<?php
require_once __DIR__ . '/config.php';
session_start_safe();

if (empty($_SESSION['access_token']) || (($_SESSION['token_expires'] ?? 0) <= time())) {
    header('Location: ' . auth_start_href(current_return_path()));
    exit;
}

$user = current_fflogs_user();
if (!$user) {
    http_response_code(502);
}

$allowed = $user && is_admin_user();
if (!$allowed && $user) {
    http_response_code(403);
}

if (empty($_SESSION['admin_csrf'])) {
    $_SESSION['admin_csrf'] = bin2hex(random_bytes(16));
}
$csrf = $_SESSION['admin_csrf'];
$returnPath = safe_return_path($_GET['return'] ?? null);
$adminAction = 'admin.php?return=' . rawurlencode($returnPath);

function admin_h(?string $value): string {
    return htmlspecialchars((string)$value, ENT_QUOTES | ENT_SUBSTITUTE, 'UTF-8');
}

function git_run(array $args): array {
    $cmd = 'git -C ' . escapeshellarg(__DIR__);
    foreach ($args as $arg) {
        $cmd .= ' ' . escapeshellarg($arg);
    }
    $cmd .= ' 2>&1';
    exec($cmd, $lines, $code);
    return ['code' => $code, 'output' => trim(implode("\n", $lines))];
}

function git_output(array $args): string {
    return git_run($args)['output'];
}

function git_local_branches(): array {
    $out = git_output(['branch', '--list', '--no-color']);
    $branches = array_values(array_filter(array_map(function ($line) {
        return trim(ltrim(trim($line), '*'));
    }, explode("\n", $out)), fn($v) => $v !== ''));
    sort($branches, SORT_NATURAL | SORT_FLAG_CASE);
    return $branches;
}

function git_remote_branches(): array {
    $out = git_output(['branch', '-r', '--no-color']);
    $branches = array_values(array_filter(array_map('trim', explode("\n", $out)), function ($branch) {
        return $branch !== '' && !str_contains($branch, ' -> ') && !str_ends_with($branch, '/HEAD');
    }));
    sort($branches, SORT_NATURAL | SORT_FLAG_CASE);
    return $branches;
}

function branch_from_remote(string $remoteBranch): string {
    $parts = explode('/', $remoteBranch, 2);
    return $parts[1] ?? $remoteBranch;
}

function git_last_commit(): string {
    $out = git_output(['log', '-1', '--oneline', '--decorate=short']);
    return $out !== '' ? $out : '(unknown)';
}

function git_current_branch(): string {
    return git_output(['rev-parse', '--abbrev-ref', 'HEAD']);
}

function git_upstream_for_branch(string $branch): ?string {
    $result = git_run(['rev-parse', '--abbrev-ref', $branch . '@{upstream}']);
    return $result['code'] === 0 && $result['output'] !== '' ? $result['output'] : null;
}

function git_is_ancestor(string $ancestor, string $descendant): bool {
    return git_run(['merge-base', '--is-ancestor', $ancestor, $descendant])['code'] === 0;
}

function git_pull_all_tracked_branches(): array {
    $lines = [];
    $exitCode = 0;

    $fetch = git_run(['fetch', '--all', '--prune']);
    $lines[] = '$ git fetch --all --prune';
    $lines[] = $fetch['output'] ?: '(no output)';
    if ($fetch['code'] !== 0) return ['code' => $fetch['code'], 'output' => implode("\n", $lines)];

    $current = git_current_branch();
    foreach (git_local_branches() as $branch) {
        $upstream = git_upstream_for_branch($branch);
        if ($upstream === null) {
            $lines[] = '';
            $lines[] = $branch . ': no upstream configured, skipped';
            continue;
        }

        $lines[] = '';
        $lines[] = $branch . ' <- ' . $upstream;
        if ($branch === $current) {
            $pull = git_run(['merge', '--ff-only', $upstream]);
            $lines[] = '$ git merge --ff-only ' . $upstream;
            $lines[] = $pull['output'] ?: '(no output)';
            if ($pull['code'] !== 0) $exitCode = $pull['code'];
            continue;
        }

        if (git_is_ancestor($branch, $upstream)) {
            $update = git_run(['branch', '-f', $branch, $upstream]);
            $lines[] = '$ git branch -f ' . $branch . ' ' . $upstream;
            $lines[] = $update['output'] ?: '(fast-forwarded)';
            if ($update['code'] !== 0) $exitCode = $update['code'];
        } elseif (git_is_ancestor($upstream, $branch)) {
            $lines[] = 'already up to date or ahead';
        } else {
            $lines[] = 'diverged, skipped';
            if ($exitCode === 0) $exitCode = 1;
        }
    }

    return ['code' => $exitCode, 'output' => implode("\n", $lines)];
}

function resolve_selected_branch_ref(string $ref, array $localBranches, array $remoteBranches, bool $preferLocalForRemote): ?string {
    if (str_starts_with($ref, 'local:')) {
        $branch = substr($ref, 6);
        return in_array($branch, $localBranches, true) ? $branch : null;
    }

