<?php
$parent_id = $_GET['folder'] ?? null;

if($_SERVER['REQUEST_METHOD'] === 'POST' && isset($_POST['create_folder'])) {
    $stmt = $pdo->prepare("INSERT INTO projects (name, is_folder, parent_id, owner_id) VALUES (?, 1, ?, ?)");
    $stmt->execute([$_POST['name'], $parent_id, $user_id]);
}

if($_SERVER['REQUEST_METHOD'] === 'POST' && isset($_POST['delete_item'])) {
    $stmt = $pdo->prepare("DELETE FROM projects WHERE id=? AND owner_id=?");
    $stmt->execute([$_POST['item_id'], $user_id]);
}

if($_SERVER['REQUEST_METHOD'] === 'POST' && isset($_POST['edit_item'])) {
    $stmt = $pdo->prepare("UPDATE projects SET name=? WHERE id=? AND owner_id=?");
    $stmt->execute([$_POST['new_name'], $_POST['item_id'], $user_id]);
}

if($_SERVER['REQUEST_METHOD'] === 'POST' && isset($_POST['upload_file']) && isset($_FILES['file'])) {
    $name = $_FILES['file']['name'];
    $tmp_name = $_FILES['file']['tmp_name'];
    $size = $_FILES['file']['size'];
    $path = 'uploads/' . time() . '_' . $name;
    move_uploaded_file($tmp_name, $path);
    $stmt = $pdo->prepare("INSERT INTO projects (name, is_folder, parent_id, file_path, owner_id) VALUES (?, 0, ?, ?, ?)");
    $stmt->execute([$name, $parent_id, $path, $user_id]);
    echo "OK"; exit;
}

if($_SERVER['REQUEST_METHOD'] === 'POST' && isset($_POST['share_project'])) {
    $pr_id = $_POST['project_id'];
    $share = $_POST['share_target'];
    $parts = explode('_', $share, 2);
    if(count($parts)===2) {
        $stmt = $pdo->prepare("INSERT INTO project_shares (project_id, share_type, share_id) VALUES (?, ?, ?)");
        $stmt->execute([$pr_id, $parts[0], $parts[1]]);
        $pr = query("SELECT name FROM projects WHERE id=?", [$pr_id])->fetch();
        $msg = "A project/file '{$pr['name']}' has been shared with you.";
        if($parts[0] === 'user') notify_user($parts[1], $msg);
        else notify_group($parts[1], $msg);
    }
}

// ── Fetch current folder content ──────────────────────────────────────────────
$user_groups = get_user_groups($user_id);
$my_group_ids = array_column($user_groups, 'id');
$group_in = implode(',', array_fill(0, count($my_group_ids), '?')) ?: '0';

$parent_cond = $parent_id ? "p.parent_id = ?" : "p.parent_id IS NULL";
$sql = "SELECT p.*, (p.owner_id = ?) as is_mine, u.username as owner_name FROM projects p 
        LEFT JOIN project_shares ps ON p.id = ps.project_id 
        LEFT JOIN users u ON p.owner_id = u.id
        WHERE ($parent_cond) AND (
            p.owner_id = ? 
            OR (ps.share_type='user' AND ps.share_id = ?) 
            OR (ps.share_type='group' AND ps.share_id IN ($group_in))
        ) GROUP BY p.id ORDER BY p.is_folder DESC, p.name ASC";

$params = [$user_id];
if($parent_id) $params[] = $parent_id;
$params = array_merge($params, [$user_id, $user_id], $my_group_ids);

$stmt = $pdo->prepare($sql);
$stmt->execute($params);
$items = $stmt->fetchAll();

$all_users = query("SELECT id, username FROM users WHERE id != ?", [$user_id])->fetchAll();
$all_groups = query("SELECT * FROM groups")->fetchAll();

// ── Build breadcrumb path ─────────────────────────────────────────────────────
$breadcrumbs = [];
$cur_id = $parent_id;
while($cur_id) {
    $node = query("SELECT id, name, parent_id FROM projects WHERE id=?", [$cur_id])->fetch();
    if(!$node) break;
    array_unshift($breadcrumbs, $node);
    $cur_id = $node['parent_id'];
}

