"""Supplier Catalog Blueprint — parts from suppliers with vehicle compatibility.

Independent from inventory. Supports:
- Browse by supplier/category
- Search by text or vehicle (MYE or make/model/year)
- Part detail with compatibilities and interchanges
- Bulk import via Excel
"""

from flask import Blueprint, request, jsonify, g, render_template
from psycopg2.extras import RealDictCursor

from tenant_db import get_master_conn
from middleware import require_auth

supplier_catalog_bp = Blueprint('supplier_catalog', __name__, url_prefix='/pos/api/supplier-catalog')


# ─── Helpers ───────────────────────────────────────────────────────────────

def _get_master_conn():
    return get_master_conn()


def _json_response(data, status=200):
    return jsonify(data), status


# ─── Brands ────────────────────────────────────────────────────────────────

@supplier_catalog_bp.route('/brands', methods=['GET'])
@require_auth('catalog.view')
def list_brands():
    """Return distinct makes (vehicle brands) present in the supplier catalog."""
    conn = _get_master_conn()
    cur = conn.cursor()
    cur.execute("""
        SELECT DISTINCT make, COUNT(*) as cnt
        FROM supplier_catalog_compat
        WHERE make IS NOT NULL AND make != ''
        GROUP BY make
        ORDER BY make ASC
    """)
    rows = cur.fetchall()
    cur.close(); conn.close()
    return jsonify({'brands': [{'name': r[0], 'count': r[1]} for r in rows]})


# ─── Search ────────────────────────────────────────────────────────────────

@supplier_catalog_bp.route('/search', methods=['GET'])
@require_auth('catalog.view')
def search_items():
    """Search supplier catalog by text and/or vehicle."""
    q = (request.args.get('q') or '').strip()
    mye_id = request.args.get('mye_id', type=int)
    make = (request.args.get('make') or '').strip()
    model = (request.args.get('model') or '').strip()
    year = request.args.get('year', type=int)
    supplier = (request.args.get('supplier') or '').strip()
    category = (request.args.get('category') or '').strip()
    page = max(1, request.args.get('page', 1, type=int))
    per_page = min(100, request.args.get('per_page', 30, type=int))
    offset = (page - 1) * per_page

    conn = _get_master_conn()
    cur = conn.cursor()

    # Build query dynamically
    where_parts = ["sc.is_active = true"]
    params = []

    if supplier:
        where_parts.append("sc.supplier_name = %s")
        params.append(supplier)
    if category:
        where_parts.append("sc.category = %s")
        params.append(category)

    # Text search on SKU, name, or interchange part_number
    if q:
        where_parts.append("""
            (sc.sku ILIKE %s OR sc.name ILIKE %s
             OR EXISTS (
                 SELECT 1 FROM supplier_catalog_interchange sci2
                 WHERE sci2.catalog_id = sc.id AND sci2.part_number ILIKE %s
             ))
        """)
        like_q = f'%{q}%'
        params.extend([like_q, like_q, like_q])

    # Vehicle filter
    vehicle_join = ""
    if mye_id:
        vehicle_join = "JOIN supplier_catalog_compat scc ON scc.catalog_id = sc.id"
        where_parts.append("scc.model_year_engine_id = %s")
        params.append(mye_id)
    elif make or model or year:
        vehicle_join = "JOIN supplier_catalog_compat scc ON scc.catalog_id = sc.id"
        if make:
            where_parts.append("scc.make ILIKE %s")
            params.append(f'%{make}%')
        if model:
            where_parts.append("scc.model ILIKE %s")
            params.append(f'%{model}%')
        if year:
            where_parts.append("scc.year = %s")
            params.append(year)

    where_sql = " AND ".join(where_parts)

    # Count total
    count_sql = f"""
        SELECT COUNT(DISTINCT sc.id)
        FROM supplier_catalog sc
        {vehicle_join}
        WHERE {where_sql}
    """
    cur.execute(count_sql, params)
    total = cur.fetchone()[0]

    # Fetch page
    fetch_sql = f"""
        SELECT DISTINCT
            sc.id, sc.supplier_name, sc.sku, sc.name,
            sc.category, sc.description, sc.image_url
        FROM supplier_catalog sc
        {vehicle_join}
        WHERE {where_sql}
        ORDER BY sc.name ASC
        LIMIT %s OFFSET %s
    """
    cur.execute(fetch_sql, params + [per_page, offset])
    rows = cur.fetchall()

    items = []
    for r in rows:
        items.append({
            'id': r[0],
            'supplier_name': r[1],
            'sku': r[2],
            'name': r[3],
            'category': r[4],
            'description': r[5],
            'image_url': r[6],
        })

    cur.close(); conn.close()
    return jsonify({
        'data': items,
        'pagination': {
            'page': page,
            'per_page': per_page,
            'total': total,
            'total_pages': (total + per_page - 1) // per_page,
        }
    })


