package handler

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

	"github.com/freefire/jiang13-bbs/middleware"
	"github.com/freefire/jiang13-bbs/model"
	"github.com/freefire/jiang13-bbs/service"
	"github.com/gin-gonic/gin"
)

// snippetError 统一错误映射
func snippetError(c *gin.Context, err error) {
	switch {
	case errors.Is(err, service.ErrSnippetNotFound):
		c.JSON(http.StatusNotFound, gin.H{"error": "代码片段不存在"})
	case errors.Is(err, service.ErrSnippetForbidden):
		c.JSON(http.StatusForbidden, gin.H{"error": "无权操作该代码片段"})
	case errors.Is(err, service.ErrSnippetBadInput):
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
	case errors.Is(err, service.ErrCommentNotFound):
		c.JSON(http.StatusNotFound, gin.H{"error": "评论不存在"})
	case errors.Is(err, service.ErrCommentForbidden):
		c.JSON(http.StatusForbidden, gin.H{"error": "无权操作该评论"})
	default:
		c.JSON(http.StatusInternalServerError, gin.H{"error": "服务器错误"})
	}
}

// SnippetList 公开片段广场
func (h *Handlers) SnippetList(c *gin.Context) {
	q := c.Query("q")
	lang := c.Query("lang")
	sort := c.Query("sort")
	page, _ := strconv.Atoi(c.DefaultQuery("page", "1"))
	size, _ := strconv.Atoi(c.DefaultQuery("size", "12"))
	items, total, err := h.SnippetSvc.ListPublic(q, lang, sort, page, size)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "获取片段列表失败"})
		return
	}
	c.JSON(http.StatusOK, gin.H{"items": nonNilSlice(items), "total": total})
}

// SnippetLanguages 语言白名单
func (h *Handlers) SnippetLanguages(c *gin.Context) {
	c.JSON(http.StatusOK, gin.H{"languages": service.SnippetLanguages()})
}

// SnippetStats 广场聚合统计
func (h *Handlers) SnippetStats(c *gin.Context) {
	stats, err := h.SnippetSvc.Stats()
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "获取统计失败"})
		return
	}
	c.JSON(http.StatusOK, gin.H{"stats": stats})
}

// SnippetDetail 公开片段详情
func (h *Handlers) SnippetDetail(c *gin.Context) {
	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "无效的片段 ID"})
		return
	}
	var viewerID uint
	if claims := middleware.CurrentUser(c); claims != nil {
		viewerID = claims.ID
	}
	isStaff := h.isStaff(c)
	detail, err := h.SnippetSvc.GetPublic(uint(id), viewerID, isStaff)
	if err != nil {
		snippetError(c, err)
		return
	}
	c.JSON(http.StatusOK, gin.H{"snippet": detail})
}

// SnippetMine 我的片段列表
func (h *Handlers) SnippetMine(c *gin.Context) {
	claims := middleware.CurrentUser(c)
	if claims == nil {
		c.JSON(http.StatusUnauthorized, gin.H{"error": "请先登录"})
		return
	}
	q := c.Query("q")
	page, _ := strconv.Atoi(c.DefaultQuery("page", "1"))
	size, _ := strconv.Atoi(c.DefaultQuery("size", "12"))
	items, total, err := h.SnippetSvc.ListMine(claims.ID, q, page, size)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "获取片段列表失败"})
		return
	}
	c.JSON(http.StatusOK, gin.H{"items": nonNilSlice(items), "total": total})
}

// SnippetCreate 创建片段
func (h *Handlers) SnippetCreate(c *gin.Context) {
	claims := middleware.CurrentUser(c)
	if claims == nil {
		c.JSON(http.StatusUnauthorized, gin.H{"error": "请先登录"})
		return
	}
	var in service.SnippetInput
	if err := c.ShouldBindJSON(&in); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "请求参数无效"})
		return
	}
	snippet, err := h.SnippetSvc.Create(&in, claims.ID)
	if err != nil {
		snippetError(c, err)
		return
	}
	c.JSON(http.StatusCreated, gin.H{"snippet": snippet})
}

// SnippetUpdate 更新片段
func (h *Handlers) SnippetUpdate(c *gin.Context) {
	claims := middleware.CurrentUser(c)
	if claims == nil {
		c.JSON(http.StatusUnauthorized, gin.H{"error": "请先登录"})
		return
	}
	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "无效的片段 ID"})
		return
	}
	var in service.SnippetInput
	if err := c.ShouldBindJSON(&in); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "请求参数无效"})
		return
	}
	snippet, err := h.SnippetSvc.Update(uint(id), &in, claims.ID, h.isStaff(c))
	if err != nil {
		snippetError(c, err)
		return
	}
	c.JSON(http.StatusOK, gin.H{"snippet": snippet})
}

