<?php
/**
 * ajax/images.php
 *
 * Backs the Images panel.
 *
 * Actions (?action=...):
 *   list     GET  -> normalized image list
 *   pull     POST {"reference": "docker.io/library/postgres:16"}
 *   remove   POST {"id": "...", "force": false}
 *   prune    POST {} -> removes every image not used by any container
 *   tag      POST {"id": "...", "repo": "...", "tag": "latest"}
 */

declare(strict_types=1);

require __DIR__ . '/../include/bootstrap.php';

$action = $_GET['action'] ?? '';

switch ($action) {
    case 'list':
        podman_json_response(images_list($client));
        break;

    case 'pull':
        $body = podman_read_json_body();
        $reference = (string) ($body['reference'] ?? '');
        if ($reference === '') {
            podman_json_error('Missing reference in request body', 400);
        }
        podman_json_response($client->pullImage($reference));
        break;

    case 'remove':
        $body = podman_read_json_body();
        $id = (string) ($body['id'] ?? '');
        if ($id === '') {
            podman_json_error('Missing id in request body', 400);
        }
        $client->removeImage($id, (bool) ($body['force'] ?? false));
        podman_json_response(['status' => 'removed']);
        break;

    case 'prune':
        $removed = $client->pruneImages();
        $reclaimed = 0;
        foreach ($removed as $r) {
            $reclaimed += (int) ($r['Size'] ?? 0);
        }
        podman_json_response(['removedCount' => count($removed), 'reclaimedBytes' => $reclaimed]);
        break;

    case 'tag':
        $body = podman_read_json_body();
        $id = (string) ($body['id'] ?? '');
        $repo = trim((string) ($body['repo'] ?? ''));
        $tag = trim((string) ($body['tag'] ?? '')) ?: 'latest';
        if ($id === '' || $repo === '') {
            podman_json_error('Missing id or repo in request body', 400);
        }
        $client->tagImage($id, $repo, $tag);
        podman_json_response(['status' => 'tagged']);
        break;

    default:
        podman_json_error("Unknown action '{$action}'", 400);
}

/** @return array<int,array<string,mixed>> */
function images_list(PodmanClient $client): array
{
    $raw = $client->listImages();

    // In-use counts let the frontend show "0" (safe to remove) vs a
    // positive count, without a separate round trip per image.
    $usageCounts = [];
    foreach ($client->listContainers(true) as $c) {
        $imageId = (string) ($c['ImageID'] ?? '');
        if ($imageId !== '') {
            $usageCounts[$imageId] = ($usageCounts[$imageId] ?? 0) + 1;
        }
    }

    $out = [];
    foreach ($raw as $img) {
        $id = (string) ($img['Id'] ?? '');
        $repoTags = $img['RepoTags'] ?? [];
        $repository = '<none>';
        $tag = '<none>';
        if (is_array($repoTags) && count($repoTags) > 0 && is_string($repoTags[0]) && str_contains($repoTags[0], ':')) {
            [$repository, $tag] = explode(':', $repoTags[0], 2);
        }

        $out[] = [
            'id' => $id,
            'shortId' => podman_short_id($id),
            'repository' => $repository,
            'tag' => $tag,
            'sizeBytes' => (int) ($img['Size'] ?? 0),
            'sizeFormatted' => podman_format_bytes((int) ($img['Size'] ?? 0)),
            // Unlike containers' Created/StartedAt (RFC3339 strings), libpod
            // reports image Created as a Unix timestamp integer directly.
            'createdAt' => isset($img['Created']) ? (int) $img['Created'] : null,
            'usedBy' => $usageCounts[$id] ?? 0,
        ];
    }

    usort($out, static fn($a, $b) => strcmp($a['repository'], $b['repository']));
    return $out;
}