// ── Helper: file size ─────────────────────────────────────────────────────────
function fmt_size($bytes) {
    if(!$bytes) return '—';
    if($bytes < 1024) return $bytes . ' B';
    if($bytes < 1048576) return round($bytes/1024,1) . ' KB';
    return round($bytes/1048576,1) . ' MB';
}
function get_file_icon($name, $is_folder) {
    if($is_folder) return '📁';
    $ext = strtolower(pathinfo($name, PATHINFO_EXTENSION));
    $map = [
        'pdf'=>'📄','doc'=>'📝','docx'=>'📝','xls'=>'📊','xlsx'=>'📊','ppt'=>'📑','pptx'=>'📑',
        'jpg'=>'🖼','jpeg'=>'🖼','png'=>'🖼','gif'=>'🖼','webp'=>'🖼','svg'=>'🖼',
        'mp4'=>'🎬','avi'=>'🎬','mov'=>'🎬','mp3'=>'🎵','wav'=>'🎵',
        'zip'=>'🗜','rar'=>'🗜','7z'=>'🗜','tar'=>'🗜',
        'php'=>'⚙','js'=>'⚙','css'=>'🎨','html'=>'🌐','txt'=>'📃','md'=>'📃',
        'sh'=>'💻','py'=>'🐍',
    ];
    return $map[$ext] ?? '📄';
}
?>

<!-- Rename form -->
<form method="POST" id="rename-form" style="display:none;">
    <input type="hidden" name="edit_item" value="1">
    <input type="hidden" name="item_id" id="rn-item_id">
    <input type="hidden" name="new_name" id="rn-new_name">
</form>

<!-- Share Modal -->
<div class="modal-overlay" id="share-modal">
    <div class="modal-content" style="max-width:400px;">
        <h3 style="margin-bottom:1rem; font-size:1.05rem;"><i class="fa fa-share-nodes"></i> Share Item</h3>
        <form method="POST" id="share-form">
            <input type="hidden" name="share_project" value="1">
            <input type="hidden" name="project_id" id="share-project-id">
            <div class="form-group">
                <label>Share with</label>
                <select name="share_target" class="form-control">
                    <?php foreach($all_users as $u): ?>
                        <option value="user_<?= $u['id'] ?>">👤 <?= htmlspecialchars($u['username']) ?></option>
                    <?php endforeach; ?>
                    <?php foreach($all_groups as $g): ?>
                        <option value="group_<?= $g['id'] ?>">👥 <?= htmlspecialchars($g['name']) ?></option>
                    <?php endforeach; ?>
                </select>
            </div>
            <div style="display:flex; gap:0.5rem; justify-content:flex-end; margin-top:1rem;">
                <button type="button" class="btn btn-secondary" onclick="document.getElementById('share-modal').classList.remove('active')">Cancel</button>
                <button type="submit" class="btn"><i class="fa fa-share-nodes"></i> Share</button>
            </div>
        </form>
    </div>
</div>

<!-- Delete form -->
<form method="POST" id="delete-item-form" style="display:none;">
    <input type="hidden" name="delete_item" value="1">
    <input type="hidden" name="item_id" id="delete-item-id">
</form>

<div class="header" style="margin-bottom:0.75rem;">
    <h1 style="font-size:1.5rem; font-weight:700;">📁 Project Explorer</h1>
    <div style="display:flex; gap:0.5rem; flex-wrap:wrap;">
        <label class="btn btn-secondary" style="cursor:pointer;">
            <i class="fa fa-arrow-up-from-bracket"></i> Upload File
            <input type="file" id="file-upload-input" style="display:none;" onchange="handleFileSelect(this)">
        </label>
        <button class="btn" onclick="showNewFolderDialog()"><i class="fa fa-folder-plus"></i> New Folder</button>
    </div>
</div>

<!-- Hidden folder create form -->
<form method="POST" id="new-folder-form" style="display:none;">
    <input type="hidden" name="create_folder" value="1">
    <input type="hidden" name="name" id="new-folder-name">
</form>

<!-- Explorer Toolbar / Breadcrumb -->
<div class="explorer-toolbar">
    <a href="?action=projects" class="btn btn-secondary btn-sm" title="Home">
        <i class="fa fa-house"></i>
    </a>
    <a href="javascript:history.back()" class="btn btn-secondary btn-sm" title="Back">
        <i class="fa fa-arrow-left"></i>
    </a>
    <div class="explorer-path">
        <a class="explorer-path-part <?= !$parent_id?'current':'' ?>" href="?action=projects">Root</a>
        <?php foreach($breadcrumbs as $bc): ?>
            <span class="explorer-path-sep">›</span>
            <a class="explorer-path-part <?= $bc['id']==$parent_id?'current':'' ?>" href="?action=projects&folder=<?= $bc['id'] ?>">
                <?= htmlspecialchars($bc['name']) ?>
            </a>
        <?php endforeach; ?>
    </div>

    <!-- Search -->
    <input type="text" id="explorer-search" placeholder="Search..." class="form-control" style="width:180px; padding:0.4rem 0.6rem; font-size:0.85rem;" oninput="filterExplorer(this.value)">
</div>

