// 全域變數
let currentPage = 1;
let currentView = 'list';
let issues = [];
let projects = [];

// 頁面載入完成後初始化
document.addEventListener('DOMContentLoaded', function() {
    loadProjects();
    loadIssues();
    loadStats();
});

// 載入專案列表
async function loadProjects() {
    try {
        const response = await fetch('/api/projects');
        const result = await response.json();
        
        if (result.success) {
            projects = result.data;
            updateProjectSelects();
        } else {
            showAlert('載入專案失敗: ' + result.message, 'error');
        }
    } catch (error) {
        console.error('載入專案錯誤:', error);
        showAlert('載入專案時發生錯誤', 'error');
    }
}

// 更新專案選擇器
function updateProjectSelects() {
    const projectFilter = document.getElementById('projectFilter');
    const issueProject = document.getElementById('issueProject');
    
    // 清空現有選項
    projectFilter.innerHTML = '<option value="">全部專案</option>';
    issueProject.innerHTML = '<option value="">選擇專案</option>';
    
    // 添加專案選項
    projects.forEach(project => {
        const option1 = new Option(project.name, project.id);
        const option2 = new Option(project.name, project.id);
        projectFilter.appendChild(option1);
        issueProject.appendChild(option2);
    });
}

// 載入問題列表
async function loadIssues(page = 1) {
    currentPage = page;
    showLoading(true);
    
    try {
        const projectId = document.getElementById('projectFilter').value;
        const status = document.getElementById('statusFilter').value;
        const priority = document.getElementById('priorityFilter').value;
        
        let url = `/api/issues?page=${page}&limit=10`;
        if (projectId) url += `&project_id=${projectId}`;
        if (status) url += `&status=${status}`;
        if (priority) url += `&priority=${priority}`;
        
        const response = await fetch(url);
        const result = await response.json();
        
        if (result.success) {
            issues = result.data;
            renderIssues();
            renderPagination(result.pagination);
            updateStats();
        } else {
            showAlert('載入問題失敗: ' + result.message, 'error');
        }
    } catch (error) {
        console.error('載入問題錯誤:', error);
        showAlert('載入問題時發生錯誤', 'error');
    } finally {
        showLoading(false);
    }
}

// 渲染問題列表
function renderIssues() {
    const issuesList = document.getElementById('issuesList');
    
    if (issues.length === 0) {
        issuesList.innerHTML = `
            <div class="empty-state">
                <i class="fas fa-inbox"></i>
                <h3>沒有找到問題</h3>
                <p>目前沒有符合篩選條件的問題</p>
            </div>
        `;
        return;
    }
    
    const issuesHtml = issues.map(issue => `
        <div class="issue-item" onclick="showIssueDetail(${issue.id})">
            <div class="issue-header">
                <div>
                    <div class="issue-title">${escapeHtml(issue.title)}</div>
                    <div class="issue-meta">
                        <span><i class="fas fa-tag"></i> #${issue.id}</span>
                        <span><i class="fas fa-folder"></i> ${issue.project_name || '未分類'}</span>
                        <span><i class="fas fa-user"></i> ${issue.assignee || '未指派'}</span>
                        <span><i class="fas fa-calendar"></i> ${formatDate(issue.created_at)}</span>
                    </div>
                </div>
                <div>
                    <span class="status-badge status-${issue.status}">${getStatusText(issue.status)}</span>
                    <span class="priority-badge priority-${issue.priority}">${getPriorityText(issue.priority)}</span>
                </div>
            </div>
            ${issue.description ? `<div class="issue-description">${escapeHtml(issue.description)}</div>` : ''}
        </div>
    `).join('');
    
    issuesList.innerHTML = issuesHtml;
}

// 渲染分頁
function renderPagination(pagination) {
    const paginationDiv = document.getElementById('pagination');
    
    if (pagination.pages <= 1) {
        paginationDiv.innerHTML = '';
        return;
    }
    
    let paginationHtml = '';
    
    // 上一頁按鈕
    paginationHtml += `
        <button ${pagination.page === 1 ? 'disabled' : ''} onclick="loadIssues(${pagination.page - 1})">
            <i class="fas fa-chevron-left"></i> 上一頁
        </button>
    `;
    
    // 頁碼按鈕
    const startPage = Math.max(1, pagination.page - 2);
    const endPage = Math.min(pagination.pages, pagination.page + 2);
    
    for (let i = startPage; i <= endPage; i++) {
        paginationHtml += `
            <button class="${i === pagination.page ? 'active' : ''}" onclick="loadIssues(${i})">
                ${i}
            </button>
        `;
    }
    
