import { asNumber, asString, parseJson, parseObject } from "@paperclipai/adapter-utils/server-utils";

function collectMessageText(message: unknown): string[] {
  if (typeof message === "string") {
    const trimmed = message.trim();
    return trimmed ? [trimmed] : [];
  }

  const record = parseObject(message);
  const direct = asString(record.text, "").trim();
  const lines: string[] = direct ? [direct] : [];
  const content = Array.isArray(record.content) ? record.content : [];

  for (const partRaw of content) {
    const part = parseObject(partRaw);
    const type = asString(part.type, "").trim();
    if (type === "output_text" || type === "text" || type === "content") {
      const text = asString(part.text, "").trim() || asString(part.content, "").trim();
      if (text) lines.push(text);
    }
  }

  return lines;
}

function readSessionId(event: Record<string, unknown>): string | null {
  return (
    asString(event.session_id, "").trim() ||
    asString(event.sessionId, "").trim() ||
    asString(event.sessionID, "").trim() ||
    asString(event.checkpoint_id, "").trim() ||
    asString(event.thread_id, "").trim() ||
    null
  );
}

function asErrorText(value: unknown): string {
  if (typeof value === "string") return value;
  const rec = parseObject(value);
  const message =
    asString(rec.message, "") ||
    asString(rec.error, "") ||
    asString(rec.code, "") ||
    asString(rec.detail, "");
  if (message) return message;
  try {
    return JSON.stringify(rec);
  } catch {
    return "";
  }
}

function accumulateUsage(
  target: { inputTokens: number; cachedInputTokens: number; outputTokens: number },
  usageRaw: unknown,
) {
  const usage = parseObject(usageRaw);
  const usageMetadata = parseObject(usage.usageMetadata);
  const source = Object.keys(usageMetadata).length > 0 ? usageMetadata : usage;

  target.inputTokens += asNumber(
    source.input_tokens,
    asNumber(source.inputTokens, asNumber(source.promptTokenCount, 0)),
  );
  target.cachedInputTokens += asNumber(
    source.cached_input_tokens,
    asNumber(source.cachedInputTokens, asNumber(source.cachedContentTokenCount, 0)),
  );
  target.outputTokens += asNumber(
    source.output_tokens,
    asNumber(source.outputTokens, asNumber(source.candidatesTokenCount, 0)),
  );
}

export function parseGeminiJsonl(stdout: string) {
  let sessionId: string | null = null;
  const messages: string[] = [];
  let errorMessage: string | null = null;
  let costUsd: number | null = null;
  const usage = {
    inputTokens: 0,
    cachedInputTokens: 0,
    outputTokens: 0,
  };

  for (const rawLine of stdout.split(/\r?\n/)) {
    const line = rawLine.trim();
    if (!line) continue;

    const event = parseJson(line);
    if (!event) continue;

    const foundSessionId = readSessionId(event);
    if (foundSessionId) sessionId = foundSessionId;

    const type = asString(event.type, "").trim();

    if (type === "assistant") {
      messages.push(...collectMessageText(event.message));
      continue;
    }

    if (type === "result") {
      accumulateUsage(usage, event.usage ?? event.usageMetadata);
      const resultText =
        asString(event.result, "").trim() ||
        asString(event.text, "").trim() ||
        asString(event.response, "").trim();
      if (resultText && messages.length === 0) messages.push(resultText);
      costUsd = asNumber(event.total_cost_usd, asNumber(event.cost_usd, asNumber(event.cost, costUsd ?? 0))) || costUsd;
      const isError = event.is_error === true || asString(event.subtype, "").toLowerCase() === "error";
      if (isError) {
        const text = asErrorText(event.error ?? event.message ?? event.result).trim();
        if (text) errorMessage = text;
      }
      continue;
    }

    if (type === "error") {
      const text = asErrorText(event.error ?? event.message ?? event.detail).trim();
      if (text) errorMessage = text;
      continue;
    }

    if (type === "system") {
      const subtype = asString(event.subtype, "").trim().toLowerCase();
      if (subtype === "error") {
        const text = asErrorText(event.error ?? event.message ?? event.detail).trim();
        if (text) errorMessage = text;
      }
      continue;
    }

    if (type === "text") {
      const part = parseObject(event.part);
      const text = asString(part.text, "").trim();
      if (text) messages.push(text);
      continue;
    }

    if (type === "step_finish" || event.usage || event.usageMetadata) {
      accumulateUsage(usage, event.usage ?? event.usageMetadata);
      costUsd = asNumber(event.total_cost_usd, asNumber(event.cost_usd, asNumber(event.cost, costUsd ?? 0))) || costUsd;
      continue;
    }
  }

  return {
    sessionId,
    summary: messages.join("\n\n").trim(),
    usage,
    costUsd,
    errorMessage,
  };
}

export function isGeminiUnknownSessionError(stdout: string, stderr: string): boolean {
  const haystack = `${stdout}\n${stderr}`
    .split(/\r?\n/)
    .map((line) => line.trim())
    .filter(Boolean)
    .join("\n");

  return /unknown\s+session|session\s+.*\s+not\s+found|resume\s+.*\s+not\s+found|checkpoint\s+.*\s+not\s+found|cannot\s+resume|failed\s+to\s+resume/i.test(
    haystack,
  );
}