package handler

import (
	"context"
	"net/http"
	"strconv"
	"strings"
	"time"

	"gpt-plus/internal/db"
	"gpt-plus/pkg/provider/card"

	"github.com/gin-gonic/gin"
)

func RegisterCardRoutes(api *gin.RouterGroup) {
	// Cards
	api.GET("/cards", ListCards)
	api.GET("/cards/active", GetActiveCard)
	api.GET("/cards/stats", GetCardStats)
	api.POST("/cards", AddCard)
	api.PUT("/cards/:id/activate", ActivateCard)
	api.PUT("/cards/:id/status", UpdateCardStatus)
	api.DELETE("/cards/:id", DeleteCard)

	// Card codes
	api.GET("/card-codes", ListCardCodes)
	api.GET("/card-codes/stats", GetCardCodeStats)
	api.POST("/card-codes/import", ImportCardCodes)
	api.POST("/card-codes/redeem", RedeemCardCode)
	api.DELETE("/card-codes/:id", DeleteCardCode)
}

func ListCards(c *gin.Context) {
	d := db.GetDB()
	query := d.Model(&db.Card{}).Order("created_at DESC")

	if status := c.Query("status"); status != "" {
		query = query.Where("status = ?", status)
	}

	p := db.PaginationParams{
		Page: intQuery(c, "page", 1),
		Size: intQuery(c, "size", 20),
	}

	var cards []db.Card
	result, err := db.Paginate(query, p, &cards)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}

	for i := range cards {
		number, _ := db.Decrypt(cards[i].NumberEnc)
		cards[i].NumberLast4 = number
		cvc, _ := db.Decrypt(cards[i].CVCEnc)
		cards[i].CVCPlain = cvc
	}
	result.Items = cards
	c.JSON(http.StatusOK, result)
}

func GetActiveCard(c *gin.Context) {
	d := db.GetDB()
	var card db.Card
	if err := d.Where("status = ?", "active").First(&card).Error; err != nil {
		c.JSON(http.StatusNotFound, gin.H{"error": "无激活的卡片"})
		return
	}
	number, _ := db.Decrypt(card.NumberEnc)
	card.NumberLast4 = number
	cvc, _ := db.Decrypt(card.CVCEnc)
	card.CVCPlain = cvc
	c.JSON(http.StatusOK, card)
}

func GetCardStats(c *gin.Context) {
	c.JSON(http.StatusOK, db.GetCardStats(db.GetDB()))
}

type addCardRequest struct {
	Number   string `json:"number" binding:"required"`
	CVC      string `json:"cvc" binding:"required"`
	ExpMonth string `json:"exp_month" binding:"required"`
	ExpYear  string `json:"exp_year" binding:"required"`
	Name     string `json:"name"`
	Country  string `json:"country"`
}

func AddCard(c *gin.Context) {
	var req addCardRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	numberEnc, _ := db.Encrypt(req.Number)
	cvcEnc, _ := db.Encrypt(req.CVC)

	maxBinds := 0 // 0 = unlimited
	var cfg db.SystemConfig
	if db.GetDB().Where("key = ?", "card.max_binds").First(&cfg).Error == nil {
		maxBinds, _ = strconv.Atoi(cfg.Value)
	}

	card := &db.Card{
		NumberHash: db.HashSHA256(req.Number),
		NumberEnc:  numberEnc,
		CVCEnc:     cvcEnc,
		ExpMonth:   req.ExpMonth,
		ExpYear:    req.ExpYear,
		Name:       req.Name,
		Country:    req.Country,
		Source:     "manual",
		Status:     "available",
		MaxBinds:   maxBinds,
	}

	if err := db.GetDB().Create(card).Error; err != nil {
		if strings.Contains(err.Error(), "UNIQUE") {
			c.JSON(http.StatusConflict, gin.H{"error": "该卡号已存在"})
			return
		}
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}
	c.JSON(http.StatusCreated, gin.H{"id": card.ID, "message": "卡片已添加"})
}

func ActivateCard(c *gin.Context) {
	id := c.Param("id")
	d := db.GetDB()

