import { Hono } from "hono";
import { serveStatic } from "@hono/node-server/serve-static";
import { serve } from "@hono/node-server";
import Anthropic from "@anthropic-ai/sdk";
import { readFileSync } from "node:fs";
import { join } from "node:path";
import { homedir } from "node:os";

const app = new Hono();

// Use Claude Code subscription credentials
// Priority: ANTHROPIC_API_KEY env var > ~/.claude/.credentials.json
function getApiKey(): string {
  if (process.env.ANTHROPIC_API_KEY) return process.env.ANTHROPIC_API_KEY;
  try {
    const credsPath = join(homedir(), ".claude", ".credentials.json");
    const creds = JSON.parse(readFileSync(credsPath, "utf-8"));
    const token = creds?.claudeAiOauth?.accessToken;
    if (token) return token;
  } catch {}
  throw new Error("No Anthropic credentials found. Install Claude Code and authenticate, or set ANTHROPIC_API_KEY.");
}

let apiKey = getApiKey();
let client = new Anthropic({ apiKey });

// Re-read credentials every 30 min in case Claude Code refreshed the token
setInterval(() => {
  try {
    const fresh = getApiKey();
    if (fresh !== apiKey) {
      apiKey = fresh;
      client = new Anthropic({ apiKey });
      console.log("Refreshed Anthropic credentials from Claude Code");
    }
  } catch {}
}, 30 * 60_000);

const SYSTEM_PROMPT = `You are a meditation guide. Generate one short, calming guidance message for a meditation session.

Rules:
- One sentence only, 8-20 words
- Gentle, present-tense, second person ("you")
- No questions, no exclamation marks
- Match the phase: "start" = settling in, "middle" = sustained awareness, "end" = returning
- Never repeat common meditation clichés verbatim
- Vary your language — draw from mindfulness, somatic awareness, nature imagery, gratitude, breath, stillness`;

const lastCall = new Map<string, number>();

app.post("/api/guidance", async (c) => {
  const body = await c.req.json<{
    phase: string;
    progress: number;
    duration: number;
    streak: number;
    sessionCount: number;
    sessionId: string;
  }>();

  const now = Date.now();
  const last = lastCall.get(body.sessionId) || 0;
  if (now - last < 20_000) {
    return c.json({ error: "rate limited" }, 429);
  }
  lastCall.set(body.sessionId, now);

  if (lastCall.size > 1000) {
    const cutoff = now - 3_600_000;
    for (const [k, v] of lastCall) {
      if (v < cutoff) lastCall.delete(k);
    }
  }

  const contextParts = [`Phase: ${body.phase}`, `Progress: ${Math.round(body.progress * 100)}%`];
  if (body.duration) contextParts.push(`Session length: ${body.duration} minutes`);
  if (body.streak > 1) contextParts.push(`User is on a ${body.streak}-day streak`);
  if (body.sessionCount > 1) contextParts.push(`This is their session #${body.sessionCount}`);

  try {
    const msg = await client.messages.create({
      model: "claude-haiku-4-5-20251001",
      max_tokens: 60,
      system: SYSTEM_PROMPT,
      messages: [{ role: "user", content: contextParts.join(". ") + "." }],
    });

    const text =
      msg.content[0].type === "text" ? msg.content[0].text.trim().replace(/^["']|["']$/g, "") : "";

    return c.json({ text });
  } catch (e) {
    console.error("Guidance API error:", e);
    return c.json({ error: "generation failed" }, 500);
  }
});

app.use("/*", serveStatic({ root: "./app" }));

const port = parseInt(process.env.PORT || "3000");
console.log(`Palace Meditate running on :${port}`);
serve({ fetch: app.fetch, port });