package api

import (
	"encoding/json"
	"net/http"
	"strconv"
	"time"

	"github.com/gin-gonic/gin"
	"opencatd-open/internal/auth"
	"opencatd-open/internal/pkg/jwt"
	"opencatd-open/internal/store"
)

// PasskeyRegisterBegin POST /api/webauthn/register/begin — 生成注册选项。
func (h *Handler) PasskeyRegisterBegin(c *gin.Context) {
	userID, _ := c.Get("user_id")
	u, err := h.passkeys.GetUserByID(userID.(uint64))
	if err != nil {
		c.JSON(http.StatusUnauthorized, gin.H{"error": "user not found"})
		return
	}
	creation, err := h.passkeys.BeginRegistration(u)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "failed to begin registration: " + err.Error()})
		return
	}
	c.JSON(http.StatusOK, gin.H{"data": gin.H{"creation": creation, "challenge": creation.Response.Challenge}})
}

// PasskeyRegisterComplete POST /api/webauthn/register/complete — 校验并保存凭据。
func (h *Handler) PasskeyRegisterComplete(c *gin.Context) {
	userID, _ := c.Get("user_id")
	u, err := h.passkeys.GetUserByID(userID.(uint64))
	if err != nil {
		c.JSON(http.StatusUnauthorized, gin.H{"error": "user not found"})
		return
	}
	var req struct {
		Challenge  string          `json:"challenge"`
		Name       string          `json:"name"`
		Credential json.RawMessage `json:"credential"`
	}
	if err := c.ShouldBindJSON(&req); err != nil || len(req.Credential) == 0 {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid input"})
		return
	}
	if err := h.passkeys.FinishRegistration(u, req.Challenge, req.Credential, req.Name); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "passkey 注册失败: " + err.Error()})
		return
	}
	c.JSON(http.StatusOK, gin.H{"data": gin.H{"ok": true}})
}

// PasskeyLoginBegin POST /api/auth/passkey/begin — 生成断言选项。
// 传 username 用指定用户；不传则用可发现凭据（平台 passkey）。
func (h *Handler) PasskeyLoginBegin(c *gin.Context) {
	var req struct {
		Username string `json:"username"`
	}
	_ = c.ShouldBindJSON(&req)
	if req.Username != "" {
		u, err := h.passkeys.GetUserByUsername(req.Username)
		if err != nil || u.Status != store.UserStatusActive {
			c.JSON(http.StatusNotFound, gin.H{"error": "user not found"})
			return
		}
		assertion, err := h.passkeys.BeginLogin(u)
		if err != nil {
			c.JSON(http.StatusInternalServerError, gin.H{"error": "failed to begin login: " + err.Error()})
			return
		}
		c.JSON(http.StatusOK, gin.H{"data": gin.H{"assertion": assertion, "challenge": assertion.Response.Challenge, "user_id": u.ID}})
		return
	}
	assertion, err := h.passkeys.BeginDiscoverableLogin()
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "failed to begin login: " + err.Error()})
		return
	}
	c.JSON(http.StatusOK, gin.H{"data": gin.H{"assertion": assertion, "challenge": assertion.Response.Challenge}})
}

// PasskeyLoginComplete POST /api/auth/passkey/finish — 校验断言并发放令牌。
func (h *Handler) PasskeyLoginComplete(c *gin.Context) {
	var req struct {
		Challenge  string          `json:"challenge"`
		Credential json.RawMessage `json:"credential"`
		UserID     uint64          `json:"user_id"`
	}
	if err := c.ShouldBindJSON(&req); err != nil || len(req.Credential) == 0 {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid input"})
		return
	}
	var u *store.User
	if req.UserID > 0 {
		var err error
		u, err = h.passkeys.GetUserByID(req.UserID)
		if err != nil {
			c.JSON(http.StatusUnauthorized, gin.H{"error": "user not found"})
			return
		}
		if err := h.passkeys.FinishLogin(u, req.Challenge, req.Credential); err != nil {
			c.JSON(http.StatusUnauthorized, gin.H{"error": "passkey 校验失败: " + err.Error()})
			return
		}
	} else {
		var err error
		u, err = h.passkeys.FinishDiscoverableLogin(req.Challenge, req.Credential)
		if err != nil {
			c.JSON(http.StatusUnauthorized, gin.H{"error": "passkey 校验失败: " + err.Error()})
			return
		}
	}
	if u.Status != store.UserStatusActive {
		c.JSON(http.StatusForbidden, gin.H{"error": "user account disabled"})
		return
	}
	secret := auth.GetSecretKey()
	accessToken, refreshToken, err := jwt.GenerateTokenPair(u.ID, u.Username, u.Role, secret, 24*time.Hour, 7*24*time.Hour)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "failed to issue token"})
		return
	}
	c.JSON(http.StatusOK, gin.H{
		"data": gin.H{
			"token":        accessToken,
			"access_token":  accessToken,
			"refresh_token": refreshToken,
		},
	})
}

// PasskeyList GET /api/profile/passkeys — 当前用户的 passkey 列表。
func (h *Handler) PasskeyList(c *gin.Context) {
	userID, _ := c.Get("user_id")
	pks, err := h.passkeys.List(userID.(uint64))
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "failed to load passkeys"})
		return
	}
	out := make([]gin.H, 0, len(pks))
	for _, pk := range pks {
		out = append(out, gin.H{"id": pk.ID, "name": pk.Name, "created_at": pk.CreatedAt})
	}
	c.JSON(http.StatusOK, gin.H{"data": out})
}

// PasskeyDelete DELETE /api/profile/passkeys/:id — 解除绑定。
func (h *Handler) PasskeyDelete(c *gin.Context) {
	userID, _ := c.Get("user_id")
	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid passkey id"})
		return
	}
	if err := h.passkeys.Delete(userID.(uint64), id); err != nil {
		c.JSON(http.StatusNotFound, gin.H{"error": "passkey not found"})
		return
	}
	c.JSON(http.StatusOK, gin.H{"data": gin.H{"ok": true}})
}