{% extends "base.html" %}

{% block content %}
<div class="container-fluid py-4">
    <h2 class="mb-4">🎯 目标管理</h2>

    <!-- 目标列表 -->
    <div class="row">
        <div class="col-12">
            <div class="card">
                <div class="card-header d-flex justify-content-between align-items-center">
                    <h5 class="mb-0">目标库</h5>
                    <button class="btn btn-primary btn-sm" data-bs-toggle="modal" data-bs-target="#goalModal">
                        + 新建目标
                    </button>
                </div>
                <div class="card-body">
                    <div id="goals-grid" class="row g-3"></div>
                </div>
            </div>
        </div>
    </div>
</div>

<!-- 目标编辑 Modal -->
<div class="modal fade" id="goalModal" tabindex="-1">
    <div class="modal-dialog">
        <div class="modal-content">
            <div class="modal-header">
                <h5 class="modal-title" id="goalModalTitle">新建目标</h5>
                <button type="button" class="btn-close" data-bs-dismiss="modal"></button>
            </div>
            <div class="modal-body">
                <input type="hidden" id="goal-id">
                <div class="mb-3">
                    <label class="form-label">目标名称</label>
                    <input type="text" class="form-control" id="goal-name" required>
                </div>
                <div class="mb-3">
                    <label class="form-label">级别</label>
                    <select class="form-select" id="goal-level">
                        <option value="启蒙">启蒙</option>
                        <option value="入门" selected>入门</option>
                        <option value="进阶">进阶</option>
                        <option value="熟练">熟练</option>
                        <option value="精通">精通</option>
                    </select>
                </div>
                <div class="mb-3">
                    <label class="form-label">目标内容 (Markdown)</label>
                    <textarea class="form-control" id="goal-content" rows="8"></textarea>
                </div>
            </div>
            <div class="modal-footer">
                <button type="button" class="btn btn-secondary" data-bs-dismiss="modal">取消</button>
                <button type="button" class="btn btn-primary" id="save-goal">保存</button>
            </div>
        </div>
    </div>
</div>

<!-- 关系管理 Modal -->
<div class="modal fade" id="relationModal" tabindex="-1">
    <div class="modal-dialog modal-lg">
        <div class="modal-content">
            <div class="modal-header">
                <h5 class="modal-title" id="relationModalTitle">管理子目标</h5>
                <button type="button" class="btn-close" data-bs-dismiss="modal"></button>
            </div>
            <div class="modal-body">
                <input type="hidden" id="relation-goal-id">
                <p class="text-muted">为「<span id="current-goal-name" class="fw-bold"></span>」添加子目标</p>

                <!-- 添加子目标区域 -->
                <div class="mb-3">
                    <label class="form-label">添加子目标（可多选）</label>
                    <select class="form-select" id="available-goals-select" multiple size="5">
                    </select>
                    <div class="form-text">按住 Ctrl/Cmd 可多选</div>
                </div>
                <button class="btn btn-primary btn-sm mb-3" onclick="addSelectedChildren()">
                    <i class="bi bi-plus"></i> 添加选中目标
                </button>

                <!-- 已关联的子目标 -->
                <h6 class="mt-3">已关联的子目标</h6>
                <div id="child-goals-list" class="list-group"></div>
            </div>
        </div>
    </div>
</div>
{% endblock %}

{% block extra_js %}
{{ super() }}
<script>
const API_BASE = '/api/goals';

// 加载目标列表
async function loadGoals() {
    const res = await fetch(API_BASE);
    const goals = await res.json();
    const grid = document.getElementById('goals-grid');

    // 获取每个目标的子目标数量
    const goalsWithChildren = await Promise.all(goals.map(async g => {
        const childrenRes = await fetch(`${API_BASE}/${g.id}/children`);
        const children = await childrenRes.json();
        return {...g, childCount: children.length};
    }));

    grid.innerHTML = goalsWithChildren.map(g => `
        <div class="col-md-4 col-lg-3">
            <div class="card h-100">
                <div class="card-body">
                    <h6 class="card-title">${escapeHtml(g.name)}</h6>
                    <div class="mb-1">
                        <span class="badge bg-secondary">${g.level}</span>
                        ${g.childCount > 0 ? `<span class="badge bg-info">${g.childCount}个子目标</span>` : ''}
                    </div>
                    <p class="card-text small text-muted">${escapeHtml(g.content || '').substring(0, 80)}${g.content && g.content.length > 80 ? '...' : ''}</p>
                </div>
                <div class="card-footer bg-transparent">
                    <button class="btn btn-sm btn-outline-primary" onclick="editGoal(${g.id})">编辑</button>
                    <button class="btn btn-sm btn-outline-secondary" onclick="manageRelations(${g.id})">关联</button>
                    <button class="btn btn-sm btn-outline-danger" onclick="deleteGoal(${g.id})">删除</button>
                </div>
            </div>
        </div>
    `).join('');
}