// SnippetDelete 删除片段（owner 或 staff）
func (h *Handlers) SnippetDelete(c *gin.Context) {
	claims := middleware.CurrentUser(c)
	if claims == nil {
		c.JSON(http.StatusUnauthorized, gin.H{"error": "请先登录"})
		return
	}
	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "无效的片段 ID"})
		return
	}
	if err := h.SnippetSvc.Delete(uint(id), claims.ID, h.isStaff(c)); err != nil {
		snippetError(c, err)
		return
	}
	c.JSON(http.StatusOK, gin.H{"ok": true})
}

// SnippetFork Fork 公开片段
func (h *Handlers) SnippetFork(c *gin.Context) {
	claims := middleware.CurrentUser(c)
	if claims == nil {
		c.JSON(http.StatusUnauthorized, gin.H{"error": "请先登录"})
		return
	}
	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "无效的片段 ID"})
		return
	}
	snippet, err := h.SnippetSvc.Fork(uint(id), claims.ID)
	if err != nil {
		snippetError(c, err)
		return
	}
	c.JSON(http.StatusCreated, gin.H{"snippet": snippet})
}

// SnippetCopy 记录复制（节流由 service 内部处理）
func (h *Handlers) SnippetCopy(c *gin.Context) {
	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "无效的片段 ID"})
		return
	}
	key := c.ClientIP()
	if claims := middleware.CurrentUser(c); claims != nil {
		key = "user:" + strconv.FormatUint(uint64(claims.ID), 10)
	}
	if err := h.SnippetSvc.RecordCopy(uint(id), key); err != nil {
		snippetError(c, err)
		return
	}
	c.JSON(http.StatusOK, gin.H{"ok": true})
}

// SnippetHistory 片段编辑历史
func (h *Handlers) SnippetHistory(c *gin.Context) {
	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "无效的片段 ID"})
		return
	}
	page, _ := strconv.Atoi(c.DefaultQuery("page", "1"))
	size, _ := strconv.Atoi(c.DefaultQuery("size", "10"))
	items, total, err := h.SnippetSvc.ListHistory(uint(id), page, size)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "获取历史失败"})
		return
	}
	c.JSON(http.StatusOK, gin.H{"items": nonNilSlice(items), "total": total})
}

// SnippetForks 公开 fork 列表
func (h *Handlers) SnippetForks(c *gin.Context) {
	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "无效的片段 ID"})
		return
	}
	page, _ := strconv.Atoi(c.DefaultQuery("page", "1"))
	size, _ := strconv.Atoi(c.DefaultQuery("size", "12"))
	items, total, err := h.SnippetSvc.ListForks(uint(id), page, size)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "获取 Fork 列表失败"})
		return
	}
	c.JSON(http.StatusOK, gin.H{"items": nonNilSlice(items), "total": total})
}

// SnippetComments 片段评论列表
func (h *Handlers) SnippetComments(c *gin.Context) {
	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "无效的片段 ID"})
		return
	}
	page, _ := strconv.Atoi(c.DefaultQuery("page", "1"))
	size, _ := strconv.Atoi(c.DefaultQuery("size", "20"))
	items, total, err := h.SnippetSvc.ListComments(uint(id), page, size)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "获取评论失败"})
		return
	}
	c.JSON(http.StatusOK, gin.H{"items": nonNilSlice(items), "total": total})
}

// SnippetCommentCreate 创建片段评论
func (h *Handlers) SnippetCommentCreate(c *gin.Context) {
	claims := middleware.CurrentUser(c)
	if claims == nil {
		c.JSON(http.StatusUnauthorized, gin.H{"error": "请先登录"})
		return
	}
	snippetID, err := strconv.ParseUint(c.Param("id"), 10, 64)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "无效的片段 ID"})
		return
	}
	var in struct {
		Content  string `json:"content"`
		ParentID *uint  `json:"parent_id"`
	}
	if err := c.ShouldBindJSON(&in); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "请求参数无效"})
		return
	}
	comment, err := h.SnippetSvc.CreateComment(claims.ID, uint(snippetID), in.Content, in.ParentID)
	if err != nil {
		snippetError(c, err)
		return
	}
	c.JSON(http.StatusCreated, gin.H{"comment": comment})
}

