package store

import (
	"context"
	"errors"
	"sync"

	"5803025020/w04/internal/models"
	"github.com/google/uuid"
	"github.com/jackc/pgx/v5"
)

// ErrSnippetNotFound dikembalikan saat snippet dengan id yang diminta tidak ada.
var ErrSnippetNotFound = errors.New("snippet not found")

type SnippetStore struct {
	conn *pgx.Conn
	mu   *sync.Mutex
}

func NewSnippetStore(conn *pgx.Conn, optMu ...*sync.Mutex) *SnippetStore {
	var mu *sync.Mutex
	if len(optMu) > 0 && optMu[0] != nil {
		mu = optMu[0]
	} else {
		mu = &sync.Mutex{}
	}
	return &SnippetStore{conn: conn, mu: mu}
}

func (s *SnippetStore) Create(ctx context.Context, snippet *models.Snippet) error {
	s.mu.Lock()
	defer s.mu.Unlock()

	if snippet.ID == "" {
		snippet.ID = uuid.New().String()
	}

	query := `INSERT INTO snippets (id, title, content, user_id) VALUES ($1, $2, $3, $4)`
	_, err := s.conn.Exec(ctx, query, snippet.ID, snippet.Title, snippet.Content, snippet.UserID)
	return err
}

func (s *SnippetStore) GetByID(ctx context.Context, id string) (*models.Snippet, error) {
	s.mu.Lock()
	defer s.mu.Unlock()

	var sn models.Snippet
	query := `SELECT id, title, content, user_id FROM snippets WHERE id = $1`
	err := s.conn.QueryRow(ctx, query, id).Scan(&sn.ID, &sn.Title, &sn.Content, &sn.UserID)
	if err != nil {
		if errors.Is(err, pgx.ErrNoRows) {
			return nil, ErrSnippetNotFound
		}
		return nil, err
	}
	return &sn, nil
}

func (s *SnippetStore) GetByUserID(ctx context.Context, userID string) ([]*models.Snippet, error) {
	s.mu.Lock()
	defer s.mu.Unlock()

	query := `SELECT id, title, content, user_id FROM snippets WHERE user_id = $1`
	rows, err := s.conn.Query(ctx, query, userID)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	snippets := make([]*models.Snippet, 0)
	for rows.Next() {
		var sn models.Snippet
		if err := rows.Scan(&sn.ID, &sn.Title, &sn.Content, &sn.UserID); err != nil {
			return nil, err
		}
		snippets = append(snippets, &sn)
	}
	if err := rows.Err(); err != nil {
		return nil, err
	}
	return snippets, nil
}

func (s *SnippetStore) GetAll(ctx context.Context) ([]*models.Snippet, error) {
	s.mu.Lock()
	defer s.mu.Unlock()

	query := `SELECT id, title, content, user_id FROM snippets`
	rows, err := s.conn.Query(ctx, query)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	snippets := make([]*models.Snippet, 0)
	for rows.Next() {
		var sn models.Snippet
		if err := rows.Scan(&sn.ID, &sn.Title, &sn.Content, &sn.UserID); err != nil {
			return nil, err
		}
		snippets = append(snippets, &sn)
	}
	if err := rows.Err(); err != nil {
		return nil, err
	}
	return snippets, nil
}

// Delete menghapus snippet dengan id tersebut. Jika id tidak ditemukan, ia
// mengembalikan ErrSnippetNotFound.
func (s *SnippetStore) Delete(ctx context.Context, id string) error {
	s.mu.Lock()
	defer s.mu.Unlock()

	query := `DELETE FROM snippets WHERE id = $1`
	tag, err := s.conn.Exec(ctx, query, id)
	if err != nil {
		return err
	}
	if tag.RowsAffected() == 0 {
		return ErrSnippetNotFound
	}
	return nil
}