// Shared helpers for Mistral probes. Key comes from process.env.MISTRAL_API_KEY (never logged).
import { mkdirSync, writeFileSync } from "node:fs";
import { deflateSync } from "node:zlib";
import OpenAI from "openai";
import { Mistral } from "@mistralai/mistralai";

export const BASE = "https://api.mistral.ai/v1";
export const KEY = process.env.MISTRAL_API_KEY ?? "";
if (!KEY) {
  console.error("MISTRAL_API_KEY missing (run: set -a; . ./.env; set +a)");
  process.exit(1);
}

export const OUT = new URL("./out/", import.meta.url).pathname;
mkdirSync(OUT, { recursive: true });

export const openai = new OpenAI({ apiKey: KEY, baseURL: BASE, timeout: 120_000, maxRetries: 0 });
export const mistral = new Mistral({ apiKey: KEY, retryConfig: { strategy: "none" } });

export const CHAT_MODELS = [
  "mistral-large-latest",
  "mistral-medium-latest",
  "mistral-small-latest",
  "ministral-8b-latest",
  "magistral-medium-latest",
  "magistral-small-latest",
  "codestral-latest",
];

export function save(name: string, data: unknown) {
  writeFileSync(`${OUT}${name}`, JSON.stringify(data, null, 2));
  console.log(`saved out/${name}`);
}

const HDR = /ratelimit|request-id|x-request|retry-after|content-type|server|date|cf-ray|x-kong|x-envoy|x-mistral|x-ms/i;

/** Raw request; returns status, selected headers, and parsed body (never echoes the key). */
export async function raw(path: string, init: RequestInit & { key?: string } = {}) {
  const { key, ...rest } = init;
  const res = await fetch(`${BASE}${path}`, {
    ...rest,
    headers: {
      "Content-Type": "application/json",
      Accept: "application/json",
      Authorization: `Bearer ${key ?? KEY}`,
      ...(rest.headers ?? {}),
    },
  });
  const text = await res.text();
  let body: unknown = text;
  try {
    body = JSON.parse(text);
  } catch {}
  const headers: Record<string, string> = {};
  res.headers.forEach((v, k) => {
    if (HDR.test(k)) headers[k] = v;
  });
  return { status: res.status, headers, body };
}

export function post(path: string, payload: unknown, key?: string) {
  return raw(path, { method: "POST", body: JSON.stringify(payload), key });
}

/** Raw SSE POST; returns list of parsed events (data lines). */
export async function rawSSE(path: string, payload: unknown, key?: string) {
  const res = await fetch(`${BASE}${path}`, {
    method: "POST",
    headers: { "Content-Type": "application/json", Accept: "text/event-stream", Authorization: `Bearer ${key ?? KEY}` },
    body: JSON.stringify(payload),
  });
  const headers: Record<string, string> = {};
  res.headers.forEach((v, k) => {
    if (HDR.test(k)) headers[k] = v;
  });
  if (!res.ok || !res.body) {
    const text = await res.text();
    let body: unknown = text;
    try {
      body = JSON.parse(text);
    } catch {}
    return { status: res.status, headers, error: body, events: [] as any[] };
  }
  const reader = res.body.getReader();
  const dec = new TextDecoder();
  let buf = "";
  const events: { event?: string; data: any; raw?: string }[] = [];
  for (;;) {
    const { value, done } = await reader.read();
    if (done) break;
    buf += dec.decode(value, { stream: true });
    let idx;
    while ((idx = buf.indexOf("\n\n")) >= 0) {
      const block = buf.slice(0, idx);
      buf = buf.slice(idx + 2);
      let ev: string | undefined;
      const datas: string[] = [];
      for (const line of block.split("\n")) {
        if (line.startsWith("event:")) ev = line.slice(6).trim();
        else if (line.startsWith("data:")) datas.push(line.slice(5).trim());
      }
      if (!datas.length) continue;
      const d = datas.join("\n");
      if (d === "[DONE]") {
        events.push({ event: ev, data: "[DONE]" });
        continue;
      }
      try {
        events.push({ event: ev, data: JSON.parse(d) });
      } catch {
        events.push({ event: ev, data: null, raw: d });
      }
    }
  }
  return { status: res.status, headers, events };
}

export function short(s: unknown, n = 300) {
  const t = typeof s === "string" ? s : JSON.stringify(s) ?? String(s);
  return t.length > n ? t.slice(0, n) + "…" : t;
}

/** Minimal valid PNG (RGB, solid colour with a diagonal), size x size, base64 data URL. */
export function pngDataUrl(size = 32): string {
  const crcTable = new Int32Array(256);
  for (let n = 0; n < 256; n++) {
    let c = n;
    for (let k = 0; k < 8; k++) c = c & 1 ? 0xedb88320 ^ (c >>> 1) : c >>> 1;
    crcTable[n] = c;
  }
  const crc32 = (buf: Buffer) => {
    let c = -1;
    for (const b of buf) c = crcTable[(c ^ b) & 0xff] ^ (c >>> 8);
    return (c ^ -1) >>> 0;
  };
  const chunk = (type: string, data: Buffer) => {
    const len = Buffer.alloc(4);
    len.writeUInt32BE(data.length);
    const td = Buffer.concat([Buffer.from(type, "ascii"), data]);
    const crc = Buffer.alloc(4);
    crc.writeUInt32BE(crc32(td));
    return Buffer.concat([len, td, crc]);
  };
  const ihdr = Buffer.alloc(13);
  ihdr.writeUInt32BE(size, 0);
  ihdr.writeUInt32BE(size, 4);
  ihdr[8] = 8; // bit depth
  ihdr[9] = 2; // RGB
  const rows: Buffer[] = [];
  for (let y = 0; y < size; y++) {
    const row = Buffer.alloc(1 + size * 3);
    for (let x = 0; x < size; x++) {
      const onDiag = Math.abs(x - y) < 2;
      row[1 + x * 3] = onDiag ? 255 : 30; // R
      row[2 + x * 3] = onDiag ? 255 : 60; // G
      row[3 + x * 3] = onDiag ? 255 : 200; // B
    }
    rows.push(row);
  }
  const idat = deflateSync(Buffer.concat(rows));
  const png = Buffer.concat([
    Buffer.from([0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a]),
    chunk("IHDR", ihdr),
    chunk("IDAT", idat),
    chunk("IEND", Buffer.alloc(0)),
  ]);
  return `data:image/png;base64,${png.toString("base64")}`;
}