	// Deactivate current active card
	d.Model(&db.Card{}).Where("status = ?", "active").Update("status", "available")

	var card db.Card
	if err := d.First(&card, id).Error; err != nil {
		c.JSON(http.StatusNotFound, gin.H{"error": "卡片不存在"})
		return
	}
	card.Status = "active"
	d.Save(&card)
	c.JSON(http.StatusOK, gin.H{"message": "已激活"})
}

func UpdateCardStatus(c *gin.Context) {
	id := c.Param("id")
	var req struct {
		Status string `json:"status" binding:"required"`
	}
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}
	if req.Status != "disabled" && req.Status != "available" {
		c.JSON(http.StatusBadRequest, gin.H{"error": "状态只能为 disabled 或 available"})
		return
	}
	if err := db.GetDB().Model(&db.Card{}).Where("id = ?", id).Update("status", req.Status).Error; err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}
	c.JSON(http.StatusOK, gin.H{"message": "状态已更新"})
}

func DeleteCard(c *gin.Context) {
	if err := db.GetDB().Delete(&db.Card{}, c.Param("id")).Error; err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}
	c.JSON(http.StatusOK, gin.H{"message": "已删除"})
}

// Card Codes

func ListCardCodes(c *gin.Context) {
	d := db.GetDB()
	query := d.Model(&db.CardCode{}).Order("created_at DESC")
	if status := c.Query("status"); status != "" {
		query = query.Where("status = ?", status)
	}
	p := db.PaginationParams{Page: intQuery(c, "page", 1), Size: intQuery(c, "size", 20)}
	var codes []db.CardCode
	result, err := db.Paginate(query, p, &codes)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}
	c.JSON(http.StatusOK, result)
}

func GetCardCodeStats(c *gin.Context) {
	c.JSON(http.StatusOK, db.GetCardCodeStats(db.GetDB()))
}

func ImportCardCodes(c *gin.Context) {
	var req struct {
		Codes []string `json:"codes" binding:"required"`
	}
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	d := db.GetDB()
	var count int
	for _, code := range req.Codes {
		code = strings.TrimSpace(code)
		if code == "" {
			continue
		}
		cc := &db.CardCode{Code: code, Status: "unused"}
		if d.Create(cc).Error == nil {
			count++
		}
	}
	c.JSON(http.StatusOK, gin.H{"imported": count})
}

func RedeemCardCode(c *gin.Context) {
	var req struct {
		ID uint `json:"id"`
	}
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	d := db.GetDB()
	var code db.CardCode
	if err := d.First(&code, req.ID).Error; err != nil {
		c.JSON(http.StatusNotFound, gin.H{"error": "卡密不存在"})
		return
	}
	if code.Status != "unused" {
		c.JSON(http.StatusBadRequest, gin.H{"error": "该卡密状态不是 unused"})
		return
	}

	code.Status = "redeeming"
	d.Save(&code)

	// Redeem in background
	go func() {
		var cfgBase db.SystemConfig
		apiBase := ""
		if db.GetDB().Where("key = ?", "card.api_base_url").First(&cfgBase).Error == nil {
			apiBase = cfgBase.Value
		}
		if apiBase == "" {
			code.Status = "failed"
			code.Error = "开卡 API 地址未配置"
			d.Save(&code)
			return
		}

		apiProv, err := card.NewAPIProvider(card.APIProviderConfig{
			BaseURL: apiBase,
			Codes:   []string{code.Code},
			PoolCfg: card.PoolConfig{MultiBind: true, MaxBinds: 999},
		})
		if err != nil {
			code.Status = "failed"
			code.Error = err.Error()
			d.Save(&code)
			return
		}

		cardInfo, err := apiProv.GetCard(context.Background())
		if err != nil {
			code.Status = "failed"
			code.Error = err.Error()
			d.Save(&code)
			return
		}

		numberEnc, _ := db.Encrypt(cardInfo.Number)
		cvcEnc, _ := db.Encrypt(cardInfo.CVC)
		newCard := &db.Card{
			NumberHash: db.HashSHA256(cardInfo.Number),
			NumberEnc:  numberEnc,
			CVCEnc:     cvcEnc,
			ExpMonth:   cardInfo.ExpMonth,
			ExpYear:    cardInfo.ExpYear,
			Name:       cardInfo.Name,
			Country:    cardInfo.Country,
			Source:     "api",
			CardCodeID: &code.ID,
			Status:     "available",
			MaxBinds:   1,
		}
		d.Create(newCard)

		now := time.Now()
		code.Status = "redeemed"
		code.CardID = &newCard.ID
		code.RedeemedAt = &now
		d.Save(&code)
	}()

	c.JSON(http.StatusOK, gin.H{"message": "兑换已开始"})
}

func DeleteCardCode(c *gin.Context) {
	if err := db.GetDB().Delete(&db.CardCode{}, c.Param("id")).Error; err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}
	c.JSON(http.StatusOK, gin.H{"message": "已删除"})
}

func intQuery(c *gin.Context, key string, def int) int {
	v := c.Query(key)
	if v == "" {
		return def
	}
	n, err := strconv.Atoi(v)
	if err != nil {
		return def
	}
	return n
}