package sync

import (
	"database/sql"
	"encoding/json"
	"net/http"
	"strconv"
	"time"

	mw "github.com/weltonmoura/initpage/internal/middleware"
)

type Sync struct {
	DB *sql.DB
}

type syncPayload struct {
	Data    json.RawMessage `json:"data"`
	Version int             `json:"version"`
}

func (s *Sync) Get(w http.ResponseWriter, r *http.Request) {
	uid := mw.GetUserID(r.Context())
	if uid == "" {
		w.WriteHeader(http.StatusUnauthorized)
		return
	}
	var data string
	var version int
	var updatedAt string
	_ = s.DB.QueryRow(`SELECT data, version, updated_at FROM user_sync WHERE user_id=?`, uid).Scan(&data, &version, &updatedAt)
	if data == "" {
		w.Header().Set("Content-Type", "application/json")
		w.Write([]byte(`{"data":null,"version":0}`))
		return
	}
	w.Header().Set("Content-Type", "application/json")
	w.Write([]byte(`{"data":` + data + `,"version":` + strconv.Itoa(version) + `}`))
}

func (s *Sync) Put(w http.ResponseWriter, r *http.Request) {
	uid := mw.GetUserID(r.Context())
	if uid == "" {
		w.WriteHeader(http.StatusUnauthorized)
		return
	}
	var p syncPayload
	if err := json.NewDecoder(r.Body).Decode(&p); err != nil {
		w.WriteHeader(http.StatusBadRequest)
		w.Write([]byte(`{"error":"json inválido"}`))
		return
	}
	if len(p.Data) > 256*1024 {
		w.WriteHeader(http.StatusBadRequest)
		w.Write([]byte(`{"error":"dados muito grandes"}`))
		return
	}
	// valida JSON básico
	if !json.Valid(p.Data) {
		w.WriteHeader(http.StatusBadRequest)
		w.Write([]byte(`{"error":"json inválido"}`))
		return
	}
	_, err := s.DB.Exec(`INSERT INTO user_sync(user_id,data,version,updated_at) VALUES(?,?,?,?)
		ON CONFLICT(user_id) DO UPDATE SET data=excluded.data, version=excluded.version, updated_at=excluded.updated_at`,
		uid, string(p.Data), p.Version, time.Now())
	if err != nil {
		w.WriteHeader(http.StatusInternalServerError)
		return
	}
	w.Header().Set("Content-Type", "application/json")
	w.Write([]byte(`{"ok":true}`))
}