package handler

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

	"bj_power_mes/common/httpx"
	tokenx "bj_power_mes/common/token"
	"bj_power_mes/internal/logic"
	"bj_power_mes/internal/svc"

	"github.com/zeromicro/go-zero/rest/pathvar"
)

// ctxUserId 从 JWT 上下文取用户ID（go-zero 将自定义 claim 放入 context）
func ctxUserId(r *http.Request) int {
	switch v := r.Context().Value("userId").(type) {
	case float64:
		return int(v)
	case int:
		return v
	case int64:
		return int(v)
	case string:
		n, _ := strconv.Atoi(v)
		return n
	}
	return 0
}

// uidFromRequest 取当前登录用户ID：优先 context，缺失时回退解析 Authorization Bearer token（更稳健）
func uidFromRequest(r *http.Request, svcCtx *svc.ServiceContext) int {
	if uid := ctxUserId(r); uid > 0 {
		return uid
	}
	auth := strings.TrimPrefix(r.Header.Get("Authorization"), "Bearer ")
	if auth == "" || auth == r.Header.Get("Authorization") {
		return 0
	}
	claims, err := tokenx.Parse(svcCtx.Config.Auth.AccessSecret, auth)
	if err == nil && claims.UserId > 0 {
		return claims.UserId
	}
	return 0
}

// ctxOperator 当前操作人：优先取 name，其次 username
func ctxOperator(r *http.Request) string {
	if v, ok := r.Context().Value("name").(string); ok && v != "" {
		return v
	}
	if v, ok := r.Context().Value("username").(string); ok && v != "" {
		return v
	}
	return "system"
}

// pathId 读取路由参数 :id
func pathId(r *http.Request) int {
	vars := pathvar.Vars(r)
	if vars == nil {
		return 0
	}
	n, _ := strconv.Atoi(vars["id"])
	return n
}

func LoginHandler(svcCtx *svc.ServiceContext) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		var req logic.LoginReq
		if err := httpx.ParseJSON(r, &req); err != nil {
			httpx.BadRequest(w, "请求体解析失败")
			return
		}
		data, err := logic.New(svcCtx).Login(r.Context(), req)
		if err != nil {
			httpx.Fail(w, 1001, err.Error())
			return
		}
		// 操作日志：登录成功（写失败不阻断登录）
		svcCtx.EventLog.Write(r.Context(), "auth.login", "", req.Username, "auth", req.Username,
			"登录成功", map[string]any{"ip": clientIP(r)})
		httpx.Ok(w, data)
	}
}

// clientIP 取客户端 IP（优先代理头，兜底 RemoteAddr）
func clientIP(r *http.Request) string {
	if v := r.Header.Get("X-Real-IP"); v != "" {
		return v
	}
	if v := r.Header.Get("X-Forwarded-For"); v != "" {
		for i := 0; i < len(v); i++ {
			if v[i] == ',' {
				return strings.TrimSpace(v[:i])
			}
		}
		return strings.TrimSpace(v)
	}
	if host := r.RemoteAddr; host != "" {
		if i := strings.LastIndex(host, ":"); i > 0 {
			return host[:i]
		}
		return host
	}
	return ""
}

// LogoutHandler POST /api/v1/logout 退出登录（需登录 JWT）
// 记录退出日志；登录态清除由前端完成（无状态 JWT 无服务端会话）。
func LogoutHandler(svcCtx *svc.ServiceContext) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		username, _ := r.Context().Value("username").(string)
		if username == "" {
			if u, err := svcCtx.EntClient.User.Get(r.Context(), uidFromRequest(r, svcCtx)); err == nil {
				username = u.Username
			}
		}
		if username != "" {
			svcCtx.EventLog.Write(r.Context(), "auth.logout", "", username, "auth", username,
				"退出登录", map[string]any{"ip": clientIP(r)})
		}
		httpx.OkMessage(w, "已退出", nil)
	}
}

func UserInfoHandler(svcCtx *svc.ServiceContext) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		data, err := logic.New(svcCtx).UserInfo(r.Context(), uidFromRequest(r, svcCtx))
		if err != nil {
			httpx.Fail(w, 1003, err.Error())
			return
		}
		httpx.Ok(w, data)
	}
}

func SeedHandler(svcCtx *svc.ServiceContext) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		if err := logic.New(svcCtx).Seed(r.Context()); err != nil {
			httpx.Fail(w, 1004, err.Error())
			return
		}
		httpx.OkMessage(w, "初始化完成", nil)
	}
}

