import type { SessionEntry } from "./types";

export async function sendChat(threadId: string | null, message: string): Promise<{ threadId: string; response: string }> {
  const r = await fetch("/code/api/chat", {
    method: "POST",
    headers: { "Content-Type": "application/json" },
    body: JSON.stringify({ threadId, message }),
    signal: AbortSignal.timeout(300000),
  });
  if (!r.ok) {
    const err = await r.json().catch(() => ({ error: "HTTP " + r.status }));
    throw new Error(err.error);
  }
  return r.json();
}

export async function sendChatStream(
  threadId: string | null,
  message: string,
  onText: (chunk: string) => void,
  opts?: { title?: string },
): Promise<{ threadId: string }> {
  const r = await fetch("/code/api/chat-stream", {
    method: "POST",
    headers: { "Content-Type": "application/json" },
    body: JSON.stringify({ threadId, message, title: opts?.title }),
  });
  if (!r.ok) {
    const err = await r.json().catch(() => ({ error: "HTTP " + r.status }));
    throw new Error(err.error);
  }

  const reader = r.body!.getReader();
  const decoder = new TextDecoder();
  let buffer = "";
  let returnedTid = threadId || "";
  let eventType = "";

  while (true) {
    const { done, value } = await reader.read();
    if (done) break;
    buffer += decoder.decode(value, { stream: true });

    const lines = buffer.split("\n");
    buffer = lines.pop()!;

    for (const line of lines) {
      if (line.startsWith("event: ")) {
        eventType = line.slice(7);
      } else if (line.startsWith("data: ")) {
        const data = JSON.parse(line.slice(6));
        if (eventType === "thread") returnedTid = data.threadId;
        else if (eventType === "text") onText(data.text);
        else if (eventType === "error") throw new Error(data.error);
        eventType = "";
      }
    }
  }

  return { threadId: returnedTid };
}

export async function fetchSessionLog(sessionFile: string, n = 30): Promise<SessionEntry[]> {
  const r = await fetch(`/code/api/session-tails?file=${encodeURIComponent(sessionFile)}&n=${n}&t=${Date.now()}`);
  if (!r.ok) throw new Error("HTTP " + r.status);
  return r.json();
}

export async function attachThread(threadId: string, linearIssue: string): Promise<void> {
  await fetch("/code/api/attach-thread", {
    method: "POST",
    headers: { "Content-Type": "application/json" },
    body: JSON.stringify({ threadId, linearIssue }),
  });
}

export async function deleteThread(channel: string, threadId: string): Promise<void> {
  await fetch("/code/api/delete-thread", {
    method: "POST",
    headers: { "Content-Type": "application/json" },
    body: JSON.stringify({ channel, threadId }),
  });
}

export async function updateThreadStatus(channel: string, threadId: string, status: string): Promise<void> {
  await fetch("/code/api/update-thread", {
    method: "POST",
    headers: { "Content-Type": "application/json" },
    body: JSON.stringify({ channel, threadId, status }),
  });
}