// SnippetCommentUpdate 更新片段评论
func (h *Handlers) SnippetCommentUpdate(c *gin.Context) {
	claims := middleware.CurrentUser(c)
	if claims == nil {
		c.JSON(http.StatusUnauthorized, gin.H{"error": "请先登录"})
		return
	}
	cid, err := strconv.ParseUint(c.Param("cid"), 10, 64)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "无效的评论 ID"})
		return
	}
	var in struct {
		Content string `json:"content"`
	}
	if err := c.ShouldBindJSON(&in); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "请求参数无效"})
		return
	}
	comment, err := h.SnippetSvc.UpdateComment(uint(cid), claims.ID, in.Content)
	if err != nil {
		snippetError(c, err)
		return
	}
	c.JSON(http.StatusOK, gin.H{"comment": comment})
}

// SnippetCommentDelete 删除片段评论
func (h *Handlers) SnippetCommentDelete(c *gin.Context) {
	claims := middleware.CurrentUser(c)
	if claims == nil {
		c.JSON(http.StatusUnauthorized, gin.H{"error": "请先登录"})
		return
	}
	cid, err := strconv.ParseUint(c.Param("cid"), 10, 64)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "无效的评论 ID"})
		return
	}
	if err := h.SnippetSvc.DeleteComment(uint(cid), claims.ID, h.isStaff(c)); err != nil {
		snippetError(c, err)
		return
	}
	c.JSON(http.StatusOK, gin.H{"ok": true})
}

// SnippetCommentHistory 片段评论编辑历史（登录即可见；分页）
func (h *Handlers) SnippetCommentHistory(c *gin.Context) {
	claims := middleware.CurrentUser(c)
	cid, err := strconv.ParseUint(c.Param("cid"), 10, 64)
	if err != nil || cid == 0 {
		c.JSON(http.StatusBadRequest, gin.H{"error": "无效的评论 ID"})
		return
	}
	page, _ := strconv.Atoi(c.DefaultQuery("page", "1"))
	size, _ := strconv.Atoi(c.DefaultQuery("size", "10"))
	items, total, err := h.SnippetSvc.ListCommentHistory(h.loadActor(claims.ID), uint(cid), page, size)
	if err != nil {
		switch {
		case errors.Is(err, service.ErrCommentNotFound):
			c.JSON(http.StatusNotFound, gin.H{"error": err.Error()})
		case errors.Is(err, service.ErrCommentForbidden):
			c.JSON(http.StatusForbidden, gin.H{"error": err.Error()})
		default:
			c.JSON(http.StatusInternalServerError, gin.H{"error": "获取编辑历史失败"})
		}
		return
	}
	if page < 1 {
		page = 1
	}
	if size < 1 || size > 50 {
		size = 10
	}
	c.JSON(http.StatusOK, gin.H{
		"items": items,
		"total": total,
		"page":  page,
		"size":  size,
	})
}

// AdminSnippetList 管理端片段列表
func (h *Handlers) AdminSnippetList(c *gin.Context) {
	q := c.Query("q")
	visibility := c.Query("visibility")
	page, _ := strconv.Atoi(c.DefaultQuery("page", "1"))
	size, _ := strconv.Atoi(c.DefaultQuery("size", "20"))
	items, total, err := h.SnippetSvc.AdminList(q, visibility, page, size)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "获取片段列表失败"})
		return
	}
	c.JSON(http.StatusOK, gin.H{"items": nonNilSlice(items), "total": total})
}

// AdminSnippetDelete 管理端软删片段
func (h *Handlers) AdminSnippetDelete(c *gin.Context) {
	claims := middleware.CurrentUser(c)
	if claims == nil {
		c.JSON(http.StatusUnauthorized, gin.H{"error": "请先登录"})
		return
	}
	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "无效的片段 ID"})
		return
	}
	if err := h.SnippetSvc.AdminDelete(uint(id), claims.ID); err != nil {
		snippetError(c, err)
		return
	}
	c.JSON(http.StatusOK, gin.H{"ok": true})
}

// AdminSnippetSetVisibility 管理端强制修改可见性
func (h *Handlers) AdminSnippetSetVisibility(c *gin.Context) {
	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "无效的片段 ID"})
		return
	}
	var in struct {
		Visibility string `json:"visibility"`
	}
	if err := c.ShouldBindJSON(&in); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "请求参数无效"})
		return
	}
	if err := h.SnippetSvc.AdminSetVisibility(uint(id), in.Visibility); err != nil {
		snippetError(c, err)
		return
	}
	c.JSON(http.StatusOK, gin.H{"ok": true})
}

// isStaff 判断当前用户是否为管理角色
func (h *Handlers) isStaff(c *gin.Context) bool {
	claims := middleware.CurrentUser(c)
	if claims == nil {
		return false
	}
	return model.IsStaff(model.Role(claims.Role))
}