mce/internal/controller/post_controller.go

package controller

import (
	"errors"
	"fmt"
	"mime/multipart"
	"net/http"
	"os"
	"path/filepath"
	"strconv"
	"strings"
	"time"

	"metazone.cc/metalab/internal/common"
	"metazone.cc/metalab/internal/model"
	"metazone.cc/metalab/internal/service"

	"github.com/gin-gonic/gin"
)

// PostController 帖子控制器（SSR 页面 + API）
type PostController struct {
	postService  postUseCase
	shortcodeSvc *service.ShortcodeService
}

// NewPostController 构造函数
func NewPostController(ps postUseCase, scs *service.ShortcodeService) *PostController {
	return &PostController{postService: ps, shortcodeSvc: scs}
}

// ListPage 帖子列表页
func (ctrl *PostController) ListPage(c *gin.Context) {
	keyword := c.Query("keyword")
	page, _ := strconv.Atoi(c.DefaultQuery("page", "1"))
	pageSize, _ := strconv.Atoi(c.DefaultQuery("page_size", "20"))

	posts, total, err := ctrl.postService.List(keyword, page, pageSize)
	if err != nil {
		c.HTML(http.StatusOK, "posts/index.html", common.BuildPageData(c, gin.H{
			"Title": "社区帖子",
			"Error": "加载帖子列表失败",
		}))
		return
	}

	if posts == nil {
		posts = []model.Post{}
	}

	p := common.Pagination{Page: page, PageSize: pageSize}
	p.DefaultPagination()
	totalPages := p.TotalPages(total)

	c.HTML(http.StatusOK, "posts/index.html", common.BuildPageData(c, gin.H{
		"Title":      "社区帖子",
		"Posts":      posts,
		"Total":      total,
		"Page":       p.Page,
		"TotalPages": totalPages,
		"PrevPage":   p.PrevPage(),
		"NextPage":   p.NextPage(totalPages),
		"Keyword":    keyword,
		"ExtraCSS":   "/static/css/posts.css",
	}))
}

// ShowPage 帖子详情页
func (ctrl *PostController) ShowPage(c *gin.Context) {
	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
	if err != nil {
		c.HTML(http.StatusNotFound, "posts/404.html", common.BuildPageData(c, gin.H{
			"Title": "未找到",
		}))
		return
	}

	post, err := ctrl.postService.GetByID(uint(id))
	if err != nil {
		c.HTML(http.StatusNotFound, "posts/404.html", common.BuildPageData(c, gin.H{
			"Title": "未找到",
		}))
		return
	}

	// 获取当前用户信息
	var uid uint
	var role string
	if uidObj, exists := c.Get("uid"); exists {
		uid, _ = uidObj.(uint)
	}
	if roleObj, exists := c.Get("role"); exists {
		role, _ = roleObj.(string)
	}

	// 仅 approved 公开可见（作者本人 + moderator+ 可预览其他状态）
	if post.Status != model.PostStatusApproved {
		isAuthor := uid == post.UserID
		isModerator := model.HasMinRole(role, model.RoleModerator)

		if !isAuthor && !isModerator {
			c.HTML(http.StatusNotFound, "posts/404.html", common.BuildPageData(c, gin.H{
				"Title": "未找到",
			}))
			return
		}
	}

	// 处理 shortcode：[zone:type:params] → HTML 占位符
	// 占位 div 会被 Vditor.preview() 保留，由前端 shortcode.js 渲染为卡片
	if ctrl.shortcodeSvc != nil {
		result := ctrl.shortcodeSvc.Process(post.Body)
		post.Body = result.ProcessedBody
	}

	c.HTML(http.StatusOK, "posts/show.html", common.BuildPageData(c, gin.H{
		"Title":       post.Title,
		"Post":        post,
		"UID":         uid,
		"StatusNames": model.PostStatusDisplayNames,
		"ExtraCSS":    "/static/css/posts.css",
	}))
}

// NewPage 发帖页面
func (ctrl *PostController) NewPage(c *gin.Context) {
	c.HTML(http.StatusOK, "posts/new.html", common.BuildPageData(c, gin.H{
		"Title":    "撰写帖子",
		"ExtraCSS": "/static/css/posts.css",
	}))
}

// EditPage 编辑页面
func (ctrl *PostController) EditPage(c *gin.Context) {
	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
	if err != nil {
		c.HTML(http.StatusNotFound, "posts/404.html", common.BuildPageData(c, gin.H{
			"Title": "未找到",
		}))
		return
	}

	post, err := ctrl.postService.GetByID(uint(id))
	if err != nil || post.Status == model.PostStatusPending || post.Status == model.PostStatusLocked {
		c.HTML(http.StatusNotFound, "posts/404.html", common.BuildPageData(c, gin.H{
			"Title": "未找到或无法编辑",
		}))
		return
	}

