<?php
/**
 * WEVIA Obsidian Vault API — Sovereign Memory Layer
 * Replaces 3000+ tokens of userMemories with on-demand search
 * Endpoint: /api/wevia-vault.php
 */
header('Content-Type: application/json');
$VAULT = '/opt/obsidian-vault';
$action = $_GET['action'] ?? $_POST['action'] ?? 'search';
$q = $_GET['q'] ?? $_POST['q'] ?? '';

switch ($action) {
    case 'search':
        if (!$q) { echo json_encode(['error' => 'no query']); exit; }
        $results = [];
        $iter = new RecursiveIteratorIterator(new RecursiveDirectoryIterator($VAULT));
        foreach ($iter as $file) {
            if ($file->getExtension() !== 'md') continue;
            $content = file_get_contents($file->getPathname());
            if (stripos($content, $q) !== false) {
                $rel = str_replace($VAULT . '/', '', $file->getPathname());
                // Extract frontmatter tags
                preg_match('/tags:\s*\[([^\]]+)\]/', $content, $tm);
                $results[] = [
                    'file' => $rel,
                    'tags' => trim($tm[1] ?? ''),
                    'snippet' => substr(strip_tags($content), 0, 200),
                    'size' => strlen($content)
                ];
            }
        }
        echo json_encode(['query' => $q, 'results' => $results, 'count' => count($results)]);
        break;

    case 'read':
        $file = $_GET['file'] ?? '';
        $path = realpath($VAULT . '/' . $file);
        if (!$path || strpos($path, $VAULT) !== 0 || !file_exists($path)) {
            echo json_encode(['error' => 'file not found']); exit;
        }
        echo json_encode(['file' => $file, 'content' => file_get_contents($path), 'size' => filesize($path)]);
        break;

    case 'list':
        $dir = $_GET['dir'] ?? '';
        $target = realpath($VAULT . '/' . $dir) ?: $VAULT;
        if (strpos($target, $VAULT) !== 0) { echo json_encode(['error' => 'invalid path']); exit; }
        $files = [];
        foreach (scandir($target) as $f) {
            if ($f[0] === '.') continue;
            $full = $target . '/' . $f;
            $files[] = ['name' => $f, 'type' => is_dir($full) ? 'dir' : 'file', 'size' => is_file($full) ? filesize($full) : 0];
        }
        echo json_encode(['dir' => $dir ?: '/', 'files' => $files, 'count' => count($files)]);
        break;

    case 'write':
        $file = $_POST['file'] ?? '';
        $content = $_POST['content'] ?? '';
        if (!$file || !$content) { echo json_encode(['error' => 'file and content required']); exit; }
        $path = $VAULT . '/' . $file;
        $dir = dirname($path);
        if (!is_dir($dir)) mkdir($dir, 0755, true);
        file_put_contents($path, $content);
        echo json_encode(['ok' => true, 'file' => $file, 'size' => strlen($content)]);
        break;

    case 'stats':
        $count = 0; $total = 0; $dirs = [];
        $iter = new RecursiveIteratorIterator(new RecursiveDirectoryIterator($VAULT));
        foreach ($iter as $f) {
            if ($f->getExtension() === 'md') { $count++; $total += $f->getSize(); }
        }
        foreach (scandir($VAULT) as $d) {
            if ($d[0] !== '.' && is_dir("$VAULT/$d")) {
                $n = count(glob("$VAULT/$d/*.md"));
                $dirs[] = ['name' => $d, 'files' => $n];
            }
        }
        echo json_encode(['vault' => $VAULT, 'files' => $count, 'total_bytes' => $total, 'bytes' => $total, 'size' => $total, 'size_kb' => round($total/1024), 'size_human' => $total >= 1048576 ? round($total/1048576,1).' MB' : round($total/1024).' KB', 'dirs' => $dirs]);
        break;

    default:
        echo json_encode(['error' => 'unknown action', 'actions' => ['search','read','list','write','stats']]);
}