package controller

import (
	"strconv"
	"strings"

	"github.com/QuantumNous/new-api/common"
	"github.com/QuantumNous/new-api/model"
	"github.com/QuantumNous/new-api/setting/ratio_setting"
	"github.com/gin-gonic/gin"
	"gorm.io/gorm"
)

// ---- Shared types ----

type SubscriptionPlanDTO struct {
	Plan model.SubscriptionPlan `json:"plan"`
}

type BillingPreferenceRequest struct {
	BillingPreference string `json:"billing_preference"`
}

// ---- User APIs ----

func GetSubscriptionPlans(c *gin.Context) {
	var plans []model.SubscriptionPlan
	if err := model.DB.Where("enabled = ?", true).Order("sort_order desc, id desc").Find(&plans).Error; err != nil {
		common.ApiError(c, err)
		return
	}
	result := make([]SubscriptionPlanDTO, 0, len(plans))
	for _, p := range plans {
		result = append(result, SubscriptionPlanDTO{
			Plan: p,
		})
	}
	common.ApiSuccess(c, result)
}

func GetSubscriptionSelf(c *gin.Context) {
	userId := c.GetInt("id")
	settingMap, _ := model.GetUserSetting(userId, false)
	pref := common.NormalizeBillingPreference(settingMap.BillingPreference)

	// Get all subscriptions (including expired)
	allSubscriptions, err := model.GetAllUserSubscriptions(userId)
	if err != nil {
		allSubscriptions = []model.SubscriptionSummary{}
	}

	// Get active subscriptions for backward compatibility
	activeSubscriptions, err := model.GetAllActiveUserSubscriptions(userId)
	if err != nil {
		activeSubscriptions = []model.SubscriptionSummary{}
	}

	common.ApiSuccess(c, gin.H{
		"billing_preference": pref,
		"subscriptions":      activeSubscriptions, // all active subscriptions
		"all_subscriptions":  allSubscriptions,    // all subscriptions including expired
	})
}

func UpdateSubscriptionPreference(c *gin.Context) {
	userId := c.GetInt("id")
	var req BillingPreferenceRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		common.ApiErrorMsg(c, "参数错误")
		return
	}
	pref := common.NormalizeBillingPreference(req.BillingPreference)

	user, err := model.GetUserById(userId, true)
	if err != nil {
		common.ApiError(c, err)
		return
	}
	current := user.GetSetting()
	current.BillingPreference = pref
	user.SetSetting(current)
	if err := user.Update(false); err != nil {
		common.ApiError(c, err)
		return
	}
	common.ApiSuccess(c, gin.H{"billing_preference": pref})
}

// ---- Admin APIs ----

func AdminListSubscriptionPlans(c *gin.Context) {
	var plans []model.SubscriptionPlan
	if err := model.DB.Order("sort_order desc, id desc").Find(&plans).Error; err != nil {
		common.ApiError(c, err)
		return
	}
	result := make([]SubscriptionPlanDTO, 0, len(plans))
	for _, p := range plans {
		result = append(result, SubscriptionPlanDTO{
			Plan: p,
		})
	}
	common.ApiSuccess(c, result)
}

type AdminUpsertSubscriptionPlanRequest struct {
	Plan model.SubscriptionPlan `json:"plan"`
}

func AdminCreateSubscriptionPlan(c *gin.Context) {
	var req AdminUpsertSubscriptionPlanRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		common.ApiErrorMsg(c, "参数错误")
		return
	}
	req.Plan.Id = 0
	if strings.TrimSpace(req.Plan.Title) == "" {
		common.ApiErrorMsg(c, "套餐标题不能为空")
		return
	}
	if req.Plan.PriceAmount < 0 {
		common.ApiErrorMsg(c, "价格不能为负数")
		return
	}
	if req.Plan.PriceAmount > 9999 {
		common.ApiErrorMsg(c, "价格不能超过9999")
		return
	}
	if req.Plan.Currency == "" {
		req.Plan.Currency = "USD"
	}
	req.Plan.Currency = "USD"
	if req.Plan.DurationUnit == "" {
		req.Plan.DurationUnit = model.SubscriptionDurationMonth
	}
	if req.Plan.DurationValue <= 0 && req.Plan.DurationUnit != model.SubscriptionDurationCustom {
		req.Plan.DurationValue = 1
	}
	if req.Plan.MaxPurchasePerUser < 0 {
		common.ApiErrorMsg(c, "购买上限不能为负数")
		return
	}
	if req.Plan.TotalAmount < 0 {
		common.ApiErrorMsg(c, "总额度不能为负数")
		return
	}
	req.Plan.UpgradeGroup = strings.TrimSpace(req.Plan.UpgradeGroup)
	if req.Plan.UpgradeGroup != "" {
		if _, ok := ratio_setting.GetGroupRatioCopy()[req.Plan.UpgradeGroup]; !ok {
			common.ApiErrorMsg(c, "升级分组不存在")
			return
		}
	}
	req.Plan.QuotaResetPeriod = model.NormalizeResetPeriod(req.Plan.QuotaResetPeriod)
	if req.Plan.QuotaResetPeriod == model.SubscriptionResetCustom && req.Plan.QuotaResetCustomSeconds <= 0 {
		common.ApiErrorMsg(c, "自定义重置周期需大于0秒")
		return
	}
	err := model.DB.Create(&req.Plan).Error
	if err != nil {
		common.ApiError(c, err)
		return
	}
	model.InvalidateSubscriptionPlanCache(req.Plan.Id)
	common.ApiSuccess(c, req.Plan)
}

