import express from "express";
import dotenv from "dotenv";
import cors from "cors";
import fs from "fs";
import path from "path";
import { reflectWithCortex, ingestToCortex } from "./lib/cortex.js";

dotenv.config();

const sessionsDir = path.join(process.cwd(), "sessions");
if (!fs.existsSync(sessionsDir)) fs.mkdirSync(sessionsDir);

const app = express();
app.use(cors());
app.use(express.json());

// Cache and normalize env flags/values once
const {
  NEOMEM_API,
  MEM0_API_KEY,
  OPENAI_API_KEY,
  OLLAMA_URL,
  PERSONA_URL,
  CORTEX_ENABLED,
  PORT: PORT_ENV,
  DEBUG_PROMPT,
} = process.env;

const PORT = Number(PORT_ENV) || 7078;
const cortexEnabled = String(CORTEX_ENABLED).toLowerCase() === "true";
const debugPrompt = String(DEBUG_PROMPT).toLowerCase() === "true";

// Basic env validation warnings (non-fatal)
if (!NEOMEM_API || !MEM0_API_KEY) {
  console.warn("⚠️ NeoMem configuration missing: NEOMEM_API or MEM0_API_KEY not set.");
}

/* ------------------------------
   Helpers for NeoMem REST API
--------------------------------*/
// Small helper for fetch with timeout + JSON + error detail
async function fetchJSON(url, options = {}, timeoutMs = 30000) {
  const controller = new AbortController();
  const t = setTimeout(() => controller.abort(), timeoutMs);
  try {
    const resp = await fetch(url, { ...options, signal: controller.signal });
    const text = await resp.text();
    const parsed = text ? JSON.parse(text) : null;
    if (!resp.ok) {
      const msg = parsed?.error || parsed?.message || text || resp.statusText;
      throw new Error(`${resp.status} ${msg}`);
    }
    return parsed;
  } finally {
    clearTimeout(t);
  }
}

async function memAdd(content, userId, sessionId, cortexData) {
  const url = `${NEOMEM_API}/memories`;
  const payload = {
    messages: [{ role: "user", content }],
    user_id: userId,
    // run_id: sessionId,
    metadata: { source: "relay", cortex: cortexData },
  };
  return fetchJSON(url, {
    method: "POST",
    headers: {
      "Content-Type": "application/json",
      Authorization: `Bearer ${MEM0_API_KEY}`,
    },
    body: JSON.stringify(payload),
  });
}

async function memSearch(query, userId, sessionId) {
  const url = `${NEOMEM_API}/search`;
  const payload = { query, user_id: userId };
  return fetchJSON(url, {
    method: "POST",
    headers: {
      "Content-Type": "application/json",
      Authorization: `Bearer ${MEM0_API_KEY}`,
    },
    body: JSON.stringify(payload),
  });
}

/* ------------------------------
   Utility to time spans
--------------------------------*/
async function span(name, fn) {
  const start = Date.now();
  try {
    return await fn();
  } finally {
    console.log(`${name} took ${Date.now() - start}ms`);
  }
}

/* ------------------------------
   Healthcheck
--------------------------------*/
app.get("/_health", (req, res) => {
  res.json({ ok: true, time: new Date().toISOString() });
});

/* ------------------------------
   Sessions
--------------------------------*/
// List all saved sessions
app.get("/sessions", (_, res) => {
  const list = fs.readdirSync(sessionsDir)
    .filter(f => f.endsWith(".json"))
    .map(f => f.replace(".json", ""));
  res.json(list);
});

// Load a single session
app.get("/sessions/:id", (req, res) => {
  const file = path.join(sessionsDir, `${req.params.id}.json`);
  if (!fs.existsSync(file)) return res.json([]);
  res.json(JSON.parse(fs.readFileSync(file, "utf8")));
});

// Save or update a session
app.post("/sessions/:id", (req, res) => {
  const file = path.join(sessionsDir, `${req.params.id}.json`);
  fs.writeFileSync(file, JSON.stringify(req.body, null, 2));
  res.json({ ok: true });
});

/* ------------------------------
   Chat completion endpoint
--------------------------------*/
app.post("/v1/chat/completions", async (req, res) => {
  try {
    const { model, messages, sessionId: clientSessionId } = req.body || {};
    if (!Array.isArray(messages) || !messages.length) {
      return res.status(400).json({ error: "invalid_messages" });
    }
    if (!model || typeof model !== "string") {
      return res.status(400).json({ error: "invalid_model" });
    }

    const sessionId = clientSessionId || "default";
    const userId = "brian"; // fixed for now

    console.log(`🛰️ Incoming request. Session: ${sessionId}`);

    // Find last user message efficiently
    const lastUserMsg = [...messages].reverse().find(m => m.role === "user")?.content;
    if (!lastUserMsg) {
      return res.status(400).json({ error: "no_user_message" });
    }

