old': old_src,
                    'new': new_src,
                    'target_exists': Path(new_path).exists(),
                })

        return {
            'total_assets': len(self.resources),
            'relinked': len(changes),
            'dry_run': dry_run,
            'changes': changes,
        }