<?php

declare(strict_types=1);

// Release storage and manifest handling.
//
// Two deliberate design decisions:
//  - the package filename prefix is configurable (MANAGE_PACKAGE_PREFIX)
//  - the package download URL is built from MANAGE_PUBLIC_URL instead of the
//    client-controlled Host header

require_once __DIR__ . "/bootstrap.php";

function manageReleaseReadManifest(): array
{
    $file = manageManifestFile();
    if (!is_file($file)) {
        return ["latest" => "", "releases" => []];
    }

    $decoded = manageReadJsonFile($file);

    return [
        "latest" => trim((string) ($decoded["latest"] ?? "")),
        "releases" => isset($decoded["releases"]) && is_array($decoded["releases"])
            ? $decoded["releases"]
            : [],
    ];
}

function manageReleaseWriteManifest(array $manifest): void
{
    manageEnsureDirectory(manageReleasesDir());
    manageWriteJsonFile(manageManifestFile(), [
        "latest" => (string) ($manifest["latest"] ?? ""),
        "releases" => isset($manifest["releases"]) && is_array($manifest["releases"])
            ? $manifest["releases"]
            : [],
    ]);
}

function manageReleasePackageFileName(string $version): string
{
    $prefix = trim((string) MANAGE_PACKAGE_PREFIX);
    if ($prefix === "") {
        $prefix = "release";
    }

    return $prefix . "-" . $version . ".zip";
}

function manageReleasePackagePath(string $packageRelativePath): ?string
{
    $packageRelativePath = trim($packageRelativePath);
    if (
        $packageRelativePath === "" ||
        str_contains($packageRelativePath, "\0") ||
        str_starts_with($packageRelativePath, "/")
    ) {
        return null;
    }

    $packagePath = realpath(manageReleasesDir() . $packageRelativePath);
    $packagesDir = realpath(managePackagesDir());
    if (
        $packagePath === false ||
        $packagesDir === false ||
        !str_starts_with($packagePath, rtrim($packagesDir, "/\\") . DIRECTORY_SEPARATOR) ||
        !is_file($packagePath)
    ) {
        return null;
    }

    return $packagePath;
}

// Absolute download URL handed to clients. Derived from the configured public
// URL so a forged Host header cannot redirect a client to another server.
function manageReleasePackageUrl(string $version): string
{
    $base = rtrim(trim((string) MANAGE_PUBLIC_URL), "/");
    if ($base === "") {
        throw new RuntimeException(
            "MANAGE_PUBLIC_URL ist nicht konfiguriert. Ohne diesen Wert kann keine Paket-URL erzeugt werden.",
        );
    }

    return $base . "/api/v1/package.php?version=" . rawurlencode($version);
}

function manageReleaseUploadedFileIsZip(array $file): bool
{
    $name = strtolower((string) ($file["name"] ?? ""));
    $tmpName = (string) ($file["tmp_name"] ?? "");

    if (!str_ends_with($name, ".zip") || !is_uploaded_file($tmpName)) {
        return false;
    }

    return manageFileIsZip($tmpName);
}

// Stores an uploaded package and publishes it as the new latest release.
// The checksum and size are always computed server-side; the publisher never
// supplies them.
function manageReleasePublishUpload(string $version, array $file): array
{
    $version = trim($version);
    if (!manageIsVersion($version)) {
        throw new RuntimeException("Version muss dem Format vX.Y.Z entsprechen.");
    }

    if (($file["error"] ?? UPLOAD_ERR_NO_FILE) !== UPLOAD_ERR_OK) {
        throw new RuntimeException(
            "Upload fehlgeschlagen (Fehlercode " . (string) ($file["error"] ?? "unbekannt") . ").",
        );
    }

    if (!manageReleaseUploadedFileIsZip($file)) {
        throw new RuntimeException("Die hochgeladene Datei muss ein ZIP-Paket sein.");
    }

    manageEnsureDirectory(managePackagesDir());

    $fileName = manageReleasePackageFileName($version);
    $targetPath = managePackagesDir() . $fileName;
    if (!move_uploaded_file((string) $file["tmp_name"], $targetPath)) {
        throw new RuntimeException("Das Paket konnte nicht gespeichert werden.");
    }

    @chmod($targetPath, 0664);

    $sha256 = strtolower(hash_file("sha256", $targetPath) ?: "");
    $size = filesize($targetPath);
    if (preg_match('/^[a-f0-9]{64}$/', $sha256) !== 1 || $size === false || $size <= 0) {
        @unlink($targetPath);
        throw new RuntimeException("Das gespeicherte Paket konnte nicht verifiziert werden.");
    }