func AdminUpdateSubscriptionPlan(c *gin.Context) {
	id, _ := strconv.Atoi(c.Param("id"))
	if id <= 0 {
		common.ApiErrorMsg(c, "无效的ID")
		return
	}
	var req AdminUpsertSubscriptionPlanRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		common.ApiErrorMsg(c, "参数错误")
		return
	}
	if strings.TrimSpace(req.Plan.Title) == "" {
		common.ApiErrorMsg(c, "套餐标题不能为空")
		return
	}
	if req.Plan.PriceAmount < 0 {
		common.ApiErrorMsg(c, "价格不能为负数")
		return
	}
	if req.Plan.PriceAmount > 9999 {
		common.ApiErrorMsg(c, "价格不能超过9999")
		return
	}
	req.Plan.Id = id
	if req.Plan.Currency == "" {
		req.Plan.Currency = "USD"
	}
	req.Plan.Currency = "USD"
	if req.Plan.DurationUnit == "" {
		req.Plan.DurationUnit = model.SubscriptionDurationMonth
	}
	if req.Plan.DurationValue <= 0 && req.Plan.DurationUnit != model.SubscriptionDurationCustom {
		req.Plan.DurationValue = 1
	}
	if req.Plan.MaxPurchasePerUser < 0 {
		common.ApiErrorMsg(c, "购买上限不能为负数")
		return
	}
	if req.Plan.TotalAmount < 0 {
		common.ApiErrorMsg(c, "总额度不能为负数")
		return
	}
	req.Plan.UpgradeGroup = strings.TrimSpace(req.Plan.UpgradeGroup)
	if req.Plan.UpgradeGroup != "" {
		if _, ok := ratio_setting.GetGroupRatioCopy()[req.Plan.UpgradeGroup]; !ok {
			common.ApiErrorMsg(c, "升级分组不存在")
			return
		}
	}
	req.Plan.QuotaResetPeriod = model.NormalizeResetPeriod(req.Plan.QuotaResetPeriod)
	if req.Plan.QuotaResetPeriod == model.SubscriptionResetCustom && req.Plan.QuotaResetCustomSeconds <= 0 {
		common.ApiErrorMsg(c, "自定义重置周期需大于0秒")
		return
	}

	err := model.DB.Transaction(func(tx *gorm.DB) error {
		// update plan (allow zero values updates with map)
		updateMap := map[string]interface{}{
			"title":                      req.Plan.Title,
			"subtitle":                   req.Plan.Subtitle,
			"price_amount":               req.Plan.PriceAmount,
			"currency":                   req.Plan.Currency,
			"duration_unit":              req.Plan.DurationUnit,
			"duration_value":             req.Plan.DurationValue,
			"custom_seconds":             req.Plan.CustomSeconds,
			"enabled":                    req.Plan.Enabled,
			"sort_order":                 req.Plan.SortOrder,
			"stripe_price_id":            req.Plan.StripePriceId,
			"creem_product_id":           req.Plan.CreemProductId,
			"max_purchase_per_user":      req.Plan.MaxPurchasePerUser,
			"total_amount":               req.Plan.TotalAmount,
			"upgrade_group":              req.Plan.UpgradeGroup,
			"quota_reset_period":         req.Plan.QuotaResetPeriod,
			"quota_reset_custom_seconds": req.Plan.QuotaResetCustomSeconds,
			"updated_at":                 common.GetTimestamp(),
		}
		if err := tx.Model(&model.SubscriptionPlan{}).Where("id = ?", id).Updates(updateMap).Error; err != nil {
			return err
		}
		return nil
	})
	if err != nil {
		common.ApiError(c, err)
		return
	}
	model.InvalidateSubscriptionPlanCache(id)
	common.ApiSuccess(c, nil)
}

