/*
Copyright 2025 linux.do
Modified by Arctel.net, 2026

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package model

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

	"github.com/redis/go-redis/v9"
	"github.com/shopspring/decimal"

	"github.com/Rain-kl/Wavelet/internal/db"
)

// 配置键常量 - 所有系统配置的 key 定义
const (
	ConfigKeyUploadAllowedExtensions          = "upload_allowed_extensions"           // 允许上传的文件扩展名，逗号分隔
	ConfigKeySiteName                         = "site_name"                           // 站点名称
	ConfigKeyPasswordLoginEnabled             = "password_login_enabled"              // 是否允许密码登录
	ConfigKeyRegistrationEnabled              = "registration_enabled"                // 是否允许注册
	ConfigKeyPasswordRegisterEnabled          = "password_register_enabled"           // 是否允许密码注册
	ConfigKeyOIDCLoginEnabled                 = "oidc_login_enabled"                  // 是否允许 OIDC 登录
	ConfigKeyMaxAPIKeysPerUser                = "max_api_keys_per_user"               // 每个用户最大 API Key 数量
	ConfigKeyCapLoginEnabled                  = "cap_login_enabled"                   // 是否启用登录人机验证
	ConfigKeyCapAutoSolve                     = "cap_auto_solve"                      // 打开页面后是否自动开始计算（false 则需用户手动点击）
	ConfigKeyCapChallengeCount                = "cap_challenge_count"                 // 客户端需求解的 PoW 难题总数，默认 1，推荐 1～5
	ConfigKeyCapChallengeSize                 = "cap_challenge_size"                  // 人机验证盐值长度
	ConfigKeyCapChallengeDifficulty           = "cap_challenge_difficulty"            // 人机验证 PoW 难度（目标前缀长度）
	ConfigKeyCapChallengeTTL                  = "cap_challenge_ttl_seconds"           // 人机验证难题有效时间（秒）
	ConfigKeyCapTokenTTL                      = "cap_token_ttl_seconds"               // 人机验证兑换凭证有效时间（秒）
	ConfigKeyServerAddress                    = "server_address"                      // 服务器地址
	ConfigKeySMTPHost                         = "smtp_host"                           // SMTP 服务器地址
	ConfigKeySMTPPort                         = "smtp_port"                           // SMTP 端口
	ConfigKeySMTPUsername                     = "smtp_username"                       // SMTP 账户
	ConfigKeySMTPPassword                     = "smtp_password"                       // SMTP 访问凭证
	ConfigKeyEmailLoginVerificationEnabled    = "email_login_verification_enabled"    // 是否启用邮箱登录验证
	ConfigKeyEmailRegisterVerificationEnabled = "email_register_verification_enabled" // 是否启用邮箱注册验证
	ConfigKeyMenuDisplayConfig                = "menu_display_config"                 // 目录显示配置 (JSON 字符串)
)

const (
	// SystemConfigRedisHashKey Redis Hash key，存储所有系统配置
	SystemConfigRedisHashKey = "system:system_configs"
)

type SystemConfig struct {
	Key         string    `json:"key" gorm:"primaryKey;size:64;not null"`
	Value       string    `json:"value" gorm:"size:255;not null"`
	Type        string    `json:"type" gorm:"size:32;not null;default:'system'"`
	Description string    `json:"description" gorm:"size:255"`
	UpdatedAt   time.Time `json:"updated_at" gorm:"autoUpdateTime"`
	CreatedAt   time.Time `json:"created_at" gorm:"autoCreateTime"`
}

// GetByKey 通过 key 查询配置（带 Redis 缓存）
func (sc *SystemConfig) GetByKey(ctx context.Context, key string) error {
	if db.Redis != nil {
		if err := db.HGetJSON(ctx, SystemConfigRedisHashKey, key, sc); err == nil {
			return nil
		} else if !errors.Is(err, redis.Nil) {
			// Redis 服务错误，返回错误
			return err
		}
	}

	// 查数据库
	database := db.DB(ctx)
	if database == nil {
		return errors.New(errDatabaseNotInitialized)
	}

	if err := database.Where("key = ?", key).First(sc).Error; err != nil {
		return err
	}

	// 更新 Redis Hash 缓存
	if db.Redis != nil {
		_ = db.HSetJSON(ctx, SystemConfigRedisHashKey, key, sc)
	}

	return nil
}

// GetIntByKey 通过 key 查询配置并转换为 int 类型
func GetIntByKey(ctx context.Context, key string) (int, error) {
	var sc SystemConfig
	if err := sc.GetByKey(ctx, key); err != nil {
		return 0, err
	}

	value, err := strconv.Atoi(sc.Value)
	if err != nil {
		return 0, fmt.Errorf(errConfigIntParseFailed, key, sc.Value, err)
	}

	return value, nil
}

// GetDecimalByKey 通过 key 查询配置并转换为 decimal.Decimal 类型
// precision 指定保留的小数位数，多余的小数会被裁剪
func GetDecimalByKey(ctx context.Context, key string, precision int32) (decimal.Decimal, error) {
	var sc SystemConfig
	if err := sc.GetByKey(ctx, key); err != nil {
		return decimal.Zero, err
	}

	value, err := decimal.NewFromString(sc.Value)
	if err != nil {
		return decimal.Zero, fmt.Errorf(errConfigDecimalParseFailed, key, sc.Value, err)
	}

	// 裁剪到指定小数位数
	return value.Truncate(precision), nil
}

// GetBoolByKey 通过 key 查询配置并转换为 bool 类型
func GetBoolByKey(ctx context.Context, key string) (bool, error) {
	var sc SystemConfig
	if err := sc.GetByKey(ctx, key); err != nil {
		return false, err
	}

	value, err := strconv.ParseBool(sc.Value)
	if err != nil {
		return false, fmt.Errorf(errConfigBoolParseFailed, key, sc.Value, err)
	}

	return value, nil
}

// GetMenuDisplayConfig 获取目录显示配置，解析为 map[string]bool
func GetMenuDisplayConfig(ctx context.Context) (map[string]bool, error) {
	var sc SystemConfig
	if err := sc.GetByKey(ctx, ConfigKeyMenuDisplayConfig); err != nil {
		return nil, err
	}

	config := make(map[string]bool)
	if sc.Value == "" || sc.Value == "{}" {
		return config, nil
	}

	if err := json.Unmarshal([]byte(sc.Value), &config); err != nil {
		return nil, fmt.Errorf(errParseMenuDisplayConfigFailed, err)
	}

	return config, nil
}