package api

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

	"github.com/gin-gonic/gin"

	"gorm.io/gorm"

	"oci-portal/internal/service"
)

// sessionHandler 处理活跃会话查看与定点撤销接口。
type sessionHandler struct {
	auth *service.AuthService
}

// bearerToken 取 Authorization 头中的原始令牌串;不存在返回空串。
func bearerToken(c *gin.Context) string {
	token, ok := strings.CutPrefix(c.GetHeader("Authorization"), "Bearer ")
	if !ok {
		return ""
	}
	return token
}

// sessionMetaOf 采集会话登记所需的客户端上下文;登录方式由 service 层填写。
func sessionMetaOf(c *gin.Context) service.SessionMeta {
	return service.SessionMeta{
		ClientIP:  requestIP(c),
		UserAgent: truncateLogField(c.Request.UserAgent(), 256),
	}
}

// list 列出当前账号的活跃会话,最近活跃在前,当前会话带 current 标记。
//
// @Summary  活跃会话列表
// @Tags     认证
// @Success  200 {object} itemsResponse[service.SessionInfo] "items"
// @Security BearerAuth
// @Router   /api/v1/auth/sessions [get]
func (h *sessionHandler) list(c *gin.Context) {
	items, err := h.auth.ListSessions(c.Request.Context(), c.GetString(usernameKey), bearerToken(c))
	if err != nil {
		respondError(c, err)
		return
	}
	c.JSON(http.StatusOK, gin.H{"items": items})
}

// revoke 定点撤销一个其他会话;该会话令牌随即失效,不影响其余会话。
//
// @Summary  撤销单个会话
// @Tags     认证
// @Param    id path int true "会话 ID"
// @Success  204 "已撤销"
// @Failure  400 {object} errorResponse "id 非法"
// @Failure  404 {object} errorResponse "会话不存在"
// @Failure  409 {object} errorResponse "不能撤销当前会话"
// @Security BearerAuth
// @Router   /api/v1/auth/sessions/{id} [delete]
func (h *sessionHandler) revoke(c *gin.Context) {
	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid id"})
		return
	}
	err = h.auth.RevokeSession(c.Request.Context(), c.GetString(usernameKey), bearerToken(c), uint(id))
	if errors.Is(err, service.ErrSessionCurrent) {
		c.JSON(http.StatusConflict, gin.H{"error": err.Error()})
		return
	}
	if errors.Is(err, gorm.ErrRecordNotFound) {
		c.JSON(http.StatusNotFound, gin.H{"error": "会话不存在或已失效"})
		return
	}
	if err != nil {
		respondError(c, err)
		return
	}
	c.Status(http.StatusNoContent)
}