# ─── Item Detail ───────────────────────────────────────────────────────────

@supplier_catalog_bp.route('/items/<int:item_id>', methods=['GET'])
@require_auth('catalog.view')
def get_item_detail(item_id):
    """Return full detail for a supplier catalog item including compat + interchanges."""
    conn = _get_master_conn()
    cur = conn.cursor()

    cur.execute("""
        SELECT id, supplier_name, sku, name, category, description, image_url, created_at
        FROM supplier_catalog WHERE id = %s AND is_active = true
    """, (item_id,))
    row = cur.fetchone()
    if not row:
        cur.close(); conn.close()
        return jsonify({'error': 'Item not found'}), 404

    item = {
        'id': row[0],
        'supplier_name': row[1],
        'sku': row[2],
        'name': row[3],
        'category': row[4],
        'description': row[5],
        'image_url': row[6],
        'created_at': str(row[7]) if row[7] else None,
    }

    # Compatibilities — deduplicate by (make, model, year, engine) because
    # the same vehicle may map to multiple MYE ids (especially when engine
    # text is empty from the supplier catalog).
    cur.execute("""
        SELECT make, model, year, engine, model_year_engine_id, source
        FROM supplier_catalog_compat
        WHERE catalog_id = %s
        ORDER BY make, model, year, engine
    """, (item_id,))
    seen_compat = set()
    compatibilities = []
    for r in cur.fetchall():
        key = (r[0], r[1], r[2], r[3])
        if key in seen_compat:
            continue
        seen_compat.add(key)
        compatibilities.append({
            'make': r[0], 'model': r[1], 'year': r[2], 'engine': r[3],
            'model_year_engine_id': r[4], 'source': r[5]
        })
    item['compatibilities'] = compatibilities

    # Interchanges
    cur.execute("""
        SELECT brand, part_number
        FROM supplier_catalog_interchange
        WHERE catalog_id = %s
        ORDER BY brand, part_number
    """, (item_id,))
    item['interchanges'] = [
        {'brand': r[0], 'part_number': r[1]}
        for r in cur.fetchall()
    ]

    cur.close(); conn.close()
    return jsonify(item)


# ─── Categories ────────────────────────────────────────────────────────────

@supplier_catalog_bp.route('/categories', methods=['GET'])
@require_auth('catalog.view')
def list_categories():
    """Return distinct categories with counts."""
    conn = _get_master_conn()
    cur = conn.cursor()
    cur.execute("""
        SELECT category, COUNT(*) as cnt
        FROM supplier_catalog
        WHERE is_active = true
        GROUP BY category
        ORDER BY cnt DESC
    """)
    rows = cur.fetchall()
    cur.close(); conn.close()
    return jsonify({'categories': [{'name': r[0], 'count': r[1]} for r in rows]})


# ─── Suppliers ─────────────────────────────────────────────────────────────

@supplier_catalog_bp.route('/suppliers', methods=['GET'])
@require_auth('catalog.view')
def list_suppliers():
    """Return distinct suppliers with counts."""
    conn = _get_master_conn()
    cur = conn.cursor()
    cur.execute("""
        SELECT supplier_name, COUNT(*) as cnt
        FROM supplier_catalog
        WHERE is_active = true
        GROUP BY supplier_name
        ORDER BY supplier_name ASC
    """)
    rows = cur.fetchall()
    cur.close(); conn.close()
    return jsonify({'suppliers': [{'name': r[0], 'count': r[1]} for r in rows]})


# ─── Delete ────────────────────────────────────────────────────────────────

@supplier_catalog_bp.route('/items/<int:item_id>', methods=['DELETE'])
@require_auth('inventory.edit')
def delete_item(item_id):
    """Soft-delete a supplier catalog item."""
    conn = _get_master_conn()
    cur = conn.cursor()
    cur.execute("UPDATE supplier_catalog SET is_active = false WHERE id = %s", (item_id,))
    conn.commit()
    cur.close(); conn.close()
    return jsonify({'success': True})