// DOM Elements
const apiKeyInput = document.getElementById('apiKey');
const scriptUrlInput = document.getElementById('scriptUrl');
const modelInput = document.getElementById('modelInput');
const saveConfigBtn = document.getElementById('saveConfig');
const customInput = document.getElementById('customInput');
const sendCustomBtn = document.getElementById('sendCustom');
const statusBadge = document.getElementById('statusBadge');
const resultsArea = document.getElementById('results');

// Preset Management Elements
const newPresetName = document.getElementById('newPresetName');
const newPresetFields = document.getElementById('newPresetFields');
const addPresetBtn = document.getElementById('addPreset');
const presetList = document.getElementById('presetList');
const presetButtonsContainer = document.getElementById('presetButtons');

// Collapsible logic
const toggleConfig = document.getElementById('toggleConfig');
const configContent = document.getElementById('configContent');
const configChevron = document.getElementById('configChevron');

const DEFAULT_PRESETS = [
  { id: 'p1', name: '提取笔记本', fields: '品牌, CPU, 内存, 存储, 价格, URL' },
  { id: 'p2', name: '提取外设', fields: '品牌, 型号, 连接方式, 电池寿命, 价格, URL' }
];

toggleConfig.addEventListener('click', () => {
  const isHidden = configContent.classList.toggle('hidden');
  configChevron.classList.toggle('rotate-180', !isHidden);
});

// Load settings and presets on startup
chrome.storage.local.get(['geminiApiKey', 'googleScriptUrl', 'geminiModel', 'userPresets'], (data) => {
  if (data.geminiApiKey) {
    apiKeyInput.value = data.geminiApiKey;
    configContent.classList.add('hidden');
    configChevron.classList.remove('rotate-180');
  } else {
    configContent.classList.remove('hidden');
    configChevron.classList.add('rotate-180');
  }
  if (data.googleScriptUrl) scriptUrlInput.value = data.googleScriptUrl;
  if (data.geminiModel) modelInput.value = data.geminiModel;

  const presets = data.userPresets || DEFAULT_PRESETS;
  renderPresets(presets);
});

// Save settings (including presets is handled separately via add/delete)
saveConfigBtn.addEventListener('click', () => {
  const apiKey = apiKeyInput.value.trim();
  const scriptUrl = scriptUrlInput.value.trim();
  const model = modelInput.value.trim();
  chrome.storage.local.set({ 
    geminiApiKey: apiKey, 
    googleScriptUrl: scriptUrl,
    geminiModel: model
  }, () => {
    updateStatus('已保存', 'bg-green-500 text-white');
    setTimeout(() => updateStatus('待机', 'bg-gray-200 text-gray-600'), 2000);
  });
});

// Preset Management Logic
addPresetBtn.addEventListener('click', async () => {
  const name = newPresetName.value.trim();
  const fields = newPresetFields.value.trim();
  if (!name || !fields) return alert('请输入名称和字段');

  const { userPresets = DEFAULT_PRESETS } = await chrome.storage.local.get('userPresets');
  const newPreset = { id: Date.now().toString(), name, fields };
  const updatedPresets = [...userPresets, newPreset];

  await chrome.storage.local.set({ userPresets: updatedPresets });
  newPresetName.value = '';
  newPresetFields.value = '';
  renderPresets(updatedPresets);
});

async function deletePreset(id) {
  const { userPresets = DEFAULT_PRESETS } = await chrome.storage.local.get('userPresets');
  const updatedPresets = userPresets.filter(p => p.id !== id);
  await chrome.storage.local.set({ userPresets: updatedPresets });
  renderPresets(updatedPresets);
}

function renderPresets(presets) {
  // Clear containers
  presetList.innerHTML = '';
  presetButtonsContainer.innerHTML = '';

  presets.forEach(preset => {
    // 1. Render in Settings List
    const item = document.createElement('div');
    item.className = 'flex items-center justify-between bg-gray-50 p-2 rounded border border-gray-200 text-xs';
    item.innerHTML = `
      <div class="flex-1 overflow-hidden mr-2">
        <div class="font-bold truncate">${preset.name}</div>
        <div class="text-gray-500 truncate">${preset.fields}</div>
      </div>
      <button class="text-red-500 hover:text-red-700 font-bold p-1" data-id="${preset.id}">✕</button>
    `;
    item.querySelector('button').onclick = () => deletePreset(preset.id);
    presetList.appendChild(item);

