"""Dropshipping API — public read-only inventory endpoints.

Authentication: X-Dropshipping-Key header (per-tenant).
Optional: X-Tenant-Subdomain for faster resolution.
"""

from flask import Blueprint, request, jsonify, g
from tenant_db import get_tenant_conn, get_master_conn
from services import dropshipping_service as ds_svc
from services.webhook_service import dispatch_webhooks_bulk

dropship_bp = Blueprint("dropship", __name__, url_prefix="/pos/api/dropship")


def _resolve_tenant_by_key(api_key: str, subdomain_hint: str = None):
    """Return (tenant_conn, tenant_id) for a valid dropshipping API key.

    If subdomain_hint is provided, validate only that tenant.
    Otherwise scan active tenants (acceptable for small tenant count).
    """
    master = get_master_conn()
    try:
        cur = master.cursor()
        if subdomain_hint:
            cur.execute(
                "SELECT id, db_name FROM tenants WHERE subdomain = %s AND is_active = true",
                (subdomain_hint,),
            )
            rows = cur.fetchall()
        else:
            cur.execute("SELECT id, db_name FROM tenants WHERE is_active = true")
            rows = cur.fetchall()
        cur.close()

        for tid, db_name in rows:
            try:
                tconn = get_tenant_conn(tid)
                if ds_svc.validate_api_key(tconn, api_key):
                    return tconn, tid
                tconn.close()
            except Exception:
                continue
        return None, None
    finally:
        master.close()


def _require_dropship_auth():
    key = request.headers.get("X-Dropshipping-Key")
    subdomain = request.headers.get("X-Tenant-Subdomain")
    if not key:
        return jsonify({"error": "Missing X-Dropshipping-Key header"}), 401
    tconn, tid = _resolve_tenant_by_key(key, subdomain_hint=subdomain)
    if not tconn:
        return jsonify({"error": "Invalid API key or tenant inactive"}), 401
    g.tenant_id = tid
    g.tenant_conn = tconn
    return None


def _release_tenant():
    if hasattr(g, "tenant_conn") and g.tenant_conn:
        g.tenant_conn.close()


@dropship_bp.route("/inventory", methods=["GET"])
def list_inventory():
    err = _require_dropship_auth()
    if err:
        return err
    try:
        page = int(request.args.get("page", 1))
        per_page = min(int(request.args.get("per_page", 50)), 200)
        search = request.args.get("q")
        result = ds_svc.get_inventory_list(g.tenant_conn, search=search, page=page, per_page=per_page)
        return jsonify(result)
    finally:
        _release_tenant()


@dropship_bp.route("/inventory/<sku>", methods=["GET"])
def get_inventory_item(sku):
    err = _require_dropship_auth()
    if err:
        return err
    try:
        item = ds_svc.get_inventory_by_sku(g.tenant_conn, sku)
        if not item:
            return jsonify({"error": "SKU not found"}), 404
        return jsonify(item)
    finally:
        _release_tenant()


@dropship_bp.route("/stock", methods=["GET"])
def get_stock():
    err = _require_dropship_auth()
    if err:
        return err
    try:
        skus = request.args.get("skus", "")
        sku_list = [s.strip() for s in skus.split(",") if s.strip()]
        if not sku_list:
            return jsonify({"error": "Provide ?skus=SKU1,SKU2,SKU3"}), 400
        result = ds_svc.get_stock_by_skus(g.tenant_conn, sku_list)
        return jsonify({"stock": result})
    finally:
        _release_tenant()


@dropship_bp.route("/webhooks/test", methods=["POST"])
def test_webhook():
    """Test endpoint to trigger a sample webhook to all configured targets."""
    err = _require_dropship_auth()
    if err:
        return err
    try:
        urls = ds_svc.get_webhook_targets(g.tenant_conn, "stock_updated")
        if not urls:
            return jsonify({"error": "No webhook targets configured"}), 400
        results = dispatch_webhooks_bulk(
            urls,
            "test",
            {"message": "Webhook test from Nexus POS", "tenant_id": g.tenant_id},
        )
        return jsonify({"dispatched": len(results), "results": results})
    finally:
        _release_tenant()