# app/main.py

from flask import Blueprint, render_template, flash, redirect, url_for, abort, send_from_directory, request, jsonify

from sqlalchemy import desc, func, text
from sqlalchemy.orm import joinedload

from app.models import ImageRecord, Tag, ArchiveRecord, image_tags
from app import db
import os
import shutil

main = Blueprint('main', __name__)


@main.route('/')
def index():
    """
    Showcase view: full-bleed masonry collage of random images/videos.
    """
    images = (
        ImageRecord.query
        .options(joinedload(ImageRecord.tags))
        .order_by(func.random())
        .limit(20)
        .all()
    )
    return render_template('showcase.html', images=images)


@main.route('/api/random-images')
def random_images_api():
    """
    JSON endpoint returning random images for shuffle/infinite scroll.

    Query params:
      - count: number of images to return (default 12)
      - exclude: comma-separated list of image IDs to exclude (for infinite scroll)
    """
    count = request.args.get('count', 12, type=int)
    exclude_str = request.args.get('exclude', '')

    # Parse exclusion list
    exclude_ids = []
    if exclude_str:
        try:
            exclude_ids = [int(x) for x in exclude_str.split(',') if x.strip()]
        except ValueError:
            pass

    # Build query
    q = ImageRecord.query.options(joinedload(ImageRecord.tags))

    if exclude_ids:
        q = q.filter(~ImageRecord.id.in_(exclude_ids))

    images = q.order_by(func.random()).limit(count).all()

    result = []
    for img in images:
        is_video = img.filename.lower().endswith(('.mp4', '.mov'))
        thumb_path = (img.thumb_path or img.filepath).replace('/images/', '')
        full_path = img.filepath.replace('/images/', '')

        result.append({
            'id': img.id,
            'filename': img.filename,
            'thumb_url': url_for('main.serve_image', filename=thumb_path),
            'full_url': url_for('main.serve_image', filename=full_path),
            'is_video': is_video,
            'date': (img.taken_at or img.imported_at).strftime('%Y-%m-%d') if (img.taken_at or img.imported_at) else '',
            'tags': [{'name': t.name, 'kind': t.kind} for t in img.tags]
        })

    return jsonify(images=result)


@main.route('/gallery')
def gallery():
    """
    Gallery with pagination and optional tag filter (?tag=artist:NAME or any tag name).
    Keeps your pagination shape so modal-pagination.js continues to work.
    """
    page = request.args.get('page', 1, type=int)
    per_page = request.args.get('per_page', 35, type=int)
    tag_name = request.args.get('tag')

    # Base query + eager-load tags (cheap and future-proofs tag chips)
    q = ImageRecord.query.options(joinedload(ImageRecord.tags))

    # Optional tag filter
    if tag_name:
        q = q.join(ImageRecord.tags).filter(Tag.name == tag_name)

    images = q.order_by(desc(func.coalesce(ImageRecord.taken_at, ImageRecord.imported_at))) \
              .paginate(page=page, per_page=per_page)

    # Preserve next/prev URLs (carry tag= so modal pagination fetches stay filtered)
    next_url = url_for('main.gallery', page=images.next_num, per_page=per_page, tag=tag_name) if images.has_next else ''
    prev_url = url_for('main.gallery', page=images.prev_num, per_page=per_page, tag=tag_name) if images.has_prev else ''

    return render_template(
        'gallery.html',
        images=images,
        active_tag=tag_name,
        has_next=images.has_next,
        next_page_url=next_url,
        has_prev=images.has_prev,
        prev_page_url=prev_url
    )


@main.route('/images/<path:filename>')
def serve_image(filename):
    return send_from_directory('/images', filename)


@main.route('/tags')
def tag_list():
    """
    Generic tag explorer:
      /tags            -> all tags
      /tags?kind=user  -> only user tags
      /tags?kind=artist -> only artist tags
      /tags?kind=archive -> only archive tags
      /tags?kind=character -> only character tags
      /tags?kind=series -> only series tags
      /tags?kind=rating -> only rating tags
    Shows a few preview images per tag.
    """
    images_per_tag = 3
    kind = request.args.get('kind')  # 'artist' | 'archive' | 'user' | 'character' | 'series' | 'rating' | None

