import fs from "node:fs";

export type HarEntry = {
  request: { url: string; method: string };
  response: {
    status: number;
    content?: { mimeType?: string; text?: string };
  };
};

export type HarFile = {
  log?: { entries?: HarEntry[] };
};

export function readHarFile(harPath: string): HarFile {
  const raw = fs.readFileSync(harPath, "utf8");
  return JSON.parse(raw) as HarFile;
}

export function listHarEntries(har: HarFile): HarEntry[] {
  return har.log?.entries ?? [];
}

export function parseHarResponseJson(entry: HarEntry): unknown | null {
  const text = entry.response.content?.text;
  if (!text?.trim()) {
    return null;
  }
  try {
    return JSON.parse(text) as unknown;
  } catch {
    return null;
  }
}

const QUOTE_URL_PATTERN =
  /axel\/quote|api\.mothership\.com|plugins\.mothership\.com|services\.mothership\.com/i;
const QUOTE_URL_HINT = /quote|rate|pricing|graphql/i;

export function isQuoteHarEntry(entry: HarEntry): boolean {
  if (entry.response.status < 200 || entry.response.status >= 300) {
    return false;
  }
  const mime = entry.response.content?.mimeType ?? "";
  if (!/json/i.test(mime) && !entry.response.content?.text?.trim().startsWith("{")) {
    return false;
  }
  const url = entry.request.url.toLowerCase();
  if (QUOTE_URL_PATTERN.test(url)) {
    return true;
  }
  return QUOTE_URL_HINT.test(url) && /mothership/i.test(url);
}

export function scoreQuoteBody(body: unknown): number {
  if (body == null || typeof body !== "object") {
    return 0;
  }
  let score = 0;
  const text = JSON.stringify(body).toLowerCase();
  if (text.includes("rates")) {
    score += 3;
  }
  if (text.includes("standard")) {
    score += 2;
  }
  if (text.includes("guaranteed")) {
    score += 2;
  }
  if (text.includes("freight") || text.includes("price")) {
    score += 1;
  }
  if (text.includes("place_id") || text.includes("placeid")) {
    score += 1;
  }
  return score;
}

export function pickBestQuoteEntry(entries: HarEntry[]): {
  entry: HarEntry;
  body: unknown;
} | null {
  let best: { entry: HarEntry; body: unknown; score: number } | null = null;

  for (const entry of entries) {
    if (!isQuoteHarEntry(entry)) {
      continue;
    }
    const body = parseHarResponseJson(entry);
    if (body == null) {
      continue;
    }
    const score = scoreQuoteBody(body);
    if (score <= 0) {
      continue;
    }
    if (!best || score > best.score) {
      best = { entry, body, score };
    }
  }

  return best ? { entry: best.entry, body: best.body } : null;
}