<!-- Drop Zone -->
<div id="dropzone" class="dropzone" style="padding:1.5rem; margin-bottom:0.75rem;"
    ondragover="this.classList.add('dragover'); return false;" 
    ondragleave="this.classList.remove('dragover');" 
    ondrop="handleDrop(event)">
    <i class="fa fa-cloud-arrow-up" style="font-size:1.5rem; margin-bottom:0.5rem; display:block;"></i>
    Drag & drop files here to upload
</div>

<!-- Detail Table -->
<div class="card" style="padding:0; overflow:hidden;">
    <table class="explorer-table" id="explorer-table">
        <thead>
            <tr>
                <th style="width:30px;"><input type="checkbox" id="explorer-select-all" onclick="explorerSelectAll(this)"></th>
                <th onclick="sortExplorer('name')" style="min-width:200px;">
                    <i class="fa fa-sort" style="font-size:0.7rem; margin-right:4px;"></i>Name
                </th>
                <th onclick="sortExplorer('type')" style="width:80px;">Type</th>
                <th onclick="sortExplorer('owner')" style="width:120px;">Owner</th>
                <th onclick="sortExplorer('size')" style="width:80px;">Size</th>
                <th style="width:140px;">Shared</th>
                <th style="width:160px; text-align:right;">Actions</th>
            </tr>
        </thead>
        <tbody id="explorer-tbody">
            <?php if(empty($items)): ?>
            <tr><td colspan="7" style="text-align:center; padding:3rem; color:var(--text-light);">
                <i class="fa fa-folder-open" style="font-size:2rem; display:block; margin-bottom:0.5rem;"></i>
                This folder is empty.
            </td></tr>
            <?php endif; ?>
            <?php foreach($items as $item):
                $ext = $item['is_folder'] ? 'folder' : strtoupper(pathinfo($item['name'], PATHINFO_EXTENSION) ?: 'File');
                $size = (!$item['is_folder'] && $item['file_path'] && file_exists($item['file_path'])) ? filesize($item['file_path']) : null;
                $icon = get_file_icon($item['name'], $item['is_folder']);
            ?>
            <tr class="explorer-row" data-name="<?= htmlspecialchars($item['name']) ?>" data-type="<?= $item['is_folder']?'folder':'file' ?>">
                <td><input type="checkbox" class="explorer-check" value="<?= $item['id'] ?>"></td>
                <td>
                    <div class="explorer-name">
                        <span class="explorer-icon"><?= $icon ?></span>
                        <?php if($item['is_folder']): ?>
                            <a href="?action=projects&folder=<?= $item['id'] ?>"><?= htmlspecialchars($item['name']) ?></a>
                        <?php else: ?>
                            <a href="<?= htmlspecialchars($item['file_path']) ?>" target="_blank"><?= htmlspecialchars($item['name']) ?></a>
                        <?php endif; ?>
                    </div>
                </td>
                <td style="color:var(--text-light); font-size:0.8rem;"><?= htmlspecialchars($ext) ?></td>
                <td style="font-size:0.8rem;">
                    <?= htmlspecialchars($item['owner_name']) ?>
                    <?php if(!$item['is_mine']): ?><span class="badge" style="font-size:0.6rem; padding:1px 5px; margin-left:2px;">Shared</span><?php endif; ?>
                </td>
                <td style="color:var(--text-light); font-size:0.8rem;"><?= $size !== null ? fmt_size($size) : '—' ?></td>
                <td style="font-size:0.8rem; color:var(--text-light);">
                    <?php
                    // Show shares
                    $shares = query("SELECT ps.share_type, ps.share_id, u.username, g.name as gname FROM project_shares ps LEFT JOIN users u ON (ps.share_type='user' AND ps.share_id=u.id) LEFT JOIN groups g ON (ps.share_type='group' AND ps.share_id=g.id) WHERE ps.project_id=?", [$item['id']])->fetchAll();
                    foreach($shares as $sh) {
                        echo '<span style="font-size:0.72rem; background:rgba(var(--primary-rgb),0.1); color:var(--primary); padding:1px 5px; border-radius:8px; margin:1px; display:inline-block;">';
                        echo $sh['share_type']==='user' ? ('👤 '.htmlspecialchars($sh['username']??'')) : ('👥 '.htmlspecialchars($sh['gname']??''));
                        echo '</span>';
                    }
                    if(!$shares) echo '<span style="color:var(--text-light); font-size:0.8rem;">—</span>';
                    ?>
                </td>
                <td>
                    <div class="explorer-actions" style="justify-content:flex-end;">
                        <?php if($item['is_mine']): ?>
                        <button class="btn btn-sm btn-secondary" onclick="openShare(<?= $item['id'] ?>)" title="Share"><i class="fa fa-share-nodes"></i></button>
                        <button class="btn btn-sm btn-secondary" onclick="renameItem(<?= $item['id'] ?>, '<?= htmlspecialchars(addslashes($item['name'])) ?>')" title="Rename"><i class="fa fa-pen"></i></button>
                        <button class="btn btn-sm btn-danger" onclick="deleteItem(<?= $item['id'] ?>, '<?= htmlspecialchars(addslashes($item['name'])) ?>')" title="Delete"><i class="fa fa-trash"></i></button>
                        <?php else: ?>
                        <span style="font-size:0.75rem; color:var(--text-light); padding:0 0.5rem;">View only</span>
                        <?php endif; ?>
                    </div>
                </td>
            </tr>
            <?php endforeach; ?>
        </tbody>
    </table>
</div>

