import path from "node:path";

const env = process.env;

/**
 * parseInt with a default that distinguishes "unset" from "explicit 0".
 *
 * `min` clamps the result. Pass it for any value where 0 is not a coherent
 * setting — a pool of 0 workers, 0 concurrent jobs or a 0-second timeout
 * wedges or crashes the feature rather than disabling it. Values that fail
 * closed at 0 (byte caps) deliberately have no minimum.
 */
function intEnv(
    value: string | undefined,
    defaultValue: number,
    min = Number.NEGATIVE_INFINITY,
): number {
    if (value === undefined || value === "") return defaultValue;
    const parsed = parseInt(value, 10);
    return Number.isFinite(parsed) ? Math.max(min, parsed) : defaultValue;
}

const PORT = intEnv(env.PORT, 3000, 1);

const config = {
    OWNER_DISPLAY_NAME: env.OWNER_DISPLAY_NAME ?? "Admin",
    INLINE_MAX_BYTES: intEnv(env.INLINE_MAX_BYTES, 524288),
    MAX_UPLOAD_BYTES: intEnv(env.MAX_UPLOAD_BYTES, 10 * 1024 * 1024),
    MAX_USER_UPLOAD_BYTES: intEnv(env.MAX_USER_UPLOAD_BYTES, 2 * 1024 * 1024),
    TRUSTED_PROXY: !!env.TRUSTED_PROXY,
    RATE_LIMIT_DISABLED: !!env.RATE_LIMIT_DISABLED,
    SSH_DISABLED: !!env.SSH_DISABLED,
    SCANNED_REPO_PRIVATE:
        env.SCANNED_REPO_PRIVATE !== "0" &&
        env.SCANNED_REPO_PRIVATE !== "false",
    PORT,
    SSH_PORT: intEnv(env.SSH_PORT, 2222, 1),
    REGISTRATION_TYPE: (env.REGISTRATION_TYPE ?? "enabled") as
        | "enabled"
        | "disabled"
        | "queue",
    REGISTER_QUESTION: env.REGISTER_QUESTION ?? "",
    BASE_URL: env.BASE_URL ?? `http://localhost:${PORT}`,
    // Derived from BASE_URL after the literal closes (see below). Declared
    // here so consumers get a typed config object.
    PUBLIC_HTTPS: false,
    PUBLIC_ORIGIN: "",
    DATA_DIR: path.resolve(env.DATA_DIR ?? "./data"),
    HIGHLIGHT_WORKERS: intEnv(env.HIGHLIGHT_WORKERS, 4, 1),
    COMMITTER_NAME: env.COMMITTER_NAME ?? env.OWNER_DISPLAY_NAME ?? "Admin",
    COMMITTER_EMAIL: "",
    EXTRA_ALLOWED_SIGNERS_PATH: env.EXTRA_ALLOWED_SIGNERS_PATH ?? null,
    MAX_TITLE_BYTES: intEnv(env.MAX_TITLE_BYTES, 500),
    MAX_TEXT_BODY_BYTES: intEnv(env.MAX_TEXT_BODY_BYTES, 100_000),
    MAX_USERNAME_BYTES: intEnv(env.MAX_USERNAME_BYTES, 64),
    MAX_PASSWORD_BYTES: intEnv(env.MAX_PASSWORD_BYTES, 1024),
    CI_DOCKER_SOCKET: env.CI_DOCKER_SOCKET ?? "",
    CI_MAX_HISTORY: intEnv(env.CI_MAX_HISTORY, 50),
    CI_MAX_CONCURRENT: intEnv(env.CI_MAX_CONCURRENT, 2, 1),
    CI_DEFAULT_TIMEOUT: intEnv(env.CI_DEFAULT_TIMEOUT, 3600, 1),
    // Cap on simultaneous source archive generation jobs (one release with
    // include_source_code spawns three git-archive + compressor pipelines
    // back-to-back). Without this cap, an admin firing several releases in
    // quick succession can saturate CPU. Excess jobs are queued in memory.
    MAX_CONCURRENT_ARCHIVE_JOBS: intEnv(env.MAX_CONCURRENT_ARCHIVE_JOBS, 2, 1),
    // Cap on any server-side render that holds the whole content in
    // RAM and runs synchronous CPU work on it (blob view, commit/patch
    // diff, markdown). Above this, the UI shows a "too large to
    // preview" stub and links to the raw endpoint. Setting to 0
    // disables inline rendering entirely.
    MAX_RENDER_BYTES: intEnv(env.MAX_RENDER_BYTES, 10 * 1024 * 1024),
    // Cap on the streamed /raw download. 0 means no limit (current
    // behaviour) — useful on a trusted LAN where you actually want to
    // pull large blobs out of the browser. Public deployments should
    // pin this to something sane.
    MAX_RAW_DOWNLOAD_BYTES: intEnv(env.MAX_RAW_DOWNLOAD_BYTES, 0),
};

// Derived values that depend on other config fields
const baseUrl = new URL(config.BASE_URL);
config.PUBLIC_HTTPS = baseUrl.protocol === "https:";
config.PUBLIC_ORIGIN = baseUrl.origin;
config.COMMITTER_EMAIL =
    env.COMMITTER_EMAIL ?? `${config.OWNER_DISPLAY_NAME}@${baseUrl.hostname}`;

export default config;