    # Get tags with image counts
    q = db.session.query(
        Tag,
        func.count(image_tags.c.image_id).label('img_count')
    ).outerjoin(image_tags).group_by(Tag.id)

    if kind:
        q = q.filter(Tag.kind == kind)

    tags_with_counts = q.order_by(Tag.name.asc()).all()

    tag_data = []
    for t, count in tags_with_counts:
        imgs = (
            ImageRecord.query
            .join(ImageRecord.tags)
            .filter(Tag.id == t.id)
            .order_by(desc(func.coalesce(ImageRecord.taken_at, ImageRecord.imported_at)))
            .limit(images_per_tag)
            .all()
        )
        # Display label: for prefixed kinds use the part after ':', else full name
        label = t.name.split(":", 1)[1] if (":" in t.name) else t.name
        tag_data.append({
            "id": t.id,
            "name": label,
            "tag": t.name,
            "images": imgs,
            "kind": t.kind,
            "count": count
        })

    return render_template('tags_list.html',
                           tag_data=tag_data,
                           images_per_tag=images_per_tag,
                           active_kind=kind)

@main.route('/artists')
def artist_list():
    # Backward-compatible route that now shows the Tag Explorer filtered to artist tags
    return redirect(url_for('main.tag_list', kind='artist'))

@main.route('/artist/<artist_name>')
def artist_gallery(artist_name):
    # Backward-compatible: go to gallery filtered by artist tag
    return redirect(url_for('main.gallery', tag=f"artist:{artist_name}"))


@main.route('/settings')
def settings():
    return render_template('settings.html')


@main.route('/trigger-thumbnail-generation', methods=['POST'])
def trigger_thumbnail_generation():
    try:
        with open('/import/thumbnail.flag', 'w') as f:
            f.write("trigger")
        flash("Thumbnail regeneration has been triggered.", "success")
    except Exception as e:
        flash(f"Failed to trigger thumbnail regeneration: {e}", "danger")

    return redirect(url_for('main.settings'))


@main.route('/import-images')
def trigger_image_import():
    with open('/import/trigger.flag', 'w') as f:
        f.write('start')
    flash("Image import triggered.", "success")
    return redirect(url_for('main.settings'))


@main.route('/reset-db', methods=['POST'])
def reset_db():
    """
    Safe reset that works with Postgres (TRUNCATE ... CASCADE).
    Falls back to ordered deletes if TRUNCATE isn't supported (e.g., SQLite).
    """
    try:
        # Postgres fast path
        db.session.execute(text("""
            TRUNCATE TABLE image_tags, archive_record, image_record, tag
            RESTART IDENTITY CASCADE
        """))
        db.session.commit()
    except Exception:
        # Fallback: manual delete order
        db.session.execute(image_tags.delete())
        ArchiveRecord.query.delete()
        ImageRecord.query.delete()
        Tag.query.delete()
        db.session.commit()

    # Optional: clear thumbs on disk to regenerate fresh
    shutil.rmtree("/images/thumbs", ignore_errors=True)
    os.makedirs("/images/thumbs", exist_ok=True)

    flash("Database has been reset. All records removed.", "info")
    return redirect(url_for('main.settings'))


# ----------------------------
# Tag add/remove endpoints
# ----------------------------

@main.get("/api/tags/search")
def search_tags():
    """
    Search existing tags for autocomplete.
    Query params:
      - q: search query (matches tag name, case-insensitive)
      - limit: max results (default 10)
    """
    query = request.args.get('q', '').strip().lower()
    limit = request.args.get('limit', 10, type=int)

    if not query:
        # Return most-used tags when no query
        tags = (
            Tag.query
            .join(image_tags)
            .group_by(Tag.id)
            .order_by(func.count(image_tags.c.image_id).desc())
            .limit(limit)
            .all()
        )
    else:
        tags = (
            Tag.query
            .filter(Tag.name.ilike(f'%{query}%'))
            .order_by(Tag.name)
            .limit(limit)
            .all()
        )

    return jsonify(tags=[{"name": t.name, "kind": t.kind} for t in tags])


@main.get("/image/<int:image_id>/tags")
def list_tags(image_id):
    img = ImageRecord.query.get_or_404(image_id)
    return jsonify(ok=True, tags=[{"name": t.name, "kind": t.kind} for t in img.tags])


@main.post("/image/<int:image_id>/tags/add")
def add_tag(image_id):
    """
    Minimal JSON endpoint to add a tag to an image.
    Accepts either 'artist:NAME' / 'archive:...' or a bare freeform tag ('mytag').
    """
    name = (request.form.get("name") or "").strip()
    if not name:
        abort(400)