    if (str_starts_with($ref, 'remote:')) {
        $remoteBranch = substr($ref, 7);
        if (!in_array($remoteBranch, $remoteBranches, true)) return null;
        $localBranch = branch_from_remote($remoteBranch);
        return $preferLocalForRemote && in_array($localBranch, $localBranches, true) ? $localBranch : $remoteBranch;
    }

    return null;
}

$message = null;
$result = null;

if ($allowed && $_SERVER['REQUEST_METHOD'] === 'POST') {
    if (!hash_equals($csrf, $_POST['csrf'] ?? '')) {
        http_response_code(400);
        $message = 'Invalid CSRF token.';
    } else {
        $action = $_POST['action'] ?? '';
        if ($action === 'fetch') {
            $result = git_run(['fetch', '--all', '--prune']);
            $message = 'git fetch --all --prune';
        } elseif ($action === 'pull') {
            $result = git_pull_all_tracked_branches();
            $message = 'pull all tracked branches';
        } elseif ($action === 'push') {
            $result = git_run(['push']);
            $message = 'git push';
        } elseif ($action === 'commit') {
            $commitMessage = trim((string)($_POST['message'] ?? ''));
            if ($commitMessage === '') {
                $result = ['code' => 1, 'output' => 'Commit message is required.'];
            } else {
                $add = git_run(['add', '-A']);
                if ($add['code'] !== 0) {
                    $result = $add;
                    $message = 'git add -A';
                } else {
                    $result = git_run(['commit', '-m', $commitMessage]);
                    $message = 'git commit';
                }
            }
        } elseif ($action === 'merge') {
            $ref = trim((string)($_POST['merge_branch'] ?? ''));
            git_run(['fetch', '--all', '--prune']);
            $localBranches = git_local_branches();
            $remoteBranches = git_remote_branches();
            $branch = resolve_selected_branch_ref($ref, $localBranches, $remoteBranches, false);
            if ($branch === null) {
                $result = ['code' => 1, 'output' => 'Unknown branch selection.'];
            } else {
                $result = git_run(['merge', '--no-edit', $branch]);
                $message = 'git merge --no-edit ' . $branch;
            }
        } elseif ($action === 'switch') {
            $ref = trim((string)($_POST['branch'] ?? ''));
            $localBranches = git_local_branches();
            $remoteBranches = git_remote_branches();
            if (str_starts_with($ref, 'remote:')) {
                $remoteBranch = substr($ref, 7);
                if (!in_array($remoteBranch, $remoteBranches, true)) {
                    $result = ['code' => 1, 'output' => 'Unknown remote branch: ' . $remoteBranch];
                } else {
                    $branch = branch_from_remote($remoteBranch);
                    if (in_array($branch, $localBranches, true)) {
                        $result = git_run(['switch', $branch]);
                        $message = 'git switch ' . $branch;
                    } else {
                        $result = git_run(['switch', '--track', $remoteBranch]);
                        $message = 'git switch --track ' . $remoteBranch;
                    }
                }
            } else {
                $branch = resolve_selected_branch_ref($ref, $localBranches, $remoteBranches, true);
                if ($branch === null) {
                    $result = ['code' => 1, 'output' => 'Unknown branch selection.'];
                } else {
                    $result = git_run(['switch', $branch]);
                    $message = 'git switch ' . $branch;
                }
            }
        }
    }
}

$currentBranch = '';
$status = '';
$branches = [];
$remoteBranches = [];
$lastCommit = '';
if ($allowed) {
    $currentBranch = git_current_branch();
    $status = git_output(['status', '-sb']);
    $branches = git_local_branches();
    $remoteBranches = git_remote_branches();
    $lastCommit = git_last_commit();
}
?>
<!DOCTYPE html>
<html lang="de">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Admin · FFLogs Report Viewer</title>
  <link rel="stylesheet" href="css/base.css">
  <link rel="stylesheet" href="css/layout.css">
  <link rel="stylesheet" href="css/components.css">
  <style>
    .admin-shell { max-width: 980px; margin: 24px auto; width: min(92%, 980px); }
    .admin-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; align-items: start; }
    .admin-actions { display: flex; gap: 10px; flex-wrap: wrap; align-items: end; }
    .admin-pre {
      background: var(--bg2);
      border: 1px solid var(--border);
      border-radius: var(--r);
      padding: 14px;
      overflow: auto;
      white-space: pre-wrap;
      color: var(--t2);
      font-size: 13px;
      line-height: 1.5;
    }
    .admin-meta { color: var(--t2); line-height: 1.8; font-size: 14px; }
    .admin-deny { max-width: 720px; margin: 24px auto; width: min(92%, 720px); }
    @media (max-width: 800px) { .admin-grid { grid-template-columns: 1fr; } }
  </style>
</head>
<body>
<div id="app">
  <header id="topbar">
    <a class="logo" href="<?= admin_h($returnPath) ?>" style="text-decoration:none">REPORT VIEWER <span>Admin</span></a>
    <div class="topbar-actions">
      <a class="topbar-link" href="<?= admin_h($returnPath) ?>">Back</a>
      <div class="topbar-user">
        <?= $user ? admin_h($user['name'] ?: 'FFLogs User') . ' #' . admin_h($user['id']) : 'FFLogs user unavailable' ?>
      </div>
    </div>
  </header>

