(function() {
  const M = window.MusicRoom;
  
  document.addEventListener("DOMContentLoaded", () => {
    const addBtn = M.$("#btn-add");
    const addPanel = M.$("#add-panel");
    const addCloseBtn = M.$("#btn-add-close");
    const uploadFilesBtn = M.$("#btn-upload-files");
    const fileInput = M.$("#file-input");
    const dropzone = M.$("#upload-dropzone");
    const libraryPanel = M.$("#library-panel");
    const tasksList = M.$("#tasks-list");
    const tasksEmpty = M.$("#tasks-empty");
    
    if (!addBtn || !fileInput || !dropzone) return;
    
    function openPanel() {
      addPanel.classList.remove("hidden", "closing");
      addBtn.classList.add("hidden");
    }
    
    function closePanel() {
      addPanel.classList.add("closing");
      addBtn.classList.remove("hidden");
      addPanel.addEventListener("animationend", () => {
        if (addPanel.classList.contains("closing")) {
          addPanel.classList.add("hidden");
          addPanel.classList.remove("closing");
        }
      }, { once: true });
    }
    
    // Open add panel
    addBtn.onclick = () => {
      if (!M.currentUser) {
        M.showToast("Sign in to add tracks");
        return;
      }
      openPanel();
    };
    
    // Close add panel
    addCloseBtn.onclick = () => {
      closePanel();
    };
    
    // Upload files option
    uploadFilesBtn.onclick = () => {
      fileInput.click();
    };
    
    // File input change
    fileInput.onchange = () => {
      if (fileInput.files.length > 0) {
        closePanel();
        uploadFiles(fileInput.files);
        fileInput.value = "";
      }
    };
    
    // Drag and drop on library panel
    let dragCounter = 0;
    
    libraryPanel.ondragenter = (e) => {
      if (!M.currentUser) return;
      if (!e.dataTransfer.types.includes("Files")) return;
      e.preventDefault();
      dragCounter++;
      dropzone.classList.remove("hidden");
    };
    
    libraryPanel.ondragleave = (e) => {
      e.preventDefault();
      dragCounter--;
      if (dragCounter === 0) {
        dropzone.classList.add("hidden");
      }
    };
    
    libraryPanel.ondragover = (e) => {
      if (!M.currentUser) return;
      if (!e.dataTransfer.types.includes("Files")) return;
      e.preventDefault();
      e.dataTransfer.dropEffect = "copy";
    };
    
    libraryPanel.ondrop = (e) => {
      e.preventDefault();
      dragCounter = 0;
      dropzone.classList.add("hidden");
      
      if (!M.currentUser) {
        M.showToast("Sign in to upload");
        return;
      }
      
      const files = e.dataTransfer.files;
      if (files.length > 0) {
        uploadFiles(files);
      }
    };
    
    // Task management
    function updateTasksEmpty() {
      const hasTasks = tasksList.children.length > 0;
      tasksEmpty.classList.toggle("hidden", hasTasks);
    }
    
    function createTask(filename) {
      const task = document.createElement("div");
      task.className = "task-item";
      task.innerHTML = `
        <span class="task-spinner"></span>
        <span class="task-icon"></span>
        <span class="task-name">${filename}</span>
        <span class="task-progress">0%</span>
        <div class="task-bar" style="width: 0%"></div>
      `;
      tasksList.appendChild(task);
      updateTasksEmpty();
      
      // Switch to tasks tab
      const tasksTab = document.querySelector('.panel-tab[data-tab="tasks"]');
      if (tasksTab) tasksTab.click();
      
      return {
        setProgress(percent) {
          task.querySelector(".task-progress").textContent = `${Math.round(percent)}%`;
          task.querySelector(".task-bar").style.width = `${percent}%`;
        },
        setComplete() {
          task.classList.add("complete");
          task.querySelector(".task-progress").textContent = "Done";
          task.querySelector(".task-bar").style.width = "100%";
          // Remove after delay
          setTimeout(() => {
            task.remove();
            updateTasksEmpty();
          }, 3000);
        },
        setError(msg) {
          task.classList.add("error");
          task.querySelector(".task-progress").textContent = msg || "Failed";
          // Remove after delay
          setTimeout(() => {
            task.remove();
            updateTasksEmpty();
          }, 5000);
        }
      };
    }
    
    function uploadFile(file) {
      return new Promise((resolve) => {
        const task = createTask(file.name);
        const xhr = new XMLHttpRequest();
        const formData = new FormData();
        formData.append("file", file);
        
        xhr.upload.onprogress = (e) => {
          if (e.lengthComputable) {
            const percent = (e.loaded / e.total) * 100;
            task.setProgress(percent);
          }
        };
        
        xhr.onload = () => {
          if (xhr.status === 200) {
            task.setComplete();
            resolve({ success: true });
          } else if (xhr.status === 409) {
            task.setError("Duplicate");
            resolve({ success: false, duplicate: true });
          } else {
            task.setError("Failed");
            resolve({ success: false });
          }
        };
        
        xhr.onerror = () => {
          task.setError("Error");
          resolve({ success: false });
        };
        
        xhr.open("POST", "/api/upload");
        xhr.send(formData);
      });
    }
    
    async function uploadFiles(files) {
      const validExts = [".mp3", ".ogg", ".flac", ".wav", ".m4a", ".aac", ".opus", ".wma", ".mp4"];
      const audioFiles = [...files].filter(f => {
        const ext = f.name.toLowerCase().match(/\.[^.]+$/)?.[0];
        return ext && validExts.includes(ext);
      });
      
      if (audioFiles.length === 0) {
        M.showToast("No valid audio files");
        return;
      }
      
      let uploaded = 0;
      let failed = 0;
      
      // Upload files in parallel (max 3 concurrent)
      const concurrency = 3;
      const queue = [...audioFiles];
      const active = [];
      
      while (queue.length > 0 || active.length > 0) {
        while (active.length < concurrency && queue.length > 0) {
          const file = queue.shift();
          const promise = uploadFile(file).then(result => {
            if (result.success) uploaded++;
            else failed++;
            active.splice(active.indexOf(promise), 1);
          });
          active.push(promise);
        }
        if (active.length > 0) {
          await Promise.race(active);
        }
      }
      
      if (uploaded > 0) {
        M.showToast(`Uploaded ${uploaded} track${uploaded > 1 ? 's' : ''}${failed > 0 ? `, ${failed} failed` : ''}`);
      } else if (failed > 0) {
        M.showToast(`Upload failed`);
      }
    }
  });
})();