    # Normalize: keep explicit kind prefixes, otherwise treat as user tag
    if ":" in name:
        kind = name.split(":", 1)[0]
        tag_name = name
    else:
        kind = "user"
        tag_name = name

    img = ImageRecord.query.get_or_404(image_id)
    tag = Tag.query.filter_by(name=tag_name).first()
    if not tag:
        tag = Tag(name=tag_name, kind=kind)
        db.session.add(tag)
        db.session.flush()
    if tag not in img.tags:
        img.tags.append(tag)
        db.session.commit()
    return jsonify(ok=True, tag={"name": tag.name, "kind": tag.kind})


@main.post("/image/<int:image_id>/tags/remove")
def remove_tag(image_id):
    """
    Minimal JSON endpoint to remove a tag from an image.
    """
    name = (request.form.get("name") or "").strip()
    img = ImageRecord.query.get_or_404(image_id)
    tag = Tag.query.filter_by(name=name).first()
    if tag and tag in img.tags:
        img.tags.remove(tag)
        db.session.commit()
    return jsonify(ok=True)


# ----------------------------
# Tag management endpoints
# ----------------------------

@main.get("/api/tag/<int:tag_id>")
def get_tag(tag_id):
    """Get a single tag's details."""
    tag = Tag.query.get_or_404(tag_id)
    # Get display name (without prefix)
    display_name = tag.name.split(":", 1)[1] if ":" in tag.name else tag.name
    return jsonify(ok=True, tag={
        "id": tag.id,
        "name": tag.name,
        "display_name": display_name,
        "kind": tag.kind
    })


@main.post("/api/tag/<int:tag_id>/update")
def update_tag(tag_id):
    """
    Update a tag's name and/or kind.
    For prefixed kinds (artist, archive, character, series, rating),
    the name will be stored as 'kind:name'.

    If the new name matches an existing tag, merge them:
    - Move all images from source tag to target tag
    - Delete the source tag
    - Return the target tag info with merged=True
    """
    tag = Tag.query.get_or_404(tag_id)

    new_name = (request.form.get("name") or "").strip()
    new_kind = (request.form.get("kind") or "user").strip()
    force_merge = request.form.get("merge") == "true"

    if not new_name:
        return jsonify(ok=False, error="Name is required"), 400

    # Build the full tag name based on kind
    prefixed_kinds = ("artist", "archive", "character", "series", "rating")
    if new_kind in prefixed_kinds:
        # Remove any existing prefix from name if present
        if ":" in new_name:
            new_name = new_name.split(":", 1)[1]
        full_name = f"{new_kind}:{new_name}"
    else:
        # User tags don't have prefixes
        full_name = new_name

    # Check for duplicates (excluding current tag)
    existing = Tag.query.filter(Tag.name == full_name, Tag.id != tag_id).first()
    if existing:
        if not force_merge:
            # Ask user to confirm merge
            return jsonify(
                ok=False,
                error="A tag with this name already exists",
                can_merge=True,
                target_tag={
                    "id": existing.id,
                    "name": existing.name,
                    "kind": existing.kind
                }
            ), 409  # Conflict status

        # Merge: move all images from source tag to target tag
        source_images = tag.images[:]  # Copy list to avoid mutation during iteration
        merged_count = 0
        for img in source_images:
            if existing not in img.tags:
                img.tags.append(existing)
                merged_count += 1
            img.tags.remove(tag)

        # Delete the source tag
        db.session.delete(tag)
        db.session.commit()

        return jsonify(ok=True, merged=True, merged_count=merged_count, tag={
            "id": existing.id,
            "name": existing.name,
            "kind": existing.kind
        })

    # No conflict - just update the tag
    tag.name = full_name
    tag.kind = new_kind
    db.session.commit()

    return jsonify(ok=True, tag={
        "id": tag.id,
        "name": tag.name,
        "kind": tag.kind
    })


@main.post("/api/tag/<int:tag_id>/delete")
def delete_tag(tag_id):
    """Delete a tag entirely."""
    tag = Tag.query.get_or_404(tag_id)

    # Remove from all images first (handled by cascade, but explicit is clearer)
    db.session.delete(tag)
    db.session.commit()

    return jsonify(ok=True)