    // 2. Render as Action Button
    const btn = document.createElement('button');
    btn.className = 'flex flex-col items-center justify-center p-4 bg-white border border-gray-200 rounded-lg hover:border-indigo-400 hover:bg-indigo-50 group transition-all';
    btn.innerHTML = `
      <span class="text-2xl mb-1 group-hover:scale-110 transition-transform">⚙️</span>
      <span class="text-xs font-semibold">${preset.name}</span>
    `;
    btn.onclick = () => handleExtraction('preset', preset);
    presetButtonsContainer.appendChild(btn);
  });
}

// Action Handlers
sendCustomBtn.addEventListener('click', () => handleExtraction('custom', { fields: customInput.value }));

async function handleExtraction(type, presetObj) {
  const { geminiApiKey, googleScriptUrl, geminiModel } = await chrome.storage.local.get(['geminiApiKey', 'googleScriptUrl', 'geminiModel']);
  
  if (!geminiApiKey) {
    alert('请先输入 Gemini API 密钥。');
    return;
  }

  const selectedModel = geminiModel || 'gemini-1.5-flash';
  updateStatus('提取中...', 'bg-blue-500 text-white');
  resultsArea.textContent = `正在使用 ${selectedModel} 提取 ${presetObj.name || '自定义项'}...`;

  try {
    const [tab] = await chrome.tabs.query({ active: true, currentWindow: true });
    const [{ result: pageData }] = await chrome.scripting.executeScript({
      target: { tabId: tab.id },
      files: ['content.js']
    });

    resultsArea.textContent = '正在发送至 Gemini...';
    
    const systemPrompt = `你是一个专业的采购助手。
请从以下文本中提取产品数据。
将技术术语翻译成中文。
仅返回有效的 JSON 格式。
如果可能，将本地货币转换为美元，或者保留原始符号。
URL: ${pageData.url}
Title: ${pageData.title}`;

    const userPrompt = `提取以下字段：${presetObj.fields}。仅返回 JSON 格式。`;

    const geminiResult = await callGemini(geminiApiKey, selectedModel, systemPrompt, pageData.text, userPrompt);
    const cleanedJson = parseGeminiJson(geminiResult);
    
    resultsArea.textContent = JSON.stringify(cleanedJson, null, 2);

    if (googleScriptUrl) {
      updateStatus('保存至表格...', 'bg-purple-500 text-white');
      await sendToGoogleScript(googleScriptUrl, { ...cleanedJson, preset_type: presetObj.name || 'custom', source_url: pageData.url, timestamp: new Date().toISOString() });
      updateStatus('成功', 'bg-green-500 text-white');
    } else {
      updateStatus('完成 (未配置脚本链接)', 'bg-yellow-500 text-white');
    }

  } catch (error) {
    console.error(error);
    updateStatus('错误', 'bg-red-500 text-white');
    resultsArea.textContent = `错误: ${error.message}`;
  }
}

async function callGemini(apiKey, model, systemPrompt, contextText, userPrompt) {
  const url = `https://generativelanguage.googleapis.com/v1beta/models/${model}:generateContent?key=${apiKey}`;
  const response = await fetch(url, {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({
      contents: [{
        parts: [{
          text: `${systemPrompt}\n\n上下文:\n${contextText}\n\n任务: ${userPrompt}`
        }]
      }]
    })
  });
  const data = await response.json();
  if (data.error) throw new Error(data.error.message);
  return data.candidates[0].content.parts[0].text;
}

function parseGeminiJson(text) {
  try {
    const jsonStr = text.replace(/```json/g, '').replace(/```/g, '').trim();
    return JSON.parse(jsonStr);
  } catch (e) {
    throw new Error('AI 返回了无效的 JSON: ' + text);
  }
}

async function sendToGoogleScript(url, payload) {
  return await fetch(url, {
    method: 'POST',
    mode: 'no-cors',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify(payload)
  });
}

function updateStatus(text, classes) {
  statusBadge.textContent = text;
  statusBadge.className = `status-badge ${classes}`;
}