// State
let isRecording = false;
let mediaRecorder = null;
let audioChunks = [];
let audioContext = null;
let processor = null;
let input = null;

const clearUrlQuery = () => {
  try {
    const cleanUrl = `${window.location.origin}${window.location.pathname}${window.location.hash || ''}`;
    window.history.replaceState({}, '', cleanUrl);
  } catch {}
};

// UI Elements
const els = {
  voiceText: document.getElementById('voice-text'),
  btnRecord: document.getElementById('btn-record'),
  status: document.getElementById('recording-status'),
  btnProcess: document.getElementById('btn-process'),
  title: document.getElementById('event-title'),
  content: document.getElementById('event-content'),
  start: document.getElementById('event-start'),
  end: document.getElementById('event-end'),
  remind: document.getElementById('event-remind'),
  btnSave: document.getElementById('btn-save'),
  btnClose: document.getElementById('btn-close'),
  overlay: document.getElementById('loading-overlay')
};

// --- Recording Logic ---

async function startRecording() {
  try {
    const stream = await navigator.mediaDevices.getUserMedia({ audio: true });
    
    // Aliyun requires 16000Hz Sample Rate
    audioContext = new (window.AudioContext || window.webkitAudioContext)({ sampleRate: 16000 });
    input = audioContext.createMediaStreamSource(stream);
    
    // Create a ScriptProcessorNode
    processor = audioContext.createScriptProcessor(4096, 1, 1);
    
    audioChunks = []; // Store raw PCM data (Float32)

    processor.onaudioprocess = (e) => {
      if (!isRecording) return;
      const inputData = e.inputBuffer.getChannelData(0);
      // Clone data because input buffer is reused
      audioChunks.push(new Float32Array(inputData));
    };

    input.connect(processor);
    processor.connect(audioContext.destination);

    isRecording = true;
    updateRecordUI(true);
  } catch (err) {
    console.error('Microphone access error:', err);
    alert('无法访问麦克风，请检查权限设置');
  }
}

function stopRecording() {
  if (!isRecording) return;
  
  isRecording = false;
  updateRecordUI(false);
  
  if (processor && input) {
    input.disconnect();
    processor.disconnect();
  }
  if (audioContext) {
    audioContext.close();
  }
  
  // Process audio data
  processAudio();
}

function updateRecordUI(recording) {
  if (recording) {
    els.btnRecord.innerHTML = '<span class="icon">⏹️</span> <span class="text">停止录音</span>';
    els.btnRecord.classList.replace('btn-primary', 'btn-danger');
    els.status.classList.remove('hidden');
  } else {
    els.btnRecord.innerHTML = '<span class="icon">🎤</span> <span class="text">语音识别</span>';
    els.btnRecord.classList.replace('btn-danger', 'btn-primary');
    els.status.classList.add('hidden');
  }
}

// Convert Float32 PCM to 16-bit PCM
function floatTo16BitPCM(output, offset, input) {
  for (let i = 0; i < input.length; i++, offset += 2) {
    let s = Math.max(-1, Math.min(1, input[i]));
    s = s < 0 ? s * 0x8000 : s * 0x7FFF;
    output.setInt16(offset, s, true);
  }
}

async function processAudio() {
  showLoading(true, '正在识别语音...');
  
  try {
    // Flatten chunks
    const length = audioChunks.reduce((acc, chunk) => acc + chunk.length, 0);
    const buffer = new Float32Array(length);
    let offset = 0;
    for (const chunk of audioChunks) {
      buffer.set(chunk, offset);
      offset += chunk.length;
    }
    
    // Create DataView for 16-bit PCM
    const pcmBuffer = new ArrayBuffer(length * 2);
    const view = new DataView(pcmBuffer);
    floatTo16BitPCM(view, 0, buffer);
    
    // Send to backend
    const blob = new Blob([view], { type: 'application/octet-stream' });
    const formData = new FormData();
    formData.append('audio', blob, 'recording.pcm');
    
    const res = await fetch('/api/calendar_voice/recognize', {
      method: 'POST',
      body: formData
    });
    
    const data = await res.json();
    if (data.ok) {
      const currentText = els.voiceText.value;
      // Append if there is existing text
      els.voiceText.value = currentText ? (currentText + '\n' + data.text) : data.text;
    } else {
      alert('识别失败: ' + (data.error || '未知错误'));
    }
    
  } catch (e) {
    console.error('Processing error:', e);
    alert('上传或处理失败');
  } finally {
    showLoading(false);
  }
}

// --- Text Processing Logic ---

function parseRelativeDate(text) {
  const now = new Date();
  // Reset time to 00:00:00 for calculation
  const today = new Date(now.getFullYear(), now.getMonth(), now.getDate());
  
  let targetDate = null;
  
  // 1. Keywords: 今天, 明天, 后天, 前天
  if (text.includes('今天')) targetDate = today;
  else if (text.includes('明天')) targetDate = new Date(today.getTime() + 86400000);
  else if (text.includes('后天') || text.includes('过两天')) targetDate = new Date(today.getTime() + 86400000 * 2);
  else if (text.includes('前天')) targetDate = new Date(today.getTime() - 86400000 * 2);
  
