package session

import (
	"context"
	"encoding/json"
	"errors"
	"time"

	"github.com/redis/go-redis/v9"
)

const keyPrefix = "omnex:session:"

// RedisManager : Manager adossé à Redis.
type RedisManager struct {
	rdb *redis.Client
	ttl time.Duration
}

func NewRedisManager(rdb *redis.Client, ttl time.Duration) *RedisManager {
	return &RedisManager{rdb: rdb, ttl: ttl}
}

func (m *RedisManager) TTL() time.Duration { return m.ttl }

func (m *RedisManager) Create(ctx context.Context, s Session) (string, error) {
	token, err := newToken()
	if err != nil {
		return "", err
	}
	s.CreatedAt = time.Now().UTC()
	data, err := json.Marshal(s)
	if err != nil {
		return "", err
	}
	if err := m.rdb.Set(ctx, keyPrefix+token, data, m.ttl).Err(); err != nil {
		return "", err
	}
	return token, nil
}

func (m *RedisManager) Get(ctx context.Context, token string) (Session, bool, error) {
	if token == "" {
		return Session{}, false, nil
	}
	data, err := m.rdb.Get(ctx, keyPrefix+token).Bytes()
	if errors.Is(err, redis.Nil) {
		return Session{}, false, nil
	}
	if err != nil {
		return Session{}, false, err
	}
	var s Session
	if err := json.Unmarshal(data, &s); err != nil {
		return Session{}, false, err
	}
	return s, true, nil
}

func (m *RedisManager) Delete(ctx context.Context, token string) error {
	if token == "" {
		return nil
	}
	return m.rdb.Del(ctx, keyPrefix+token).Err()
}