package service

import (
	"context"
	"crypto/rand"
	"encoding/hex"

	"cid/dao"
	"cid/model/dto"
	"cid/model/entity"

	"github.com/gogf/gf/v2/errors/gerror"
)

type application struct{}

// Application 应用服务
var Application = new(application)

// CreateApplication 创建应用
func (s *application) CreateApplication(ctx context.Context, req *dto.CreateApplicationReq) (id string, err error) {
	// 检查应用名称是否已存在
	existingApp, err := dao.Application.GetByName(ctx, req.Name)
	if err != nil {
		return "", err
	}
	if existingApp != nil {
		return "", gerror.New("应用名称已存在")
	}

	// 生成API密钥
	appKey, appSecret, err := s.generateAPIKeys()
	if err != nil {
		return "", err
	}

	application := &entity.Application{
		Name:        req.Name,
		Code:        req.Code,
		Description: req.Description,
		Platform:    req.Platform,
		PackageName: req.PackageName,
		AppStoreURL: req.AppStoreURL,
		Categories:  req.Categories,
		Tags:        req.Tags,
		AdTypes:     req.AdTypes,
		AppKey:      appKey,
		AppSecret:   appSecret,
		CallbackURL: req.CallbackURL,
	}

	// 设置状态
	application.Status = "active"

	return dao.Application.Create(ctx, application)
}

// UpdateApplication 更新应用
func (s *application) UpdateApplication(ctx context.Context, id string, req *dto.UpdateApplicationReq) (affected int64, err error) {
	// 检查应用是否存在
	existingApp, err := dao.Application.GetByID(ctx, id)
	if err != nil {
		return 0, err
	}
	if existingApp == nil {
		return 0, gerror.New("应用不存在")
	}

	// 如果更新名称，检查是否与其他应用冲突
	if req.Name != "" && req.Name != existingApp.Name {
		conflictApp, err := dao.Application.GetByName(ctx, req.Name)
		if err != nil {
			return 0, err
		}
		if conflictApp != nil && conflictApp.Id.Hex() != id {
			return 0, gerror.New("应用名称已存在")
		}
	}

	// 构建更新数据
	updateData := &entity.Application{}
	if req.Name != "" {
		updateData.Name = req.Name
	}
	if req.Description != "" {
		updateData.Description = req.Description
	}
	if req.Platform != "" {
		updateData.Platform = req.Platform
	}
	if req.PackageName != "" {
		updateData.PackageName = req.PackageName
	}
	if req.AppStoreURL != "" {
		updateData.AppStoreURL = req.AppStoreURL
	}
	if req.CallbackURL != "" {
		updateData.CallbackURL = req.CallbackURL
	}
	if len(req.Categories) > 0 {
		updateData.Categories = req.Categories
	}
	if len(req.Tags) > 0 {
		updateData.Tags = req.Tags
	}
	if len(req.AdTypes) > 0 {
		updateData.AdTypes = req.AdTypes
	}

	// 使用Update方法更新应用
	err = dao.Application.Update(ctx, updateData)
	if err != nil {
		return 0, err
	}
	return 1, nil
}

// GetApplicationsByTenant 获取租户下的应用列表
func (s *application) GetApplicationsByTenant(ctx context.Context, tenantID string, platform, status string, page, size int) (list []*entity.Application, total int64, err error) {
	// 调用DAO的GetByTenantID方法获取租户下的所有应用
	apps, err := dao.Application.GetByTenantID(ctx, tenantID)
	if err != nil {
		return nil, 0, err
	}

	// 应用额外的过滤条件
	var filteredApps []*entity.Application
	for _, app := range apps {
		if platform != "" && app.Platform != platform {
			continue
		}
		if status != "" && app.Status != status {
			continue
		}
		filteredApps = append(filteredApps, app)
	}

	// 实现简单的分页
	startIndex := (page - 1) * size
	endIndex := startIndex + size
	if startIndex >= len(filteredApps) {
		return []*entity.Application{}, int64(len(filteredApps)), nil
	}
	if endIndex > len(filteredApps) {
		endIndex = len(filteredApps)
	}

	return filteredApps[startIndex:endIndex], int64(len(filteredApps)), nil
}

// GetApplicationByKey 根据API密钥获取应用
func (s *application) GetApplicationByKey(ctx context.Context, appKey string) (application *entity.Application, err error) {
	return dao.Application.GetByAPIKey(ctx, appKey)
}

// GetApplicationByID 根据ID获取应用
func (s *application) GetApplicationByID(ctx context.Context, id string) (application *entity.Application, err error) {
	return dao.Application.GetByID(ctx, id)
}

// DeleteApplication 删除应用
func (s *application) DeleteApplication(ctx context.Context, id string) (affected int64, err error) {
	err = dao.Application.Delete(ctx, id)
	if err != nil {
		return 0, err
	}
	return 1, nil
}

// ValidateApplication 验证应用权限
func (s *application) ValidateApplication(ctx context.Context, appKey, appSecret string) (application *entity.Application, err error) {
	app, err := dao.Application.GetByAPIKey(ctx, appKey)
	if err != nil {
		return nil, err
	}
	if app == nil {
		return nil, gerror.New("应用不存在")
	}
	if app.Status != "active" {
		return nil, gerror.New("应用状态异常")
	}
	if app.AppSecret != appSecret {
		return nil, gerror.New("密钥验证失败")
	}

	return app, nil
}

// generateAPIKeys 生成API密钥
func (s *application) generateAPIKeys() (appKey, appSecret string, err error) {
	// 生成32位随机字符串作为AppKey
	keyBytes := make([]byte, 16)
	if _, err := rand.Read(keyBytes); err != nil {
		return "", "", err
	}
	appKey = hex.EncodeToString(keyBytes)

	// 生成64位随机字符串作为AppSecret
	secretBytes := make([]byte, 32)
	if _, err := rand.Read(secretBytes); err != nil {
		return "", "", err
	}
	appSecret = hex.EncodeToString(secretBytes)

	return appKey, appSecret, nil
}

// ResetAPIKeys 重置API密钥
func (s *application) ResetAPIKeys(ctx context.Context, id string) (appKey, appSecret string, err error) {
	// 检查应用是否存在
	existingApp, err := dao.Application.GetByID(ctx, id)
	if err != nil {
		return "", "", err
	}
	if existingApp == nil {
		return "", "", gerror.New("应用不存在")
	}

	// 生成新的API密钥
	appKey, appSecret, err = s.generateAPIKeys()
	if err != nil {
		return "", "", err
	}

	// 更新应用密钥
	updateData := &entity.Application{
		AppKey:    appKey,
		AppSecret: appSecret,
	}
	err = dao.Application.Update(ctx, updateData)
	if err != nil {
		return "", "", err
	}

	return appKey, appSecret, nil
}