package controller

import (
	"fmt"
	"io"
	"net/http"
	"os"
	"path/filepath"
	"strconv"
	"strings"

	"github.com/gin-gonic/gin"
	"gorm.io/gorm"

	"ezops/model"
)

// WorkspaceFilesHandler 工作区文件浏览器处理器
type WorkspaceFilesHandler struct {
	db *gorm.DB
}

func NewWorkspaceFilesHandler(db *gorm.DB) *WorkspaceFilesHandler {
	return &WorkspaceFilesHandler{db: db}
}

// FileInfo 文件信息
type FileInfo struct {
	Name    string `json:"name"`
	Path    string `json:"path"`
	IsDir   bool   `json:"is_dir"`
	Size    int64  `json:"size"`
	ModTime string `json:"mod_time"`
}

// resolveWorkspace 解析 run ID 获取 workspace 路径
func (h *WorkspaceFilesHandler) resolveWorkspace(c *gin.Context) (string, error) {
	runID, err := strconv.Atoi(c.Param("runId"))
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid run id"})
		return "", err
	}

	var run model.PipelineRun
	if err := h.db.First(&run, runID).Error; err != nil {
		c.JSON(http.StatusNotFound, gin.H{"error": "run not found"})
		return "", err
	}

	if run.WorkspacePath == "" {
		c.JSON(http.StatusNotFound, gin.H{"error": "workspace path not available, pipeline may still be running"})
		return "", fmt.Errorf("no workspace")
	}

	return run.WorkspacePath, nil
}

// safePath 安全拼接路径，防止目录穿越
func safePath(base, sub string) (string, error) {
	if sub == "" || sub == "." {
		sub = "/"
	}
	// 清理路径
	clean := filepath.Clean(sub)
	if filepath.IsAbs(clean) {
		// 去掉根前缀，转为相对路径
		clean = clean[1:]
	}
	fullPath := filepath.Join(base, clean)
	// 确保不逃逸出 base
	absBase, _ := filepath.Abs(base)
	absFull, err := filepath.Abs(fullPath)
	if err != nil {
		return "", fmt.Errorf("invalid path")
	}
	if !strings.HasPrefix(absFull, absBase) {
		return "", fmt.Errorf("path traversal detected")
	}
	return fullPath, nil
}

// ListFiles 列出目录内容
// GET /api/v1/pipelines/runs/:runId/files?path=subdir
func (h *WorkspaceFilesHandler) ListFiles(c *gin.Context) {
	workspace, err := h.resolveWorkspace(c)
	if err != nil {
		return
	}

	subPath := c.Query("path")
	targetPath, err := safePath(workspace, subPath)
	if err != nil {
		c.JSON(http.StatusForbidden, gin.H{"error": err.Error()})
		return
	}

	entries, err := os.ReadDir(targetPath)
	if err != nil {
		if os.IsNotExist(err) {
			c.JSON(http.StatusNotFound, gin.H{"error": "directory not found"})
		} else {
			c.JSON(http.StatusInternalServerError, gin.H{"error": "failed to read directory"})
		}
		return
	}

	files := make([]FileInfo, 0)
	dirs := make([]FileInfo, 0)

	for _, entry := range entries {
		info, err := entry.Info()
		if err != nil {
			continue
		}
		rel, _ := filepath.Rel(workspace, filepath.Join(targetPath, entry.Name()))
		fi := FileInfo{
			Name:    entry.Name(),
			Path:    rel,
			IsDir:   entry.IsDir(),
			Size:    info.Size(),
			ModTime: info.ModTime().Format("2006-01-02 15:04:05"),
		}
		if entry.IsDir() {
			dirs = append(dirs, fi)
		} else {
			files = append(files, fi)
		}
	}

	// 当前路径（相对于 workspace）
	currentRel, _ := filepath.Rel(workspace, targetPath)
	if currentRel == "." {
		currentRel = ""
	}

	c.JSON(http.StatusOK, gin.H{
		"current": currentRel,
		"dirs":    dirs,
		"files":   files,
	})
}

// DownloadFile 下载文件
// GET /api/v1/pipelines/runs/:runId/files/download?path=file
func (h *WorkspaceFilesHandler) DownloadFile(c *gin.Context) {
	workspace, err := h.resolveWorkspace(c)
	if err != nil {
		return
	}

	subPath := c.Query("path")
	if subPath == "" {
		c.JSON(http.StatusBadRequest, gin.H{"error": "path is required"})
		return
	}

	targetPath, err := safePath(workspace, subPath)
	if err != nil {
		c.JSON(http.StatusForbidden, gin.H{"error": err.Error()})
		return
	}

	info, err := os.Stat(targetPath)
	if err != nil {
		c.JSON(http.StatusNotFound, gin.H{"error": "file not found"})
		return
	}
	if info.IsDir() {
		c.JSON(http.StatusBadRequest, gin.H{"error": "cannot download a directory"})
		return
	}

	file, err := os.Open(targetPath)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "failed to open file"})
		return
	}
	defer file.Close()

	c.Header("Content-Disposition", fmt.Sprintf("attachment; filename=\"%s\"", filepath.Base(targetPath)))
	c.Header("Content-Type", "application/octet-stream")
	c.Header("Content-Length", fmt.Sprintf("%d", info.Size()))
	io.Copy(c.Writer, file)
}