package tokens

import (
	"context"
	"database/sql"
	"encoding/json"
	"fmt"
	"time"

	"atlas9.dev/c/core"
)

type PostgresStore[T any] struct {
	db   *sql.DB
	opts Options
}

func NewPostgresStore[T any](db *sql.DB, opts Options) *PostgresStore[T] {
	return &PostgresStore[T]{db: db, opts: opts}
}

func (s *PostgresStore[T]) Put(ctx context.Context, key string, data T) (*Token[T], error) {
	dataJSON, err := json.Marshal(data)
	if err != nil {
		return nil, fmt.Errorf("marshaling token data: %w", err)
	}

	expiresAt := time.Now().UTC().Add(s.opts.Expiration)

	_, err = s.db.ExecContext(ctx,
		"INSERT INTO "+s.opts.Table+" (key, data, expires_at) VALUES ($1, $2, $3) ON CONFLICT (key) DO UPDATE SET data = $2, expires_at = $3",
		key, dataJSON, expiresAt)
	if err != nil {
		return nil, fmt.Errorf("storing token: %w", err)
	}

	return &Token[T]{Key: key, ExpiresAt: expiresAt, Data: data}, nil
}

func (s *PostgresStore[T]) Get(ctx context.Context, key string) (*Token[T], error) {
	var dataJSON []byte
	var expiresAt time.Time
	err := s.db.QueryRowContext(ctx,
		"SELECT data, expires_at FROM "+s.opts.Table+" WHERE key = $1 AND expires_at > now()",
		key).Scan(&dataJSON, &expiresAt)

	if err == sql.ErrNoRows {
		return nil, core.ErrNotFound
	}
	if err != nil {
		return nil, fmt.Errorf("getting token: %w", err)
	}

	var data T
	if err := json.Unmarshal(dataJSON, &data); err != nil {
		return nil, fmt.Errorf("unmarshaling token data: %w", err)
	}

	return &Token[T]{Key: key, ExpiresAt: expiresAt, Data: data}, nil
}

func (s *PostgresStore[T]) Delete(ctx context.Context, key string) error {
	_, err := s.db.ExecContext(ctx,
		"DELETE FROM "+s.opts.Table+" WHERE key = $1", key)
	if err != nil {
		return fmt.Errorf("deleting token: %w", err)
	}
	return nil
}