/**
 * Readiness detection: port probing, pattern matching, wait-for-ready.
 */
import { createConnection } from "node:net";
import { addEvent, pushAlert } from "./process-manager.js";
import { DEFAULT_READY_TIMEOUT, PORT_PROBE_TIMEOUT, READY_POLL_INTERVAL, } from "./types.js";
// ── Readiness Transition ───────────────────────────────────────────────────
export function transitionToReady(bg, detail) {
    bg.status = "ready";
    bg.wasReady = true;
    addEvent(bg, { type: "ready", detail });
}
// ── Port Probing ───────────────────────────────────────────────────────────
export function probePort(port, host = "127.0.0.1") {
    return new Promise((resolve) => {
        const socket = createConnection({ port, host, timeout: PORT_PROBE_TIMEOUT }, () => {
            socket.destroy();
            resolve(true);
        });
        socket.on("error", () => {
            socket.destroy();
            resolve(false);
        });
        socket.on("timeout", () => {
            socket.destroy();
            resolve(false);
        });
    });
}
// ── Port Probing Loop ──────────────────────────────────────────────────────
export function startPortProbing(bg, port, customTimeout) {
    const timeout = customTimeout || DEFAULT_READY_TIMEOUT;
    const interval = setInterval(async () => {
        if (!bg.alive) {
            clearInterval(interval);
            const stderrLines = bg.output
                .filter((l) => l.stream === "stderr")
                .slice(-10)
                .map((l) => l.line);
            const detail = `Process exited (code ${bg.exitCode}) before port ${port} opened${stderrLines.length > 0 ? ` — ${stderrLines.join("; ").slice(0, 200)}` : ""}`;
            addEvent(bg, {
                type: "port_timeout",
                detail,
                data: { port, exitCode: bg.exitCode },
            });
            return;
        }
        if (bg.status !== "starting") {
            clearInterval(interval);
            return;
        }
        const open = await probePort(port);
        if (open) {
            clearInterval(interval);
            if (!bg.ports.includes(port))
                bg.ports.push(port);
            transitionToReady(bg, `Port ${port} is open`);
            addEvent(bg, {
                type: "port_open",
                detail: `Port ${port} is open`,
                data: { port },
            });
        }
    }, READY_POLL_INTERVAL);
    // Stop probing after timeout — transition to error state so the process
    // doesn't stay in "starting" forever (fixes #428)
    setTimeout(() => {
        clearInterval(interval);
        if (bg.alive && bg.status === "starting") {
            const stderrLines = bg.output
                .filter((l) => l.stream === "stderr")
                .slice(-10)
                .map((l) => l.line);
            const detail = `Port ${port} not open after ${timeout}ms${stderrLines.length > 0 ? ` — ${stderrLines.join("; ").slice(0, 200)}` : ""}`;
            bg.status = "error";
            addEvent(bg, { type: "port_timeout", detail, data: { port, timeout } });
            pushAlert(bg, `Port ${port} readiness timeout after ${timeout / 1000}s`);
        }
    }, timeout);
}
// ── Wait for Ready ─────────────────────────────────────────────────────────
export async function waitForReady(bg, timeout, signal) {
    const start = Date.now();
    while (Date.now() - start < timeout) {
        if (signal?.aborted) {
            return { ready: false, detail: "Cancelled" };
        }
        if (!bg.alive) {
            const stderrLines = bg.output
                .filter((l) => l.stream === "stderr")
                .slice(-5)
                .map((l) => l.line);
            const stderrContext = stderrLines.length > 0
                ? `\nstderr:\n${stderrLines.join("\n").slice(0, 500)}`
                : "";
            return {
                ready: false,
                detail: `Process exited before becoming ready (code ${bg.exitCode})${bg.recentErrors.length > 0 ? ` — ${bg.recentErrors.slice(-1)[0]}` : ""}${stderrContext}`,
            };
        }
        if (bg.status === "error") {
            const stderrLines = bg.output
                .filter((l) => l.stream === "stderr")
                .slice(-5)
                .map((l) => l.line);
            const stderrContext = stderrLines.length > 0
                ? `\nstderr:\n${stderrLines.join("\n").slice(0, 500)}`
                : "";
            return {
                ready: false,
                detail: `Process entered error state${bg.readyPort ? ` (port ${bg.readyPort} never opened)` : ""}${stderrContext}`,
            };
        }
        if (bg.status === "ready") {
            return {
                ready: true,
                detail: bg.events.find((e) => e.type === "ready")?.detail ||
                    "Process is ready",
            };
        }
        await new Promise((r) => setTimeout(r, READY_POLL_INTERVAL));
    }
    // Timeout — try port probe as last resort
    if (bg.readyPort) {
        const open = await probePort(bg.readyPort);
        if (open) {
            transitionToReady(bg, `Port ${bg.readyPort} is open (detected at timeout)`);
            return { ready: true, detail: `Port ${bg.readyPort} is open` };
        }
    }
    const stderrLines = bg.output
        .filter((l) => l.stream === "stderr")
        .slice(-5)
        .map((l) => l.line);
    const stderrContext = stderrLines.length > 0
        ? `\nstderr:\n${stderrLines.join("\n").slice(0, 500)}`
        : "";
    return {
        ready: false,
        detail: `Timed out after ${timeout}ms waiting for ready signal${stderrContext}`,
    };
}