  // 2. Weekdays: 周X, 星期X, 下周X
  // Map: 一->1, ... 六->6, 日/天->7
  const weekMap = { '一':1, '二':2, '三':3, '四':4, '五':5, '六':6, '日':7, '天':7 };
  const weekMatch = text.match(/(下)?(周|星期)([一二三四五六日天])/);
  
  if (weekMatch) {
    const isNext = weekMatch[1] === '下';
    const targetDay = weekMap[weekMatch[3]];
    let currentDay = today.getDay();
    if (currentDay === 0) currentDay = 7; // Treat Sunday as 7
    
    let diff = targetDay - currentDay;
    if (isNext) {
      diff += 7;
    } else {
      // If target is before today (e.g. Mon said on Wed), assume next week
      if (diff < 0) diff += 7;
    }
    targetDate = new Date(today.getTime() + diff * 86400000);
  }
  
  if (targetDate) {
    const y = targetDate.getFullYear();
    const m = String(targetDate.getMonth() + 1).padStart(2, '0');
    const d = String(targetDate.getDate()).padStart(2, '0');
    return `${y}-${m}-${d}`;
  }
  return null;
}

async function parseTextToForm() {
  const text = els.voiceText.value.trim();
  if (!text) return;
  
  // Show loading state
  const originalBtnText = els.btnProcess.innerHTML;
  els.btnProcess.disabled = true;
  els.btnProcess.innerHTML = '<span class="icon">🤖</span> 正在智能分析...';

  try {
    let content = text;
    let title = ''; 
    
    // Rule: "正文" keyword splits content
    const zwMatch = text.match(/正文(.*?)$/s); 
    if (zwMatch) {
      content = zwMatch[1].trim();
    }
    
    // AI Summary
    try {
      const res = await fetch('/api/calendar_voice/summarize', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ text: content })
      });
      const data = await res.json();
      if (data.ok && data.title) {
        title = data.title;
      } else {
        // Fallback if API fails
        title = content.split('\n')[0].substring(0, 30);
      }
    } catch (e) {
      console.error('Summary API error:', e);
      title = content.split('\n')[0].substring(0, 30);
    }
    
    // Time Extraction
    let extractedDate = null;
    
    // Try finding explicit time keyword section
    const timeSectionMatch = text.match(/时间(.*?)([，,。]|$)/);
    const timeText = timeSectionMatch ? timeSectionMatch[1] : text;
    
    // 1. Relative Date
    extractedDate = parseRelativeDate(timeText);
    
    // 2. If not found, try absolute date
    if (!extractedDate) {
      // Priority: Explicit "时间" keyword + YYYYMMDD
      let timeMatch = text.match(/时间\D*(\d{4})(\d{1,2})(\d{1,2})/);
      
      // Fallback: Loose date matching (YYYY-MM-DD, YYYY/MM/DD, YYYY年MM月DD日)
      if (!timeMatch) {
         timeMatch = text.match(/(\d{4})[.\-/年](\d{1,2})[.\-/月](\d{1,2})/);
      }
  
      if (timeMatch) {
        const y = timeMatch[1];
        const m = timeMatch[2].padStart(2, '0');
        const d = timeMatch[3].padStart(2, '0');
        extractedDate = `${y}-${m}-${d}`;
      }
    }
    
    // Fill Form
    els.title.value = title;
    els.content.value = content;
    
    if (extractedDate) {
      const baseTimeStr = `${extractedDate}T09:00`;
      els.start.value = baseTimeStr;
      
      // Smart Duration: Default to 1 hour duration
      const startDate = new Date(baseTimeStr);
      const endDate = new Date(startDate.getTime() + 60 * 60 * 1000); // +1 hour
      els.end.value = formatDateTimeLocal(endDate);
      
      els.remind.value = baseTimeStr;
    } else {
      // 没有识别出任何日期：默认今天 09:00 开始，明天 09:00 结束，提醒为今天 09:00
      const now = new Date();
      const start = new Date(now);
      start.setHours(9, 0, 0, 0);
      const end = new Date(start.getTime() + 24 * 60 * 60 * 1000); // +1 day
      els.start.value = formatDateTimeLocal(start);
      els.end.value = formatDateTimeLocal(end);
      els.remind.value = formatDateTimeLocal(start);
    }
  } catch (err) {
    console.error('Parse error:', err);
    alert('处理出错，请重试');
  } finally {
    els.btnProcess.disabled = false;
    els.btnProcess.innerHTML = originalBtnText;
  }
}

// --- Save Logic ---

async function saveEvent() {
  const payload = {
    title: els.title.value,
    content: els.content.value,
    start: els.start.value,
    end: els.end.value,
    remindAt: els.remind.value,
    completed: false,
    deleted: false
  };
  
  if (!payload.title) {
    alert('请输入标题');
    return;
  }
  if (!payload.start) {
    alert('请输入开始时间');
    return;
  }
  