  <?php if (!$user): ?>
    <main class="admin-deny">
      <div class="card">
        <div class="card-title">User nicht verfügbar</div>
        <p class="admin-meta">Ich konnte deine FFLogs User-ID nicht laden. <?= admin_h($_SESSION['fflogs_user_error'] ?? '') ?></p>
      </div>
    </main>
  <?php elseif (!$allowed): ?>
    <main class="admin-deny">
      <div class="card">
        <div class="card-title">Kein Zugriff</div>
        <p class="admin-meta">
          Deine FFLogs User-ID ist <strong><?= admin_h($user['id']) ?></strong>.
          Füge diese ID in deiner <code>.env</code> zu <code>ADMIN_USER_IDS</code> hinzu, um diese Seite freizuschalten.
        </p>
      </div>
    </main>
  <?php else: ?>
    <main class="admin-shell">
      <div class="card">
        <div class="card-title">Git Admin</div>
        <div class="admin-meta">
          Branch: <strong><?= admin_h($currentBranch) ?></strong><br>
          Last commit: <?= admin_h($lastCommit) ?>
        </div>
      </div>

      <div class="admin-grid section-gap">
        <div class="card">
          <div class="card-title">Aktionen</div>
          <form method="post" action="<?= admin_h($adminAction) ?>" class="admin-actions">
            <input type="hidden" name="csrf" value="<?= admin_h($csrf) ?>">
            <button class="btn" name="action" value="fetch" type="submit">Fetch</button>
            <button class="btn btn-gold" name="action" value="pull" type="submit">Pull All</button>
            <button class="btn" name="action" value="push" type="submit">Push</button>
          </form>

          <form method="post" action="<?= admin_h($adminAction) ?>" class="admin-actions section-gap">
            <input type="hidden" name="csrf" value="<?= admin_h($csrf) ?>">
            <input type="hidden" name="action" value="switch">
            <div class="fg">
              <label for="branch">Branch</label>
              <select id="branch" name="branch">
                <?php foreach ($branches as $branch): ?>
                  <option value="local:<?= admin_h($branch) ?>" <?= $branch === $currentBranch ? 'selected' : '' ?>>
                    <?= admin_h($branch) ?>
                  </option>
                <?php endforeach; ?>
                <?php if ($remoteBranches): ?>
                  <optgroup label="Remote branches">
                    <?php foreach ($remoteBranches as $branch): ?>
                      <option value="remote:<?= admin_h($branch) ?>">
                        <?= admin_h($branch) ?>
                      </option>
                    <?php endforeach; ?>
                  </optgroup>
                <?php endif; ?>
              </select>
            </div>
            <button class="btn" type="submit">Switch</button>
          </form>

          <form method="post" action="<?= admin_h($adminAction) ?>" class="section-gap">
            <input type="hidden" name="csrf" value="<?= admin_h($csrf) ?>">
            <input type="hidden" name="action" value="commit">
            <div class="fg">
              <label for="commit-message">Commit message</label>
              <input id="commit-message" name="message" type="text" placeholder="Describe the change…" required>
            </div>
            <button class="btn btn-gold section-gap" type="submit">Commit all changes</button>
          </form>

          <form method="post" action="<?= admin_h($adminAction) ?>" class="admin-actions section-gap">
            <input type="hidden" name="csrf" value="<?= admin_h($csrf) ?>">
            <input type="hidden" name="action" value="merge">
            <div class="fg">
              <label for="merge-branch">Merge from branch</label>
              <select id="merge-branch" name="merge_branch">
                <?php foreach ($branches as $branch): ?>
                  <?php if ($branch === $currentBranch) continue; ?>
                  <option value="local:<?= admin_h($branch) ?>">
                    <?= admin_h($branch) ?>
                  </option>
                <?php endforeach; ?>
                <?php if ($remoteBranches): ?>
                  <optgroup label="Remote branches">
                    <?php foreach ($remoteBranches as $branch): ?>
                      <option value="remote:<?= admin_h($branch) ?>">
                        <?= admin_h($branch) ?>
                      </option>
                    <?php endforeach; ?>
                  </optgroup>
                <?php endif; ?>
              </select>
            </div>
            <button class="btn" type="submit">Merge</button>
          </form>
        </div>

        <div class="card">
          <div class="card-title">Status</div>
          <pre class="admin-pre"><?= admin_h($status ?: 'Clean') ?></pre>
        </div>
      </div>

      <?php if ($result): ?>
        <div class="card section-gap">
          <div class="card-title"><?= admin_h($message ?? 'Output') ?> · Exit <?= (int)$result['code'] ?></div>
          <pre class="admin-pre"><?= admin_h($result['output'] ?: '(no output)') ?></pre>
        </div>
      <?php endif; ?>
    </main>
  <?php endif; ?>
</div>
</body>
</html>