/*
 * Project: Video Sharing Platform
 * Year: 2026
 * Developed by: Molla Samser (Founder of RSK World)
 * 
 * Video upload and processing system with progress tracking.
 */

package main

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

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

type UploadProgress struct {
	ID           string  `json:"id"`
	Filename     string  `json:"filename"`
	Progress     float64 `json:"progress"`
	Status       string  `json:"status"`
	ThumbnailURL string  `json:"thumbnail_url"`
	VideoURL     string  `json:"video_url"`
	Error        string  `json:"error,omitempty"`
}

type UploadRequest struct {
	Title       string   `json:"title"`
	Description string   `json:"description"`
	Tags        []string `json:"tags"`
	Category    string   `json:"category"`
	IsPrivate   bool     `json:"is_private"`
}

var uploadProgressMap = make(map[string]*UploadProgress)
var uploadIDCounter = 0

func UploadVideo(c *gin.Context) {
	// Get user from context (from auth middleware)
	userID := c.GetInt("user_id")
	if userID == 0 {
		c.JSON(http.StatusUnauthorized, gin.H{"error": "Authentication required"})
		return
	}

	// Parse multipart form
	err := c.Request.ParseMultipartForm(32 << 20) // 32MB max
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "Unable to parse form"})
		return
	}

	// Get file from form
	file, header, err := c.Request.FormFile("video")
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "No video file provided"})
		return
	}
	defer file.Close()

	// Get form data
	title := c.PostForm("title")
	description := c.PostForm("description")
	category := c.PostForm("category")
	tags := strings.Split(c.PostForm("tags"), ",")
	isPrivate := c.PostForm("is_private") == "true"

	// Generate unique upload ID
	uploadIDCounter++
	uploadID := fmt.Sprintf("upload_%d_%d", userID, uploadIDCounter)

	// Create upload progress tracker
	progress := &UploadProgress{
		ID:       uploadID,
		Filename: header.Filename,
		Progress: 0,
		Status:   "processing",
	}
	uploadProgressMap[uploadID] = progress

	// Start upload in background
	go processVideoUpload(file, header, title, description, tags, category, isPrivate, userID, uploadID)

	c.JSON(http.StatusAccepted, gin.H{
		"status":     "upload_started",
		"upload_id":  uploadID,
		"message":    "Video upload and processing started",
	})
}

func processVideoUpload(file io.Reader, header *multipart.FileHeader, title, description string, tags []string, category string, isPrivate bool, userID int, uploadID string) {
	progress := uploadProgressMap[uploadID]
	
	// Create uploads directory if it doesn't exist
	uploadDir := "uploads/videos"
	os.MkdirAll(uploadDir, 0755)
	
	// Save video file
	filename := fmt.Sprintf("%d_%s", userID, header.Filename)
	filePath := filepath.Join(uploadDir, filename)
	
	dst, err := os.Create(filePath)
	if err != nil {
		progress.Status = "error"
		progress.Error = "Failed to save file"
		return
	}
	defer dst.Close()

	// Copy file with progress tracking
	size := header.Size
	written, err := io.Copy(dst, file)
	if err != nil {
		progress.Status = "error"
		progress.Error = "Failed to save file"
		return
	}

	progress.Progress = 100
	progress.Status = "processing"

	// Process video (thumbnail, transcoding, etc.)
	go processVideoContent(filePath, uploadID, title, description, tags, category, isPrivate, userID)
}

func processVideoContent(filePath, uploadID, title, description string, tags []string, category string, isPrivate bool, userID int) {
	progress := uploadProgressMap[uploadID]
	
	progress.Status = "generating_thumbnail"
	time.Sleep(1 * time.Second) // Simulate processing
	
	progress.Status = "transcoding"
	time.Sleep(2 * time.Second) // Simulate processing
	
	progress.Status = "optimizing"
	time.Sleep(1 * time.Second) // Simulate processing

	// Generate URLs
	videoURL := fmt.Sprintf("/static/videos/%s", filepath.Base(filePath))
	thumbnailURL := fmt.Sprintf("/static/thumbnails/%s.jpg", filepath.Base(filePath))

	// Create video record
	newVideo := Video{
		ID:          len(videos) + 1,
		Title:       title,
		Description: description,
		Creator:     getUserByID(userID).Username,
		URL:         videoURL,
		Tags:        tags,
	}

	videos = append(videos, newVideo)

	// Update progress
	progress.VideoURL = videoURL
	progress.ThumbnailURL = thumbnailURL
	progress.Status = "completed"
	progress.Progress = 100
}

func GetUploadProgress(c *gin.Context) {
	uploadID := c.Param("upload_id")
	
	progress, exists := uploadProgressMap[uploadID]
	if !exists {
		c.JSON(http.StatusNotFound, gin.H{"error": "Upload not found"})
		return
	}

	c.JSON(http.StatusOK, gin.H{
		"upload_id": uploadID,
		"progress":  progress,
	})
}

func GetUploads(c *gin.Context) {
	userID := c.GetInt("user_id")
	if userID == 0 {
		c.JSON(http.StatusUnauthorized, gin.H{"error": "Authentication required"})
		return
	}

	// Filter videos by user
	userVideos := []Video{}
	for _, video := range videos {
		if video.Creator == getUserByID(userID).Username {
			userVideos = append(userVideos, video)
		}
	}

	c.JSON(http.StatusOK, gin.H{
		"videos": userVideos,
		"count":  len(userVideos),
	})
}

func getUserByID(userID int) User {
	for _, user := range users {
		if user.ID == userID {
			return user
		}
	}
	return User{}
}

// WebSocket endpoint for real-time progress updates
func UploadProgressWebSocket(c *gin.Context) {
	// This would implement WebSocket for real-time progress updates
	// For now, return a simple response
	c.JSON(http.StatusOK, gin.H{
		"message": "WebSocket endpoint for upload progress",
		"note":    "Implement WebSocket for real-time updates",
	})
}