	// 权限检查：仅作者和 moderator+ 可编辑
	var uid uint
	var role string
	if uidObj, exists := c.Get("uid"); exists {
		uid, _ = uidObj.(uint)
	}
	if roleObj, exists := c.Get("role"); exists {
		role, _ = roleObj.(string)
	}
	if post.UserID != uid && !model.HasMinRole(role, model.RoleModerator) {
		c.HTML(http.StatusNotFound, "posts/404.html", common.BuildPageData(c, gin.H{
			"Title": "未找到",
		}))
		return
	}

	c.HTML(http.StatusOK, "posts/new.html", common.BuildPageData(c, gin.H{
		"Title":    "编辑帖子",
		"Post":     post,
		"ExtraCSS": "/static/css/posts.css",
	}))
}

// Create API 发帖
func (ctrl *PostController) Create(c *gin.Context) {
	uidObj, _ := c.Get("uid")
	uid, ok := uidObj.(uint)
	if !ok {
		common.Error(c, http.StatusUnauthorized, "请先登录")
		return
	}

	var req model.PostCreateRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		common.Error(c, http.StatusBadRequest, "标题和正文不能为空")
		return
	}

	post, err := ctrl.postService.Create(uid, req.Title, req.Body)
	if err != nil {
		common.Error(c, http.StatusInternalServerError, "发帖失败")
		return
	}

	common.OkWithMessage(c, post, "发布成功")
}

// Update API 编辑帖子
func (ctrl *PostController) Update(c *gin.Context) {
	uidObj, _ := c.Get("uid")
	uid, ok := uidObj.(uint)
	if !ok {
		common.Error(c, http.StatusUnauthorized, "请先登录")
		return
	}

	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
	if err != nil {
		common.Error(c, http.StatusBadRequest, "无效的帖子 ID")
		return
	}

	var req model.PostUpdateRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		common.Error(c, http.StatusBadRequest, "标题和正文不能为空")
		return
	}

	// 权限检查：取帖子归属
	post, err := ctrl.postService.GetByID(uint(id))
	if err != nil {
		common.Error(c, http.StatusNotFound, "帖子不存在")
		return
	}
	roleObj, _ := c.Get("role")
	role, _ := roleObj.(string)
	if post.UserID != uid && !model.HasMinRole(role, model.RoleModerator) {
		common.Error(c, http.StatusForbidden, "无权编辑此帖子")
		return
	}

	if err := ctrl.postService.Update(uint(id), req.Title, req.Body); err != nil {
		if errors.Is(err, common.ErrPostCannotEdit) {
			common.Error(c, http.StatusBadRequest, err.Error())
		} else {
			common.Error(c, http.StatusInternalServerError, "编辑失败")
		}
		return
	}

	common.OkMessage(c, "编辑成功")
}

// Delete API 删除帖子
func (ctrl *PostController) Delete(c *gin.Context) {
	uidObj, _ := c.Get("uid")
	uid, ok := uidObj.(uint)
	if !ok {
		common.Error(c, http.StatusUnauthorized, "请先登录")
		return
	}

	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
	if err != nil {
		common.Error(c, http.StatusBadRequest, "无效的帖子 ID")
		return
	}

	post, err := ctrl.postService.GetByID(uint(id))
	if err != nil {
		common.Error(c, http.StatusNotFound, "帖子不存在")
		return
	}

	roleObj, _ := c.Get("role")
	role, _ := roleObj.(string)
	if post.UserID != uid && !model.HasMinRole(role, model.RoleModerator) {
		common.Error(c, http.StatusForbidden, "无权删除此帖子")
		return
	}

	if err := ctrl.postService.Delete(uint(id)); err != nil {
		common.Error(c, http.StatusInternalServerError, "删除失败")
		return
	}

	common.OkMessage(c, "删除成功")
}

// Submit API 提交审核
func (ctrl *PostController) Submit(c *gin.Context) {
	uidObj, _ := c.Get("uid")
	uid, ok := uidObj.(uint)
	if !ok {
		common.Error(c, http.StatusUnauthorized, "请先登录")
		return
	}

	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
	if err != nil {
		common.Error(c, http.StatusBadRequest, "无效的帖子 ID")
		return
	}