    // 下一頁按鈕
    paginationHtml += `
        <button ${pagination.page === pagination.pages ? 'disabled' : ''} onclick="loadIssues(${pagination.page + 1})">
            下一頁 <i class="fas fa-chevron-right"></i>
        </button>
    `;
    
    paginationDiv.innerHTML = paginationHtml;
}

// 載入統計資料
async function loadStats() {
    try {
        const response = await fetch('/api/issues');
        const result = await response.json();
        
        if (result.success) {
            const stats = {
                open: 0,
                in_progress: 0,
                closed: 0,
                total: result.data.length
            };
            
            result.data.forEach(issue => {
                if (issue.status === 'open') stats.open++;
                else if (issue.status === 'in_progress') stats.in_progress++;
                else if (issue.status === 'closed') stats.closed++;
            });
            
            updateStatsDisplay(stats);
        }
    } catch (error) {
        console.error('載入統計錯誤:', error);
    }
}

// 更新統計顯示
function updateStatsDisplay(stats) {
    document.getElementById('openCount').textContent = stats.open;
    document.getElementById('progressCount').textContent = stats.in_progress;
    document.getElementById('closedCount').textContent = stats.closed;
    document.getElementById('totalCount').textContent = stats.total;
}

// 更新統計（從當前問題列表）
function updateStats() {
    const stats = {
        open: 0,
        in_progress: 0,
        closed: 0,
        total: issues.length
    };
    
    issues.forEach(issue => {
        if (issue.status === 'open') stats.open++;
        else if (issue.status === 'in_progress') stats.in_progress++;
        else if (issue.status === 'closed') stats.closed++;
    });
    
    updateStatsDisplay(stats);
}

// 顯示問題詳情
async function showIssueDetail(issueId) {
    try {
        const response = await fetch(`/api/issues/${issueId}`);
        const result = await response.json();
        
        if (result.success) {
            const issue = result.data;
            const modal = document.getElementById('issueDetailModal');
            const title = document.getElementById('issueDetailTitle');
            const content = document.getElementById('issueDetailContent');
            
            title.textContent = `#${issue.id} ${issue.title}`;
            
            content.innerHTML = `
                <div class="issue-detail">
                    <div class="issue-detail-header">
                        <div class="issue-meta">
                            <span><i class="fas fa-folder"></i> ${issue.project_name || '未分類'}</span>
                            <span><i class="fas fa-user"></i> ${issue.assignee || '未指派'}</span>
                            <span><i class="fas fa-calendar"></i> ${formatDate(issue.created_at)}</span>
                        </div>
                        <div>
                            <span class="status-badge status-${issue.status}">${getStatusText(issue.status)}</span>
                            <span class="priority-badge priority-${issue.priority}">${getPriorityText(issue.priority)}</span>
                        </div>
                    </div>
                    
                    <div class="issue-description">
                        <h4>描述</h4>
                        <p>${issue.description || '無描述'}</p>
                    </div>
                    
                    ${issue.comments && issue.comments.length > 0 ? `
                        <div class="issue-comments">
                            <h4>評論 (${issue.comments.length})</h4>
                            ${issue.comments.map(comment => `
                                <div class="comment">
                                    <div class="comment-header">
                                        <strong>${escapeHtml(comment.author)}</strong>
                                        <span class="comment-date">${formatDate(comment.created_at)}</span>
                                    </div>
                                    <div class="comment-content">${escapeHtml(comment.content)}</div>
                                </div>
                            `).join('')}
                        </div>
                    ` : ''}
                </div>
            `;
            
            showModal('issueDetailModal');
        } else {
            showAlert('載入問題詳情失敗: ' + result.message, 'error');
        }
    } catch (error) {
        console.error('載入問題詳情錯誤:', error);
        showAlert('載入問題詳情時發生錯誤', 'error');
    }
}

// 顯示新增問題模態框
function showCreateIssueModal() {
    showModal('createIssueModal');
}

// 顯示新增專案模態框
function showCreateProjectModal() {
    showModal('createProjectModal');
}

