/**
 * PDF翻译助手前端脚本
 */

// 当前翻译ID
let currentTranslationId = null;
let currentTaskId = null;

// 上传表单处理
document.getElementById('uploadForm').addEventListener('submit', async function(e) {
    e.preventDefault();
    
    const fileInput = document.getElementById('pdfFile');
    const file = fileInput.files[0];
    
    if (!file) {
        alert('请选择PDF文件');
        return;
    }
    
    if (!file.name.toLowerCase().endsWith('.pdf')) {
        alert('只支持PDF文件');
        return;
    }
    
    // 显示进度区域
    document.getElementById('progressSection').style.display = 'block';
    document.getElementById('resultSection').style.display = 'none';
    document.getElementById('cacheNotice').style.display = 'none';
    
    // 显示加载状态
    const submitBtn = document.getElementById('submitBtn');
    const btnText = document.getElementById('btnText');
    const btnSpinner = document.getElementById('btnSpinner');
    
    submitBtn.disabled = true;
    btnText.textContent = '上传中...';
    btnSpinner.style.display = 'inline-block';
    
    // 构建表单数据
    const formData = new FormData();
    formData.append('file', file);
    
    const instruction = document.getElementById('instruction')?.value;
    if (instruction) {
        formData.append('instruction', instruction);
    }
    
    try {
        // 上传文件
        const response = await fetch('/api/upload', {
            method: 'POST',
            body: formData
        });
        
        const result = await response.json();
        
        if (!response.ok) {
            throw new Error(result.error || '上传失败');
        }
        
        currentTranslationId = result.translation_id;
        currentTaskId = result.task_id;
        
        // 如果使用缓存，直接显示结果
        if (result.from_cache) {
            document.getElementById('cacheNotice').style.display = 'block';
            showResult(currentTranslationId);
        } else {
            // 开始轮询进度
            pollProgress(currentTaskId, currentTranslationId);
        }
        
    } catch (error) {
        alert('上传失败: ' + error.message);
        resetUploadButton();
    }
});

// 轮询翻译进度
async function pollProgress(taskId, translationId) {
    const progressBar = document.getElementById('progressBar');
    const progressMessage = document.getElementById('progressMessage');
    
    const poll = async () => {
        try {
            // 同时检查任务状态和翻译状态
            const taskResponse = await fetch(`/api/task/${taskId}`);
            const taskResult = await taskResponse.json();
            
            const transResponse = await fetch(`/api/status/${translationId}`);
            const transResult = await transResponse.json();
            
            // 更新进度
            if (taskResult.progress) {
                progressBar.style.width = taskResult.progress + '%';
                progressBar.textContent = taskResult.progress + '%';
            }
            
            if (taskResult.message) {
                progressMessage.textContent = taskResult.message;
            }
            
            // 检查是否完成
            if (taskResult.status === 'completed' || transResult.status === 'completed') {
                progressBar.style.width = '100%';
                progressBar.textContent = '100%';
                progressMessage.textContent = '翻译完成！';
                
                // 显示结果
                setTimeout(() => showResult(translationId), 500);
                return;
            }
            
            if (taskResult.status === 'failed') {
                progressMessage.textContent = '翻译失败: ' + (taskResult.error || '未知错误');
                resetUploadButton();
                return;
            }
            
            // 继续轮询
            setTimeout(poll, 2000);
            
        } catch (error) {
            console.error('轮询失败:', error);
            setTimeout(poll, 3000);
        }
    };
    
    poll();
}

// 显示翻译结果
async function showResult(translationId) {
    const resultSection = document.getElementById('resultSection');
    const resultContent = document.getElementById('resultContent');
    
    try {
        const response = await fetch(`/api/result/${translationId}`);
        const result = await response.json();
        
        if (!response.ok) {
            throw new Error(result.error || '获取结果失败');
        }
        
        // 渲染Markdown内容
        resultContent.innerHTML = renderMarkdown(result.content);
        resultSection.style.display = 'block';
        
        resetUploadButton();
        
    } catch (error) {
        alert('获取结果失败: ' + error.message);
        resetUploadButton();
    }
}

// 重置上传按钮
function resetUploadButton() {
    const submitBtn = document.getElementById('submitBtn');
    const btnText = document.getElementById('btnText');
    const btnSpinner = document.getElementById('btnSpinner');
    
    submitBtn.disabled = false;
    btnText.textContent = '开始翻译';
    btnSpinner.style.display = 'none';
}

// 下载结果
document.getElementById('downloadBtn')?.addEventListener('click', function() {
    if (currentTranslationId) {
        window.location.href = `/api/download/${currentTranslationId}`;
    }
});

// 对比查看
document.getElementById('viewCompare')?.addEventListener('click', async function() {
    if (!currentTranslationId) return;
    
    try {
        const response = await fetch(`/api/compare/${currentTranslationId}`);
        const result = await response.json();
        
        // 显示对比视图
        showCompareView(result);
        
    } catch (error) {
        alert('获取对比失败: ' + error.message);
    }
});

// 显示对比视图
function showCompareView(data) {
    const resultContent = document.getElementById('resultContent');
    
    resultContent.innerHTML = `
        <div class="compare-container">
            <div class="compare-panel original">
                <h5>原文</h5>
                <div class="content">${escapeHtml(data.original)}</div>
            </div>
            <div class="compare-panel translated">
                <h5>译文</h5>
                <div class="content">${renderMarkdown(data.translated)}</div>
            </div>
        </div>
    `;
}

// 重新翻译
document.getElementById('retranslateBtn')?.addEventListener('click', async function() {
    if (!currentTranslationId) return;
    
    const instruction = document.getElementById('retranslateInstruction').value;
    if (!instruction.trim()) {
        alert('请输入翻译要求');
        return;
    }
    
    try {
        const response = await fetch(`/api/retranslate/${currentTranslationId}`, {
            method: 'POST',
            headers: {'Content-Type': 'application/json'},
            body: JSON.stringify({instruction: instruction})
        });
        
        const result = await response.json();
        
        if (!response.ok) {
            throw new Error(result.error || '重译请求失败');
        }
        
        // 开始新的翻译任务
        currentTranslationId = result.translation_id;
        document.getElementById('progressSection').style.display = 'block';
        document.getElementById('resultSection').style.display = 'none';
        pollProgress(null, currentTranslationId);
        
    } catch (error) {
        alert('重译失败: ' + error.message);
    }
});

// 简单Markdown渲染
function renderMarkdown(text) {
    // 标题
    text = text.replace(/^## (.*)$/gm, '<h2>$1</h2>');
    text = text.replace(/^# (.*)$/gm, '<h1>$1</h1>');
    
    // 分隔线
    text = text.replace(/^---$/gm, '<hr>');
    
    // 引用
    text = text.replace(/^> (.*)$/gm, '<blockquote>$1</blockquote>');
    
    // 段落
    text = text.replace(/\n\n/g, '</p><p>');
    text = '<p>' + text + '</p>';
    
    return text;
}

// HTML转义
function escapeHtml(text) {
    const div = document.createElement('div');
    div.textContent = text;
    return div.innerHTML;
}

// 检查用户登录状态
async function checkUserStatus() {
    try {
        const response = await fetch('/api/user/info');
        const result = await response.json();
        
        if (result.user) {
            console.log('用户已登录:', result.user.username);
        }
        
    } catch (error) {
        console.error('检查用户状态失败:', error);
    }
}

// 页面加载时检查状态
document.addEventListener('DOMContentLoaded', checkUserStatus);