package api

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

	"github.com/gin-gonic/gin"
	"github.com/openteam/server/internal/pkg/resp"
	"github.com/openteam/server/internal/store"
)

// PasskeyRegisterBegin POST /api/v1/webauthn/register/begin — 生成注册选项。
func (h *Handler) PasskeyRegisterBegin(c *gin.Context) {
	u := sessionUser(c)
	creation, err := h.passkeys.BeginRegistration(u)
	if err != nil {
		resp.Fail(c, http.StatusInternalServerError, "failed to begin registration: "+err.Error())
		return
	}
	resp.OK(c, gin.H{"creation": creation, "challenge": creation.Response.Challenge})
}

// PasskeyRegisterComplete POST /api/v1/webauthn/register/complete — 校验并保存凭据。
func (h *Handler) PasskeyRegisterComplete(c *gin.Context) {
	u := sessionUser(c)
	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 {
		resp.Fail(c, http.StatusBadRequest, "invalid input")
		return
	}
	if err := h.passkeys.FinishRegistration(u, req.Challenge, req.Credential, []byte(req.Name)); err != nil {
		resp.Fail(c, http.StatusBadRequest, "passkey 注册失败: "+err.Error())
		return
	}
	resp.OK(c, gin.H{"ok": true})
}

// PasskeyLoginBegin POST /api/v1/webauthn/login/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 != "" {
		var u store.User
		err := h.a.DB.Where("username = ? OR email = ?", req.Username, req.Username).First(&u).Error
		if err != nil || u.Status != store.UserStatusActive {
			resp.Fail(c, http.StatusNotFound, "user not found")
			return
		}
		assertion, err := h.passkeys.BeginLogin(&u)
		if err != nil {
			resp.Fail(c, http.StatusInternalServerError, "failed to begin login: "+err.Error())
			return
		}
		resp.OK(c, gin.H{"assertion": assertion, "challenge": assertion.Response.Challenge, "user_id": u.ID})
		return
	}
	assertion, err := h.passkeys.BeginDiscoverableLogin()
	if err != nil {
		resp.Fail(c, http.StatusInternalServerError, "failed to begin login: "+err.Error())
		return
	}
	resp.OK(c, gin.H{"assertion": assertion, "challenge": assertion.Response.Challenge})
}

// PasskeyLoginComplete POST /api/v1/webauthn/login/complete — 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 {
		resp.Fail(c, http.StatusBadRequest, "invalid input")
		return
	}
	var u *store.User
	if req.UserID > 0 {
		var su store.User
		if err := h.a.DB.First(&su, req.UserID).Error; err != nil {
			resp.Fail(c, http.StatusUnauthorized, "user not found")
			return
		}
		u = &su
		if err := h.passkeys.FinishLogin(u, req.Challenge, req.Credential); err != nil {
			resp.Fail(c, http.StatusUnauthorized, "passkey 校验失败: "+err.Error())
			return
		}
	} else {
		var err error
		u, err = h.passkeys.FinishDiscoverableLogin(req.Challenge, req.Credential)
		if err != nil {
			resp.Fail(c, http.StatusUnauthorized, "passkey 校验失败: "+err.Error())
			return
		}
	}
	if u.Status != store.UserStatusActive {
		resp.Fail(c, http.StatusForbidden, "user account disabled")
		return
	}
	access, _, err := h.a.JWT.Sign(u.ID, u.Username, u.Role, "access")
	if err != nil {
		resp.Fail(c, http.StatusInternalServerError, "failed to issue token")
		return
	}
	refresh, _, err := h.a.JWT.Sign(u.ID, u.Username, u.Role, "refresh")
	if err != nil {
		resp.Fail(c, http.StatusInternalServerError, "failed to issue token")
		return
	}
	h.setRefreshCookie(c, refresh)
	resp.OK(c, gin.H{
		"access_token": access,
		"expires_in":   int(h.a.JWT.AccessTTL().Seconds()),
		"user":         h.publicUser(u),
	})
}

// PasskeyList GET /api/v1/webauthn/passkeys — 当前用户的 passkey 列表。
func (h *Handler) PasskeyList(c *gin.Context) {
	u := sessionUser(c)
	pks, err := h.passkeys.List(u.ID)
	if err != nil {
		resp.Fail(c, http.StatusInternalServerError, "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})
	}
	resp.OK(c, gin.H{"items": out})
}

// PasskeyDelete DELETE /api/v1/webauthn/passkeys/:id — 解除绑定。
func (h *Handler) PasskeyDelete(c *gin.Context) {
	u := sessionUser(c)
	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
	if err != nil {
		resp.Fail(c, http.StatusBadRequest, "invalid passkey id")
		return
	}
	if err := h.passkeys.Delete(u.ID, id); err != nil {
		resp.Fail(c, http.StatusNotFound, "passkey not found")
		return
	}
	resp.OK(c, gin.H{"ok": true})
}