// 建立問題
async function createIssue() {
    const form = document.getElementById('createIssueForm');
    const formData = new FormData(form);
    
    const issueData = {
        title: formData.get('title'),
        description: formData.get('description'),
        project_id: formData.get('project_id') || null,
        priority: formData.get('priority'),
        assignee: formData.get('assignee'),
        reporter: formData.get('reporter')
    };
    
    if (!issueData.title) {
        showAlert('請填寫問題標題', 'error');
        return;
    }
    
    try {
        const response = await fetch('/api/issues', {
            method: 'POST',
            headers: {
                'Content-Type': 'application/json'
            },
            body: JSON.stringify(issueData)
        });
        
        const result = await response.json();
        
        if (result.success) {
            showAlert('問題建立成功！', 'success');
            closeModal('createIssueModal');
            form.reset();
            loadIssues();
            loadStats();
        } else {
            showAlert('建立問題失敗: ' + result.message, 'error');
        }
    } catch (error) {
        console.error('建立問題錯誤:', error);
        showAlert('建立問題時發生錯誤', 'error');
    }
}

// 建立專案
async function createProject() {
    const form = document.getElementById('createProjectForm');
    const formData = new FormData(form);
    
    const projectData = {
        name: formData.get('name'),
        description: formData.get('description'),
        status: formData.get('status')
    };
    
    if (!projectData.name) {
        showAlert('請填寫專案名稱', 'error');
        return;
    }
    
    try {
        const response = await fetch('/api/projects', {
            method: 'POST',
            headers: {
                'Content-Type': 'application/json'
            },
            body: JSON.stringify(projectData)
        });
        
        const result = await response.json();
        
        if (result.success) {
            showAlert('專案建立成功！', 'success');
            closeModal('createProjectModal');
            form.reset();
            loadProjects();
        } else {
            showAlert('建立專案失敗: ' + result.message, 'error');
        }
    } catch (error) {
        console.error('建立專案錯誤:', error);
        showAlert('建立專案時發生錯誤', 'error');
    }
}

// 切換檢視模式
function toggleView(view, el) {
    currentView = view;

    // 更新按鈕 active 樣式
    const buttons = document.querySelectorAll('.view-toggle .btn');
    buttons.forEach(btn => btn.classList.remove('active'));
    el.classList.add('active');

    // 切換容器樣式
    const issuesList = document.getElementById('issuesList');
    if (view === 'grid') {
        issuesList.classList.remove('issues-list');
        issuesList.classList.add('issues-grid');
    } else {
        issuesList.classList.remove('issues-grid');
        issuesList.classList.add('issues-list');
    }

    renderIssues();
}



// 顯示模態框
function showModal(modalId) {
    const modal = document.getElementById(modalId);
    modal.classList.add('show');
    modal.style.display = 'flex';
}

// 關閉模態框
function closeModal(modalId) {
    const modal = document.getElementById(modalId);
    modal.classList.remove('show');
    modal.style.display = 'none';
}

// 顯示載入指示器
function showLoading(show) {
    const loading = document.getElementById('loadingIndicator');
    loading.style.display = show ? 'block' : 'none';
}

// 顯示警告訊息
function showAlert(message, type = 'info') {
    // 移除現有的警告
    const existingAlert = document.querySelector('.alert');
    if (existingAlert) {
        existingAlert.remove();
    }
    
    const alert = document.createElement('div');
    alert.className = `alert alert-${type}`;
    alert.textContent = message;
    
    document.querySelector('.container').insertBefore(alert, document.querySelector('.stats-grid'));
    
    // 3秒後自動移除
    setTimeout(() => {
        if (alert.parentNode) {
            alert.remove();
        }
    }, 3000);
}

// 工具函數
function escapeHtml(text) {
    const div = document.createElement('div');
    div.textContent = text;
    return div.innerHTML;
}

function formatDate(dateString) {
    const date = new Date(dateString);
    return date.toLocaleDateString('zh-TW', {
        year: 'numeric',
        month: '2-digit',
        day: '2-digit',
        hour: '2-digit',
        minute: '2-digit'
    });
}

function getStatusText(status) {
    const statusMap = {
        'open': '待處理',
        'in_progress': '處理中',
        'closed': '已完成'
    };
    return statusMap[status] || status;
}

function getPriorityText(priority) {
    const priorityMap = {
        'high': '高',
        'medium': '中',
        'low': '低'
    };
    return priorityMap[priority] || priority;
}

// 點擊模態框外部關閉
window.onclick = function(event) {
    const modals = document.querySelectorAll('.modal');
    modals.forEach(modal => {
        if (event.target === modal) {
            modal.classList.remove('show');
            modal.style.display = 'none';
        }
    });
}