<!-- Status Bar -->
<div class="explorer-status-bar">
    <span id="explorer-count"><?= count($items) ?> item<?= count($items)!=1?'s':'' ?></span>
    <span id="explorer-selected-count" style="display:none; color:var(--primary); font-weight:600;"></span>
    <span style="margin-left:auto;">
        <?= $parent_id ? 'Folder: '.htmlspecialchars(end($breadcrumbs)['name'] ?? '') : 'Root directory' ?>
    </span>
</div>

<script>
function renameItem(id, currName) {
    let nn = prompt("Enter new name:", currName);
    if(nn && nn.trim()!=='' && nn !== currName) {
        document.getElementById('rn-item_id').value = id;
        document.getElementById('rn-new_name').value = nn;
        document.getElementById('rename-form').submit();
    }
}

function deleteItem(id, name) {
    if(!confirm(`Delete "${name}"? This cannot be undone.`)) return;
    document.getElementById('delete-item-id').value = id;
    document.getElementById('delete-item-form').submit();
}

function openShare(id) {
    document.getElementById('share-project-id').value = id;
    document.getElementById('share-modal').classList.add('active');
}

function showNewFolderDialog() {
    const name = prompt('New folder name:');
    if(name && name.trim()) {
        document.getElementById('new-folder-name').value = name.trim();
        document.getElementById('new-folder-form').submit();
    }
}

function handleFileSelect(input) {
    if(input.files.length > 0) uploadFile(input.files[0]);
}

function handleDrop(e) {
    e.preventDefault();
    e.currentTarget.classList.remove('dragover');
    if(e.dataTransfer.files.length > 0) uploadFile(e.dataTransfer.files[0]);
}

function uploadFile(file) {
    showToast('Uploading ' + file.name + '...');
    let formData = new FormData();
    formData.append('upload_file', '1');
    formData.append('file', file);
    fetch('?action=projects&folder=<?= $parent_id ?>', { method: 'POST', body: formData })
        .then(() => window.location.reload());
}

// ── Select all ────────────────────────────────────────────────────────────────
function explorerSelectAll(chk) {
    document.querySelectorAll('.explorer-check').forEach(c => c.checked = chk.checked);
    updateSelectedCount();
}
document.querySelectorAll('.explorer-check').forEach(c => c.addEventListener('change', updateSelectedCount));
function updateSelectedCount() {
    const n = document.querySelectorAll('.explorer-check:checked').length;
    const el = document.getElementById('explorer-selected-count');
    if(n > 0) {
        el.textContent = n + ' selected';
        el.style.display = 'inline';
    } else {
        el.style.display = 'none';
    }
}

// ── Search filter ─────────────────────────────────────────────────────────────
function filterExplorer(q) {
    q = q.toLowerCase();
    let visible = 0;
    document.querySelectorAll('#explorer-tbody tr.explorer-row').forEach(row => {
        const name = row.dataset.name || '';
        if(name.toLowerCase().includes(q)) { row.style.display = ''; visible++; }
        else row.style.display = 'none';
    });
    document.getElementById('explorer-count').textContent = visible + ' item' + (visible!==1?'s':'');
}

// ── Sort ──────────────────────────────────────────────────────────────────────
let sortDir = {};
function sortExplorer(col) {
    sortDir[col] = !sortDir[col];
    const tbody = document.getElementById('explorer-tbody');
    const rows = Array.from(tbody.querySelectorAll('tr.explorer-row'));
    rows.sort((a, b) => {
        let av = '', bv = '';
        if(col==='name')  { av=a.dataset.name||''; bv=b.dataset.name||''; }
        if(col==='type')  { av=a.dataset.type||''; bv=b.dataset.type||''; }
        // folders first for type sort
        if(col==='type' && av===bv) return 0;
        const cmp = av.localeCompare(bv);
        return sortDir[col] ? cmp : -cmp;
    });
    // Folders always first
    const folders = rows.filter(r => r.dataset.type==='folder');
    const files   = rows.filter(r => r.dataset.type!=='folder');
    [...folders,...files].forEach(r => tbody.appendChild(r));
}
</script>