// 保存目标
async function saveGoal() {
    const id = document.getElementById('goal-id').value;
    const name = document.getElementById('goal-name').value;
    const level = document.getElementById('goal-level').value;
    const content = document.getElementById('goal-content').value;

    if (!name) { alert('请输入目标名称'); return; }

    const method = id ? 'PUT' : 'POST';
    const url = id ? `${API_BASE}/${id}` : API_BASE;

    try {
        const res = await fetch(url, {
            method,
            headers: {'Content-Type': 'application/json'},
            body: JSON.stringify({name, level, content})
        });

        if (res.ok) {
            bootstrap.Modal.getInstance(document.getElementById('goalModal')).hide();
            loadGoals();
        } else {
            const err = await res.json();
            alert(err.error || '保存失败');
        }
    } catch (e) {
        alert('网络错误: ' + e.message);
    }
}

function editGoal(id) {
    fetch(`${API_BASE}/${id}`)
        .then(r => r.json())
        .then(g => {
            document.getElementById('goal-id').value = g.id;
            document.getElementById('goal-name').value = g.name;
            document.getElementById('goal-level').value = g.level || '入门';
            document.getElementById('goal-content').value = g.content || '';
            document.getElementById('goalModalTitle').textContent = '编辑目标';
            new bootstrap.Modal(document.getElementById('goalModal')).show();
        });
}

async function deleteGoal(id) {
    if (!confirm('确定删除此目标？')) return;
    await fetch(`${API_BASE}/${id}`, {method: 'DELETE'});
    loadGoals();
}

async function manageRelations(id) {
    document.getElementById('relation-goal-id').value = id;

    // 获取当前目标信息和所有目标
    const [currentGoal, allGoals, children] = await Promise.all([
        fetch(`${API_BASE}/${id}`).then(r => r.json()),
        fetch(API_BASE).then(r => r.json()),
        fetch(`${API_BASE}/${id}/children`).then(r => r.json())
    ]);

    // 显示当前目标名称
    document.getElementById('current-goal-name').textContent = currentGoal.name;

    // 已关联的子目标
    const childIds = children.map(c => c.id);
    renderChildrenList(children, id);

    // 可选的子目标（下拉列表中排除自己 和 已关联的）
    const availableSelect = document.getElementById('available-goals-select');
    availableSelect.innerHTML = allGoals
        .filter(g => g.id !== id && !childIds.includes(g.id))
        .map(g => `<option value="${g.id}">${escapeHtml(g.name)}</option>`)
        .join('');

    new bootstrap.Modal(document.getElementById('relationModal')).show();
}

function renderChildrenList(children, parentId) {
    const list = document.getElementById('child-goals-list');
    if (children.length === 0) {
        list.innerHTML = '<p class="text-muted">暂无关联子目标</p>';
        return;
    }
    list.innerHTML = children.map(g =>
        `<div class="list-group-item d-flex justify-content-between align-items-center">
            ${escapeHtml(g.name)}
            <button class="btn btn-sm btn-outline-danger" onclick="removeChildRelation(${parentId}, ${g.id})">
                <i class="bi bi-trash"></i> 移除
            </button>
        </div>`
    ).join('');
}

async function addSelectedChildren() {
    const parentId = document.getElementById('relation-goal-id').value;
    const select = document.getElementById('available-goals-select');
    const selectedOptions = Array.from(select.selectedOptions);

    if (selectedOptions.length === 0) {
        alert('请先选择要添加的子目标');
        return;
    }

    for (const option of selectedOptions) {
        const childId = parseInt(option.value);
        try {
            const res = await fetch(`${API_BASE}/${parentId}/children`, {
                method: 'POST',
                headers: {'Content-Type': 'application/json'},
                body: JSON.stringify({child_goal_id: childId})
            });
            if (!res.ok) {
                const err = await res.json();
                alert(err.error || '添加失败');
            }
        } catch (e) {
            console.error(e);
        }
    }

    // 刷新列表
    const children = await fetch(`${API_BASE}/${parentId}/children`).then(r => r.json());
    renderChildrenList(children, parentId);

    // 从下拉框移除已添加的
    selectedOptions.forEach(opt => opt.remove());
}

async function removeChildRelation(parentId, childId) {
    if (!confirm('确定移除此关联？')) return;
    await fetch(`${API_BASE}/${parentId}/children/${childId}`, {method: 'DELETE'});

    // 刷新列表
    const children = await fetch(`${API_BASE}/${parentId}/children`).then(r => r.json());
    renderChildrenList(children, parentId);

    // 刷新下拉框
    const allGoals = await fetch(API_BASE).then(r => r.json());
    const childIds = children.map(c => c.id);
    const select = document.getElementById('available-goals-select');
    const currentGoalId = parseInt(document.getElementById('relation-goal-id').value);
    select.innerHTML = allGoals
        .filter(g => g.id !== currentGoalId && !childIds.includes(g.id))
        .map(g => `<option value="${g.id}">${escapeHtml(g.name)}</option>`)
        .join('');
}

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

document.getElementById('save-goal').addEventListener('click', saveGoal);
document.getElementById('goalModal').addEventListener('hidden.bs.modal', () => {
    document.getElementById('goal-id').value = '';
    document.getElementById('goal-name').value = '';
    document.getElementById('goal-level').value = '入门';
    document.getElementById('goal-content').value = '';
    document.getElementById('goalModalTitle').textContent = '新建目标';
});

loadGoals();
</script>
{% endblock %}