package handler

import (
	"encoding/hex"
	"encoding/json"
	"fmt"
	"net/http"
	"time"

	"github.com/jackc/pgx/v5/pgtype"
	db "github.com/multica-ai/multica/server/pkg/db/generated"
	"github.com/multica-ai/multica/server/internal/realtime"
)

type Handler struct {
	Queries *db.Queries
	Hub     *realtime.Hub
}

func New(queries *db.Queries, hub *realtime.Hub) *Handler {
	return &Handler{Queries: queries, Hub: hub}
}

func writeJSON(w http.ResponseWriter, status int, v any) {
	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(status)
	json.NewEncoder(w).Encode(v)
}

func writeError(w http.ResponseWriter, status int, msg string) {
	writeJSON(w, status, map[string]string{"error": msg})
}

func parseUUID(s string) pgtype.UUID {
	var u pgtype.UUID
	_ = u.Scan(s)
	return u
}

func uuidToString(u pgtype.UUID) string {
	if !u.Valid {
		return ""
	}
	b := u.Bytes
	dst := make([]byte, 36)
	hex.Encode(dst[0:8], b[0:4])
	dst[8] = '-'
	hex.Encode(dst[9:13], b[4:6])
	dst[13] = '-'
	hex.Encode(dst[14:18], b[6:8])
	dst[18] = '-'
	hex.Encode(dst[19:23], b[8:10])
	dst[23] = '-'
	hex.Encode(dst[24:36], b[10:16])
	return string(dst)
}

func textToPtr(t pgtype.Text) *string {
	if !t.Valid {
		return nil
	}
	return &t.String
}

func ptrToText(s *string) pgtype.Text {
	if s == nil {
		return pgtype.Text{}
	}
	return pgtype.Text{String: *s, Valid: true}
}

func strToText(s string) pgtype.Text {
	if s == "" {
		return pgtype.Text{}
	}
	return pgtype.Text{String: s, Valid: true}
}

func timestampToString(t pgtype.Timestamptz) string {
	if !t.Valid {
		return ""
	}
	return t.Time.Format(time.RFC3339)
}

func timestampToPtr(t pgtype.Timestamptz) *string {
	if !t.Valid {
		return nil
	}
	s := t.Time.Format(time.RFC3339)
	return &s
}

func uuidToPtr(u pgtype.UUID) *string {
	if !u.Valid {
		return nil
	}
	s := uuidToString(u)
	return &s
}

// broadcast sends a WebSocket event to all connected clients.
func (h *Handler) broadcast(eventType string, payload any) {
	msg := map[string]any{
		"type":    eventType,
		"payload": payload,
	}
	data, err := json.Marshal(msg)
	if err != nil {
		fmt.Printf("broadcast marshal error: %v\n", err)
		return
	}
	h.Hub.Broadcast(data)
}