package masterdb

import (
	"database/sql"
	"fmt"
	"time"
)

// EdgeRoute records a public route managed by the master.
type EdgeRoute struct {
	Hostname        string
	ServiceName     string
	EdgeNode        string
	BackendHostname string
	BackendPort     int
	CreatedAt       time.Time
}

// CreateEdgeRoute inserts or replaces an edge route record.
func CreateEdgeRoute(db *sql.DB, hostname, serviceName, edgeNode, backendHostname string, backendPort int) error {
	_, err := db.Exec(`
		INSERT INTO edge_routes (hostname, service_name, edge_node, backend_hostname, backend_port, created_at)
		VALUES (?, ?, ?, ?, ?, datetime('now'))
		ON CONFLICT(hostname) DO UPDATE SET
			service_name = excluded.service_name,
			edge_node = excluded.edge_node,
			backend_hostname = excluded.backend_hostname,
			backend_port = excluded.backend_port
	`, hostname, serviceName, edgeNode, backendHostname, backendPort)
	if err != nil {
		return fmt.Errorf("create edge route %s: %w", hostname, err)
	}
	return nil
}

// ListEdgeRoutes returns all edge routes.
func ListEdgeRoutes(db *sql.DB) ([]*EdgeRoute, error) {
	return queryEdgeRoutes(db, `SELECT hostname, service_name, edge_node, backend_hostname, backend_port, created_at FROM edge_routes ORDER BY hostname`)
}

// ListEdgeRoutesForService returns edge routes for a specific service.
func ListEdgeRoutesForService(db *sql.DB, serviceName string) ([]*EdgeRoute, error) {
	rows, err := db.Query(`
		SELECT hostname, service_name, edge_node, backend_hostname, backend_port, created_at
		FROM edge_routes WHERE service_name = ? ORDER BY hostname
	`, serviceName)
	if err != nil {
		return nil, fmt.Errorf("list edge routes for %s: %w", serviceName, err)
	}
	defer func() { _ = rows.Close() }()

	return scanEdgeRoutes(rows)
}

// DeleteEdgeRoute removes a single edge route by hostname.
func DeleteEdgeRoute(db *sql.DB, hostname string) error {
	_, err := db.Exec(`DELETE FROM edge_routes WHERE hostname = ?`, hostname)
	if err != nil {
		return fmt.Errorf("delete edge route %s: %w", hostname, err)
	}
	return nil
}

// DeleteEdgeRoutesForService removes all edge routes for a service.
func DeleteEdgeRoutesForService(db *sql.DB, serviceName string) error {
	_, err := db.Exec(`DELETE FROM edge_routes WHERE service_name = ?`, serviceName)
	if err != nil {
		return fmt.Errorf("delete edge routes for %s: %w", serviceName, err)
	}
	return nil
}

func queryEdgeRoutes(db *sql.DB, query string) ([]*EdgeRoute, error) {
	rows, err := db.Query(query)
	if err != nil {
		return nil, fmt.Errorf("query edge routes: %w", err)
	}
	defer func() { _ = rows.Close() }()

	return scanEdgeRoutes(rows)
}

func scanEdgeRoutes(rows *sql.Rows) ([]*EdgeRoute, error) {
	var routes []*EdgeRoute
	for rows.Next() {
		var r EdgeRoute
		var createdAt string
		if err := rows.Scan(&r.Hostname, &r.ServiceName, &r.EdgeNode, &r.BackendHostname, &r.BackendPort, &createdAt); err != nil {
			return nil, fmt.Errorf("scan edge route: %w", err)
		}
		r.CreatedAt, _ = time.Parse("2006-01-02 15:04:05", createdAt)
		routes = append(routes, &r)
	}
	return routes, rows.Err()
}