// ---------- 用户管理 ----------

func ListUsersHandler(svcCtx *svc.ServiceContext) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		data, err := logic.New(svcCtx).ListUsers(r.Context())
		if err != nil {
			httpx.Fail(w, 1005, err.Error())
			return
		}
		httpx.Ok(w, data)
	}
}

func CreateUserHandler(svcCtx *svc.ServiceContext) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		var req logic.UserReq
		if err := httpx.ParseJSON(r, &req); err != nil {
			httpx.BadRequest(w, "请求体解析失败")
			return
		}
		if err := logic.New(svcCtx).CreateUser(r.Context(), req); err != nil {
			httpx.Fail(w, 1006, err.Error())
			return
		}
		httpx.OkMessage(w, "创建成功", nil)
	}
}

func UpdateUserHandler(svcCtx *svc.ServiceContext) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		var req logic.UserReq
		if err := httpx.ParseJSON(r, &req); err != nil {
			httpx.BadRequest(w, "请求体解析失败")
			return
		}
		if err := logic.New(svcCtx).UpdateUser(r.Context(), req); err != nil {
			httpx.Fail(w, 1007, err.Error())
			return
		}
		httpx.OkMessage(w, "更新成功", nil)
	}
}

func DeleteUserHandler(svcCtx *svc.ServiceContext) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		if err := logic.New(svcCtx).DeleteUser(r.Context(), pathId(r)); err != nil {
			httpx.Fail(w, 1008, err.Error())
			return
		}
		httpx.OkMessage(w, "删除成功", nil)
	}
}

// ---------- 修改自己的密码 ----------

func ChangePasswordHandler(svcCtx *svc.ServiceContext) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		var req logic.ChangePasswordReq
		if err := httpx.ParseJSON(r, &req); err != nil {
			httpx.BadRequest(w, "请求体解析失败")
			return
		}
		if err := logic.New(svcCtx).ChangePassword(r.Context(), uidFromRequest(r, svcCtx), req); err != nil {
			httpx.Fail(w, 1017, err.Error())
			return
		}
		httpx.OkMessage(w, "密码修改成功", nil)
	}
}

// ---------- 角色管理 ----------

func ListRolesHandler(svcCtx *svc.ServiceContext) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		data, err := logic.New(svcCtx).ListRoles(r.Context())
		if err != nil {
			httpx.Fail(w, 1009, err.Error())
			return
		}
		httpx.Ok(w, data)
	}
}

func CreateRoleHandler(svcCtx *svc.ServiceContext) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		var req logic.RoleReq
		if err := httpx.ParseJSON(r, &req); err != nil {
			httpx.BadRequest(w, "请求体解析失败")
			return
		}
		if err := logic.New(svcCtx).CreateRole(r.Context(), req); err != nil {
			httpx.Fail(w, 1010, err.Error())
			return
		}
		httpx.OkMessage(w, "创建成功", nil)
	}
}

func UpdateRoleHandler(svcCtx *svc.ServiceContext) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		var req logic.RoleReq
		if err := httpx.ParseJSON(r, &req); err != nil {
			httpx.BadRequest(w, "请求体解析失败")
			return
		}
		if err := logic.New(svcCtx).UpdateRole(r.Context(), req); err != nil {
			httpx.Fail(w, 1011, err.Error())
			return
		}
		httpx.OkMessage(w, "更新成功", nil)
	}
}

func DeleteRoleHandler(svcCtx *svc.ServiceContext) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		if err := logic.New(svcCtx).DeleteRole(r.Context(), pathId(r)); err != nil {
			httpx.Fail(w, 1012, err.Error())
			return
		}
		httpx.OkMessage(w, "删除成功", nil)
	}
}

// ---------- 权限管理 ----------

func ListPermissionsHandler(svcCtx *svc.ServiceContext) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		data, err := logic.New(svcCtx).ListPermissions(r.Context())
		if err != nil {
			httpx.Fail(w, 1013, err.Error())
			return
		}
		httpx.Ok(w, data)
	}
}

func CreatePermissionHandler(svcCtx *svc.ServiceContext) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		var req logic.PermissionReq
		if err := httpx.ParseJSON(r, &req); err != nil {
			httpx.BadRequest(w, "请求体解析失败")
			return
		}
		if err := logic.New(svcCtx).CreatePermission(r.Context(), req); err != nil {
			httpx.Fail(w, 1014, err.Error())
			return
		}
		httpx.OkMessage(w, "创建成功", nil)
	}
}

func UpdatePermissionHandler(svcCtx *svc.ServiceContext) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		var req logic.PermissionReq
		if err := httpx.ParseJSON(r, &req); err != nil {
			httpx.BadRequest(w, "请求体解析失败")
			return
		}
		if err := logic.New(svcCtx).UpdatePermission(r.Context(), req); err != nil {
			httpx.Fail(w, 1015, err.Error())
			return
		}
		httpx.OkMessage(w, "更新成功", nil)
	}
}

func DeletePermissionHandler(svcCtx *svc.ServiceContext) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		if err := logic.New(svcCtx).DeletePermission(r.Context(), pathId(r)); err != nil {
			httpx.Fail(w, 1016, err.Error())
			return
		}
		httpx.OkMessage(w, "删除成功", nil)
	}
}