//
// Instances that answer SSH on a different hostname than their web UI.
//
// The remote host is what discovery matches against, so `git@ssh.gitea.test:…`
// on an instance at `https://gitea.test` resolves to nothing until an alias
// exists — either configured by hand, or detected once from the ssh_url the
// repository advertises and then reused from preferences ever after.
//

const { EXTENSION_ROOT } = require("./nova-stub.js");
require("./fake-gitea.js");
const { Checker } = require("./assert.js");

const path = require("node:path");
const fs = require("node:fs");
const os = require("node:os");
const { execFileSync } = require("node:child_process");

const script = (...parts) => path.join(EXTENSION_ROOT, "Scripts", ...parts);
const t = new Checker();

const INSTANCE = "https://gitea.test";
const SSH_HOST = "ssh.gitea.test";

const { InstanceRouter } = require(script("gitea", "router.js"));
const credentials = require(script("gitea", "credentials.js"));
const discovery = require(script("gitea", "discovery.js"));
const config = require(script("util", "config.js"));

// -- fixtures --------------------------------------------------------------

const temporary = [];

/** A throwaway workspace holding one git repository with the given remote. */
function workspaceWith(name, remoteUrl) {
    const workspace = fs.mkdtempSync(path.join(os.tmpdir(), "gitea-nova-alias-"));
    temporary.push(workspace);

    const repo = path.join(workspace, name);
    fs.mkdirSync(repo, { recursive: true });
    fs.writeFileSync(path.join(repo, "README.md"), `# ${name}\n`);

    const git = (...args) => execFileSync("git", args, { cwd: repo, encoding: "utf-8" });
    git("init", "-q", "-b", "main");
    git("config", "user.email", "test@example.com");
    git("config", "user.name", "Test");
    git("remote", "add", "origin", remoteUrl);
    git("add", "-A");
    git("commit", "-qm", "initial");

    return workspace;
}

function cleanup() {
    for (const dir of temporary) fs.rmSync(dir, { recursive: true, force: true });
}

/** A fresh router with the alias preference set to `entries`. */
function routerWith(entries) {
    nova.config.set("gitea.hostAliases", entries);
    return new InstanceRouter();
}

nova.workspace.path = workspaceWith("widget", `git@${SSH_HOST}:acme/widget.git`);
nova.config.set("gitea.baseUrl", INSTANCE);

(async () => {
    t.section("alias parsing");
    for (const [label, entry] of [
        ["equals separator", `${SSH_HOST} = ${INSTANCE}`],
        ["arrow separator", `${SSH_HOST} -> ${INSTANCE}`],
        ["fat arrow separator", `${SSH_HOST}=>${INSTANCE}`],
        ["bare host as the target", `${SSH_HOST} = gitea.test`],
        ["untidy whitespace", `   ${SSH_HOST}   =    ${INSTANCE}   `],
        ["ports ignored on both sides", `${SSH_HOST}:2222 = ${INSTANCE}`],
        ["case-insensitive", `${SSH_HOST.toUpperCase()} = ${INSTANCE}`],
    ]) {
        t.equals(label, routerWith([entry]).baseUrlForHost(SSH_HOST), INSTANCE);
    }
    t.equals(
        "a direct host match still wins",
        routerWith([`${SSH_HOST} = ${INSTANCE}`]).baseUrlForHost("gitea.test"),
        INSTANCE,
    );

    t.section("alias entries that should be ignored");
    for (const [label, entry] of [
        ["blank", "   "],
        ["comment", `# ${SSH_HOST} = ${INSTANCE}`],
        ["no separator", `${SSH_HOST} ${INSTANCE}`],
        ["too many separators", `${SSH_HOST} = ${INSTANCE} = extra`],
        ["self-referential", `${SSH_HOST} = ${SSH_HOST}`],
    ]) {
        t.equals(label, routerWith([entry]).baseUrlForHost(SSH_HOST), null);
    }
    t.equals(
        "an unrelated host stays unmatched",
        routerWith([`${SSH_HOST} = ${INSTANCE}`]).baseUrlForHost("github.com"),
        null,
    );

    t.section("unmatched: no alias and nothing to ask");
    // Without a token there is no instance to interrogate, so this is the pure
    // host-matching path and it must fail visibly rather than silently.
    nova.config.set("gitea.hostAliases", []);
    credentials.removeToken(INSTANCE);