type AdminUpdateSubscriptionPlanStatusRequest struct {
	Enabled *bool `json:"enabled"`
}

func AdminUpdateSubscriptionPlanStatus(c *gin.Context) {
	id, _ := strconv.Atoi(c.Param("id"))
	if id <= 0 {
		common.ApiErrorMsg(c, "无效的ID")
		return
	}
	var req AdminUpdateSubscriptionPlanStatusRequest
	if err := c.ShouldBindJSON(&req); err != nil || req.Enabled == nil {
		common.ApiErrorMsg(c, "参数错误")
		return
	}
	if err := model.DB.Model(&model.SubscriptionPlan{}).Where("id = ?", id).Update("enabled", *req.Enabled).Error; err != nil {
		common.ApiError(c, err)
		return
	}
	model.InvalidateSubscriptionPlanCache(id)
	common.ApiSuccess(c, nil)
}

type AdminBindSubscriptionRequest struct {
	UserId int `json:"user_id"`
	PlanId int `json:"plan_id"`
}

func AdminBindSubscription(c *gin.Context) {
	var req AdminBindSubscriptionRequest
	if err := c.ShouldBindJSON(&req); err != nil || req.UserId <= 0 || req.PlanId <= 0 {
		common.ApiErrorMsg(c, "参数错误")
		return
	}
	msg, err := model.AdminBindSubscription(req.UserId, req.PlanId, "")
	if err != nil {
		common.ApiError(c, err)
		return
	}
	if msg != "" {
		common.ApiSuccess(c, gin.H{"message": msg})
		return
	}
	common.ApiSuccess(c, nil)
}

// ---- Admin: user subscription management ----

func AdminListUserSubscriptions(c *gin.Context) {
	userId, _ := strconv.Atoi(c.Param("id"))
	if userId <= 0 {
		common.ApiErrorMsg(c, "无效的用户ID")
		return
	}
	subs, err := model.GetAllUserSubscriptions(userId)
	if err != nil {
		common.ApiError(c, err)
		return
	}
	common.ApiSuccess(c, subs)
}

type AdminCreateUserSubscriptionRequest struct {
	PlanId int `json:"plan_id"`
}

// AdminCreateUserSubscription creates a new user subscription from a plan (no payment).
func AdminCreateUserSubscription(c *gin.Context) {
	userId, _ := strconv.Atoi(c.Param("id"))
	if userId <= 0 {
		common.ApiErrorMsg(c, "无效的用户ID")
		return
	}
	var req AdminCreateUserSubscriptionRequest
	if err := c.ShouldBindJSON(&req); err != nil || req.PlanId <= 0 {
		common.ApiErrorMsg(c, "参数错误")
		return
	}
	msg, err := model.AdminBindSubscription(userId, req.PlanId, "")
	if err != nil {
		common.ApiError(c, err)
		return
	}
	if msg != "" {
		common.ApiSuccess(c, gin.H{"message": msg})
		return
	}
	common.ApiSuccess(c, nil)
}

// AdminInvalidateUserSubscription cancels a user subscription immediately.
func AdminInvalidateUserSubscription(c *gin.Context) {
	subId, _ := strconv.Atoi(c.Param("id"))
	if subId <= 0 {
		common.ApiErrorMsg(c, "无效的订阅ID")
		return
	}
	msg, err := model.AdminInvalidateUserSubscription(subId)
	if err != nil {
		common.ApiError(c, err)
		return
	}
	if msg != "" {
		common.ApiSuccess(c, gin.H{"message": msg})
		return
	}
	common.ApiSuccess(c, nil)
}

// AdminDeleteUserSubscription hard-deletes a user subscription.
func AdminDeleteUserSubscription(c *gin.Context) {
	subId, _ := strconv.Atoi(c.Param("id"))
	if subId <= 0 {
		common.ApiErrorMsg(c, "无效的订阅ID")
		return
	}
	msg, err := model.AdminDeleteUserSubscription(subId)
	if err != nil {
		common.ApiError(c, err)
		return
	}
	if msg != "" {
		common.ApiSuccess(c, gin.H{"message": msg})
		return
	}
	common.ApiSuccess(c, nil)
}