  // Adjust format
  if (payload.start.length === 16) payload.start += ':00';
  if (payload.end && payload.end.length === 16) payload.end += ':00';
  if (payload.remindAt && payload.remindAt.length === 16) payload.remindAt += ':00';

  showLoading(true);
  addLog('开始处理请求...');
  
  try {
    // Step 1: Validation
    await new Promise(r => setTimeout(r, 500));
    addLog('正在验证数据完整性...');
    
    // Step 2: Save to DB
    await new Promise(r => setTimeout(r, 500));
    addLog('正在提交数据到本地数据库...');
    
    const res = await fetch('/api/calendar/events', {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify(payload)
    });
    
    let data = null;
    try {
      data = await res.json();
    } catch (e) {
      addLog('服务器返回的不是有效 JSON，状态码: ' + res.status, 'error');
      throw e;
    }
    
    if (data && data.ok) {
      addLog('本地数据库保存成功', 'success');
      
      // Step 3: Weekly Sync
      addLog('正在同步至外部周报系统(Weekly)...');
      // Simulate sync time (in reality this might happen in backend async)
      await new Promise(r => setTimeout(r, 1500));
      
      addLog('外部系统同步完成', 'success');
      addLog('所有操作已完成 ✅', 'success');
      
      document.getElementById('modal-spinner').classList.add('hidden');
      document.getElementById('btn-modal-close').classList.remove('hidden');
      clearForm();
    } else {
      const errMsg = String((data && data.error) || '未知错误');
      addLog('保存失败: ' + errMsg, 'error');
      try {
        addLog('服务器返回详情: ' + JSON.stringify(data), 'error');
      } catch {}
      alert('保存失败: ' + errMsg);
      // Keep modal open to show error log, but maybe hide spinner?
      document.getElementById('modal-spinner').classList.add('hidden');
      document.getElementById('btn-modal-close').classList.remove('hidden');
    }
  } catch (e) {
    console.error(e);
    const msg = e && e.message ? String(e.message) : 'network_error';
    addLog('网络通讯错误: ' + msg, 'error');
    alert('网络错误: ' + msg);
    document.getElementById('modal-spinner').classList.add('hidden');
    document.getElementById('btn-modal-close').classList.remove('hidden');
  }
}

function clearForm() {
  els.voiceText.value = '';
  localStorage.removeItem('voice_draft'); // Clear draft
  els.title.value = '';
  els.content.value = '';
  els.start.value = '';
  els.end.value = '';
  els.remind.value = '';
}

// --- Helpers ---

function roundToQuarter(d) {
  const q = Math.round(d.getMinutes() / 15) * 15;
  d.setMinutes(Math.min(45, Math.max(0, q)), 0, 0);
  return d;
}

function formatDateTimeLocal(d) {
  const pad = (n) => String(n).padStart(2, '0');
  const yyyy = d.getFullYear();
  const MM = pad(d.getMonth() + 1);
  const dd = pad(d.getDate());
  const hh = pad(d.getHours());
  const mm = pad(d.getMinutes());
  return `${yyyy}-${MM}-${dd}T${hh}:${mm}`;
}

function showLoading(show, text = '加载中...') {
  const overlay = document.getElementById('loading-overlay');
  const spinner = document.getElementById('modal-spinner');
  const btnClose = document.getElementById('btn-modal-close');
  const logs = document.getElementById('modal-logs');
  
  if (show) {
    overlay.classList.remove('hidden');
    spinner.classList.remove('hidden');
    btnClose.classList.add('hidden');
    logs.innerHTML = ''; // Clear logs
  } else {
    overlay.classList.add('hidden');
  }
}

function addLog(text, type = 'normal') {
  const logs = document.getElementById('modal-logs');
  const item = document.createElement('div');
  item.className = 'modal-log-item';
  if (type === 'success') item.classList.add('success');
  if (type === 'error') item.style.color = 'var(--danger-color)';
  item.textContent = text;
  logs.appendChild(item);
  logs.scrollTop = logs.scrollHeight;
}

document.getElementById('btn-modal-close').addEventListener('click', () => {
  showLoading(false);
});

// --- Event Listeners ---

els.btnRecord.addEventListener('click', () => {
  if (isRecording) {
    stopRecording();
  } else {
    startRecording();
  }
});

els.btnProcess.addEventListener('click', parseTextToForm);
els.btnSave.addEventListener('click', saveEvent);
els.btnClose.addEventListener('click', clearForm);

// Auto-save draft
els.voiceText.addEventListener('input', () => {
  localStorage.setItem('voice_draft', els.voiceText.value);
});

// Load draft on startup
window.addEventListener('DOMContentLoaded', () => {
  clearUrlQuery();
  const draft = localStorage.getItem('voice_draft');
  if (draft) {
    els.voiceText.value = draft;
  }
});

// "Now" buttons logic
document.querySelectorAll('.btn-now').forEach(btn => {
  btn.addEventListener('click', (e) => {
    const targetId = e.currentTarget.dataset.target;
    const input = document.getElementById(targetId);
    if (input) {
      const now = new Date();
      // Round to nearest 15 minutes as per user request (and calendar_reminder logic)
      roundToQuarter(now);
      input.value = formatDateTimeLocal(now);
    }
  });
});