    const bare = new InstanceRouter();
    const unmatched = await discovery.discover(bare);
    t.equals("no repository resolves", unmatched.repos.length, 0);
    t.equals("the unmatched host is reported", unmatched.unmatched.map((u) => u.host), [SSH_HOST]);
    t.equals(
        "the report carries the remote for context",
        unmatched.unmatched[0]?.remoteUrl,
        `git@${SSH_HOST}:acme/widget.git`,
    );
    t.equals("and nothing was persisted", nova.config.get("gitea.hostAliases", "array"), []);

    t.section("matched: alias configured by hand");
    const configured = routerWith([`${SSH_HOST} = ${INSTANCE}`]);
    const viaConfig = await discovery.discover(configured);
    t.equals("the repository resolves", viaConfig.repos.length, 1);
    t.equals("routed to the web instance", viaConfig.repos[0]?.baseUrl, INSTANCE);
    t.equals("owner and name come from the remote", viaConfig.repos[0]?.fullName, "acme/widget");
    t.equals("nothing left unmatched", viaConfig.unmatched.length, 0);

    t.section("matched: alias detected from the API");
    // No alias configured, but a token is available. The instance is asked for
    // the repository and identifies itself through the ssh_url it advertises.
    nova.config.set("gitea.hostAliases", []);
    credentials.setToken(INSTANCE, "tok_test");

    const detecting = new InstanceRouter();
    const detected = await discovery.discover(detecting);
    t.equals("the repository resolves with no configuration", detected.repos.length, 1);
    t.equals("routed to the web instance", detected.repos[0]?.baseUrl, INSTANCE);
    t.equals("nothing left unmatched", detected.unmatched.length, 0);
    t.check("the host was probed", detecting._probedHosts.has(SSH_HOST));
    t.check(
        "the alias is live on the router",
        detecting.aliases.get(SSH_HOST) === "gitea.test",
        detecting.aliases.get(SSH_HOST),
    );
    t.check(
        "and was written to preferences",
        (nova.config.get("gitea.hostAliases", "array") || []).includes(`${SSH_HOST} = ${INSTANCE}`),
        JSON.stringify(nova.config.get("gitea.hostAliases", "array")),
    );

    t.section("a later repository on the same host");
    // What the stored alias buys: a different repository, in a different
    // workspace, resolves straight away without another round trip.
    nova.workspace.path = workspaceWith("gadget", `git@${SSH_HOST}:acme/gadget.git`);

    const returning = new InstanceRouter();
    const later = await discovery.discover(returning);
    t.equals("the new repository resolves", later.repos.length, 1);
    t.equals("identified correctly", later.repos[0]?.fullName, "acme/gadget");
    t.equals("routed to the web instance", later.repos[0]?.baseUrl, INSTANCE);
    t.equals("nothing left unmatched", later.unmatched.length, 0);
    t.equals("and no probe was needed", returning._probedHosts.size, 0);

    t.section("detection is not repeated");
    // A host belonging to no instance must not be probed on every refresh.
    nova.config.set("gitea.hostAliases", []);
    const probing = new InstanceRouter();
    t.equals("first probe finds nothing", await probing.detectHostAlias("elsewhere.test", "a", "b"), null);
    t.check("the host is remembered as probed", probing._probedHosts.has("elsewhere.test"));
    t.equals("a second probe short-circuits", await probing.detectHostAlias("elsewhere.test", "a", "b"), null);
    probing.invalidate();
    t.check("an explicit refresh clears the record", !probing._probedHosts.has("elsewhere.test"));

    t.section("persisting an alias");
    nova.config.set("gitea.hostAliases", []);
    t.equals("a new alias is written", config.addHostAlias(SSH_HOST, INSTANCE), true);
    t.equals("writing the same alias again is a no-op", config.addHostAlias(SSH_HOST, INSTANCE), false);
    t.equals(
        "re-pointing a host replaces rather than duplicates",
        config.addHostAlias(SSH_HOST, "https://other.test"),
        true,
    );
    t.equals("one entry per host", (nova.config.get("gitea.hostAliases", "array") || []).length, 1);

    t.section("workspace aliases add to global ones");
    nova.config.set("gitea.hostAliases", [`${SSH_HOST} = ${INSTANCE}`]);
    nova.workspace.config.set("gitea.hostAliases", [`other.test = ${INSTANCE}`]);
    const merged = new InstanceRouter();
    t.equals("global entry applies", merged.baseUrlForHost(SSH_HOST), INSTANCE);
    t.equals("workspace entry applies", merged.baseUrlForHost("other.test"), INSTANCE);
    nova.workspace.config.remove("gitea.hostAliases");

    cleanup();
    t.finish("HOST ALIAS CHECKS");
})().catch((error) => {
    console.error("HARNESS ERROR", error);
    cleanup();
    process.exit(2);
});