    $manifest = manageReleaseReadManifest();
    $manifest["latest"] = $version;
    $manifest["releases"][$version] = [
        "version" => $version,
        "package" => "packages/" . $fileName,
        "sha256" => $sha256,
        "size" => $size,
        "published_at" => date(DATE_ATOM),
    ];

    uksort($manifest["releases"], static function (string $left, string $right): int {
        return version_compare(ltrim($left, "vV"), ltrim($right, "vV"));
    });
    manageReleaseWriteManifest($manifest);

    manageLogAccess("Release published", [
        "version" => $version,
        "size" => $size,
        "sha256" => $sha256,
    ]);

    return $manifest["releases"][$version];
}

function manageReleaseSetLatest(string $version): void
{
    $version = trim($version);
    if (!manageIsVersion($version)) {
        throw new RuntimeException("Ungültige Release-Version.");
    }

    $manifest = manageReleaseReadManifest();
    if (!isset($manifest["releases"][$version])) {
        throw new RuntimeException("Dieses Release ist nicht im Manifest vorhanden.");
    }

    $manifest["latest"] = $version;
    manageReleaseWriteManifest($manifest);

    manageLogAccess("Latest release changed", ["version" => $version]);
}

function manageReleaseDelete(string $version): void
{
    $version = trim($version);
    if (!manageIsVersion($version)) {
        throw new RuntimeException("Ungültige Release-Version.");
    }

    $manifest = manageReleaseReadManifest();
    if (!isset($manifest["releases"][$version])) {
        throw new RuntimeException("Dieses Release ist nicht im Manifest vorhanden.");
    }

    $package = trim((string) ($manifest["releases"][$version]["package"] ?? ""));
    unset($manifest["releases"][$version]);
    if ($manifest["latest"] === $version) {
        $manifest["latest"] = "";
    }

    manageReleaseWriteManifest($manifest);

    $packagePath = manageReleasePackagePath($package);
    if ($packagePath !== null) {
        @unlink($packagePath);
    }

    manageLogAccess("Release deleted", ["version" => $version]);
}

/**
 * Resolves one release into the payload a client receives. Every field is
 * re-validated here, because the manifest is the only thing standing between a
 * client and the code it will execute.
 *
 * @return array{version: string, package_url: string, sha256: string, size: int, published_at: string}
 */
function manageReleaseResolve(string $version): array
{
    $manifest = manageReleaseReadManifest();
    $releases = $manifest["releases"];

    if (!isset($releases[$version]) || !is_array($releases[$version])) {
        throw new RuntimeException("Release ist nicht konfiguriert.");
    }

    $release = $releases[$version];
    $releaseVersion = trim((string) ($release["version"] ?? $version));
    $sha256 = strtolower(trim((string) ($release["sha256"] ?? "")));
    $package = trim((string) ($release["package"] ?? ""));
    $size = isset($release["size"]) ? (int) $release["size"] : 0;
    $publishedAt = trim((string) ($release["published_at"] ?? ""));

    if ($releaseVersion !== $version || !manageIsVersion($releaseVersion)) {
        throw new RuntimeException("Release-Version ist ungültig.");
    }
    if (preg_match('/^[a-f0-9]{64}$/', $sha256) !== 1) {
        throw new RuntimeException("Release-Prüfsumme ist ungültig.");
    }

    $packagePath = manageReleasePackagePath($package);
    if ($packagePath === null) {
        throw new RuntimeException("Release-Paket fehlt.");
    }
    if (strtolower(pathinfo($packagePath, PATHINFO_EXTENSION)) !== "zip") {
        throw new RuntimeException("Release-Paket ist keine ZIP-Datei.");
    }

    if ($size <= 0) {
        $size = (int) (filesize($packagePath) ?: 0);
    }

    return [
        "version" => $releaseVersion,
        "package_path" => $packagePath,
        "package_url" => manageReleasePackageUrl($releaseVersion),
        "sha256" => $sha256,
        "size" => $size,
        "published_at" => $publishedAt,
    ];
}

function manageReleaseLatestVersion(): string
{
    $latest = manageReleaseReadManifest()["latest"];

    return manageIsVersion($latest) ? $latest : "";
}

// Releases newest first, for the admin UI.
function manageReleaseListDescending(): array
{
    $releases = manageReleaseReadManifest()["releases"];
    uksort($releases, static function (string $left, string $right): int {
        return version_compare(ltrim($right, "vV"), ltrim($left, "vV"));
    });

    return $releases;
}