package repository

import (
	"context"

	"code.nochebuena.dev/go/sqlite"
	"code.nochebuena.dev/go/todo-api/internal/domain"
)

// TodoRepository defines persistence operations for todos.
type TodoRepository interface {
	FindAll(ctx context.Context) ([]domain.Todo, error)
	Create(ctx context.Context, todo domain.Todo) (domain.Todo, error)
}

type todoRepository struct {
	db sqlite.Client
}

// NewTodoRepository returns a SQLite-backed TodoRepository.
func NewTodoRepository(db sqlite.Client) TodoRepository {
	return &todoRepository{db: db}
}

func (r *todoRepository) FindAll(ctx context.Context) ([]domain.Todo, error) {
	rows, err := r.db.GetExecutor(ctx).QueryContext(ctx,
		`SELECT id, title, done, created_at FROM todos ORDER BY created_at DESC`,
	)
	if err != nil {
		return nil, r.db.HandleError(err)
	}
	defer rows.Close()

	var todos []domain.Todo
	for rows.Next() {
		var t domain.Todo
		if err := rows.Scan(&t.ID, &t.Title, &t.Done, &t.CreatedAt); err != nil {
			return nil, err
		}
		todos = append(todos, t)
	}
	if err := rows.Err(); err != nil {
		return nil, err
	}
	if todos == nil {
		todos = []domain.Todo{} // always return a slice, never nil
	}
	return todos, nil
}

func (r *todoRepository) Create(ctx context.Context, todo domain.Todo) (domain.Todo, error) {
	row := r.db.GetExecutor(ctx).QueryRowContext(ctx,
		`INSERT INTO todos (title, done) VALUES (?, ?) RETURNING id, title, done, created_at`,
		todo.Title, todo.Done,
	)
	var t domain.Todo
	if err := row.Scan(&t.ID, &t.Title, &t.Done, &t.CreatedAt); err != nil {
		return domain.Todo{}, r.db.HandleError(err)
	}
	return t, nil
}