	// 权限检查：仅帖子作者可提交审核
	post, err := ctrl.postService.GetByID(uint(id))
	if err != nil {
		common.Error(c, http.StatusNotFound, "帖子不存在")
		return
	}
	if post.UserID != uid {
		common.Error(c, http.StatusForbidden, "无权操作此帖子")
		return
	}

	if err := ctrl.postService.SubmitForAudit(uint(id)); err != nil {
		if errors.Is(err, common.ErrPostCannotSubmit) || errors.Is(err, common.ErrPostNotFound) {
			common.Error(c, http.StatusBadRequest, err.Error())
		} else {
			common.Error(c, http.StatusInternalServerError, "提交审核失败")
		}
		return
	}

	common.OkMessage(c, "已提交审核")
}

// ListAPI 帖子列表 JSON API
func (ctrl *PostController) ListAPI(c *gin.Context) {
	keyword := c.Query("keyword")
	page, _ := strconv.Atoi(c.DefaultQuery("page", "1"))
	pageSize, _ := strconv.Atoi(c.DefaultQuery("page_size", "20"))

	posts, total, err := ctrl.postService.List(keyword, page, pageSize)
	if err != nil {
		common.Error(c, http.StatusInternalServerError, "获取帖子列表失败")
		return
	}

	if posts == nil {
		posts = []model.Post{}
	}

	p := common.Pagination{Page: page, PageSize: pageSize}
	p.DefaultPagination()

	common.Ok(c, model.PostListResult{
		Items:      posts,
		Total:      total,
		Page:       p.Page,
		TotalPages: p.TotalPages(total),
	})
}

// ShowAPI 帖子详情 JSON API
func (ctrl *PostController) ShowAPI(c *gin.Context) {
	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
	if err != nil {
		common.Error(c, http.StatusBadRequest, "无效的帖子 ID")
		return
	}

	post, err := ctrl.postService.GetByID(uint(id))
	if err != nil {
		common.Error(c, http.StatusNotFound, "帖子不存在")
		return
	}

	// 权限控制：非 approved 帖子仅作者和 moderator+ 可见
	if post.Status != model.PostStatusApproved {
		var uid uint
		var role string
		if uidObj, exists := c.Get("uid"); exists {
			uid, _ = uidObj.(uint)
		}
		if roleObj, exists := c.Get("role"); exists {
			role, _ = roleObj.(string)
		}
		isAuthor := uid == post.UserID
		isModerator := model.HasMinRole(role, model.RoleModerator)
		if !isAuthor && !isModerator {
			common.Error(c, http.StatusNotFound, "帖子不存在")
			return
		}
	}

	// 处理 shortcode：[zone:type:params] → HTML 占位符
	if ctrl.shortcodeSvc != nil {
		result := ctrl.shortcodeSvc.Process(post.Body)
		post.Body = result.ProcessedBody
	}

	common.Ok(c, post)
}

// allowedImageExt 允许的图片扩展名
var allowedImageExt = map[string]bool{
	".jpg": true, ".jpeg": true, ".png": true, ".gif": true, ".webp": true,
}

// UploadImage 上传帖子图片（需登录，multipart/form-data）
func (ctrl *PostController) UploadImage(c *gin.Context) {
	uidObj, _ := c.Get("uid")
	uid, ok := uidObj.(uint)
	if !ok {
		common.Error(c, http.StatusUnauthorized, "请先登录")
		return
	}

	file, header, err := c.Request.FormFile("file")
	if err != nil {
		common.Error(c, http.StatusBadRequest, "请选择文件")
		return
	}
	defer file.Close()

	// 检查扩展名
	ext := strings.ToLower(filepath.Ext(header.Filename))
	if !allowedImageExt[ext] {
		common.Error(c, http.StatusBadRequest, "仅支持 jpg / jpeg / png / gif / webp 格式")
		return
	}

	// 限制 5MB
	maxSize := int64(5 << 20)
	if header.Size > maxSize {
		common.Error(c, http.StatusBadRequest, "图片大小不能超过 5MB")
		return
	}

	// 存储路径
	storageDir := "storage/uploads/posts"
	if err := os.MkdirAll(storageDir, 0755); err != nil {
		common.Error(c, http.StatusInternalServerError, "存储初始化失败")
		return
	}

	// 唯一文件名：uid_timestamp.ext
	ts := time.Now().UnixMilli()
	filename := fmt.Sprintf("%d_%d%s", uid, ts, ext)
	savePath := filepath.Join(storageDir, filename)

	if err := saveUploadedFile(file, savePath); err != nil {
		common.Error(c, http.StatusInternalServerError, "保存图片失败")
		return
	}

	url := "/uploads/posts/" + filename
	common.VditorUploadOk(c, map[string]string{header.Filename: url})
}

// saveUploadedFile 将 multipart.File 写入目标路径
func saveUploadedFile(file multipart.File, dst string) error {
	out, err := os.Create(dst)
	if err != nil {
		return err
	}
	defer out.Close()

	// 限制读取 5MB 防止内存放大
	buf := make([]byte, 32*1024)
	for {
		n, err := file.Read(buf)
		if n > 0 {
			if _, writeErr := out.Write(buf[:n]); writeErr != nil {
				return writeErr
			}
		}
		if err != nil {
			break
		}
	}
	return nil
}