	// 1. Cortex Reflection (new pipeline)
	/*let reflection = {};
	try {
	  console.log("🧠 Reflecting with Cortex...");
	  const memoriesPreview = []; // we'll fill this in later with memSearch
	  reflection = await reflectWithCortex(lastUserMsg, memoriesPreview);
	  console.log("🔍 Reflection:", reflection);
	} catch (err) {
	  console.warn("⚠️ Cortex reflect failed:", err.message);
	  reflection = { error: err.message };
	}*/

    // 2. Search memories
   /* let memorySnippets = [];
    await span("mem.search", async () => {
      if (NEOMEM_API && MEM0_API_KEY) {
        try {
          const { results } = await memSearch(lastUserMsg, userId, sessionId);
          if (results?.length) {
            console.log(`📚 Mem0 hits: ${results.length}`);
            results.forEach((r, i) =>
              console.log(`   ${i + 1}) ${r.memory} (score ${Number(r.score).toFixed(3)})`)
            );
            memorySnippets = results.map((r, i) => `${i + 1}) ${r.memory}`);
          } else {
            console.log("😴 No memories found");
          }
        } catch (e) {
          console.warn("⚠️ mem.search failed:", e.message);
        }
      }
    });*/

    // 3. Fetch persona
/*     let personaText = "Persona: Lyra 🤖 friendly, concise, poker-savvy.";
    await span("persona.fetch", async () => {
      try {
        if (PERSONA_URL) {
          const data = await fetchJSON(PERSONA_URL);
          if (data?.persona) {
            const name = data.persona.name ?? "Lyra";
            const style = data.persona.style ?? "friendly, concise";
            const protocols = Array.isArray(data.persona.protocols) ? data.persona.protocols.join(", ") : "";
            personaText = `Persona: ${name} 🤖 ${style}. Protocols: ${protocols}`.trim();
          }
        }
      } catch (err) {
        console.error("💥 persona.fetch failed", err);
      }
    }); */
	
	// 1. Ask Cortex to build the final prompt
	let cortexPrompt = "";
	try {
	  console.log("🧠 Requesting prompt from Cortex...");
	  const response = await fetch(`${process.env.CORTEX_API_URL || "http://10.0.0.41:7081"}/reason`, {
		method: "POST",
		headers: { "Content-Type": "application/json" },
		body: JSON.stringify({
		  prompt: lastUserMsg,
		  session_id: sessionId,
		  user_id: userId
		})
	  });
	  const data = await response.json();
	  cortexPrompt = data.full_prompt || data.prompt || "";
	  console.log("🧩 Cortex returned prompt");
	} catch (err) {
	  console.warn("⚠️ Cortex prompt build failed:", err.message);
	}


	// 4. Build final messages
	const injectedMessages = [
	  { role: "system", content: cortexPrompt || "You are Lyra." },
	  ...messages,
	];

    if (debugPrompt) {
      console.log("\n==== Injected Prompt ====");
      console.log(JSON.stringify(injectedMessages, null, 2));
      console.log("=========================\n");
    }

	// 5. Call LLM (OpenAI or Ollama)
	const isOllama = model.startsWith("ollama:");
	const llmUrl = isOllama
	  ? `${OLLAMA_URL}/api/chat`
	  : "https://api.openai.com/v1/chat/completions";

	const llmHeaders = isOllama
	  ? { "Content-Type": "application/json" }
	  : {
		  "Content-Type": "application/json",
		  Authorization: `Bearer ${OPENAI_API_KEY}`,
		};

	const llmBody = {
	  model: isOllama ? model.replace("ollama:", "") : model,
	  messages: injectedMessages,   // <-- make sure injectedMessages is defined above this section
	  stream: false,
	};

	const data = await fetchJSON(llmUrl, {
	  method: "POST",
	  headers: llmHeaders,
	  body: JSON.stringify(llmBody),
	});

	// define once for everything below
	const assistantReply = isOllama
	  ? data?.message?.content
	  : data?.choices?.[0]?.message?.content || data?.choices?.[0]?.text || "";

	// 🧠 Send exchange back to Cortex for ingest
	try {
	  await ingestToCortex(lastUserMsg, assistantReply || "", {}, sessionId);
	  console.log("📤 Sent exchange back to Cortex ingest");
	} catch (err) {
	  console.warn("⚠️ Cortex ingest failed:", err.message);
	}

	// 💾 Save exchange to session log
	try {
	  const logFile = path.join(sessionsDir, `${sessionId}.jsonl`);
	  const entry = JSON.stringify({
		ts: new Date().toISOString(),
		turn: [
		  { role: "user", content: lastUserMsg },
		  { role: "assistant", content: assistantReply || "" }
		]
	  }) + "\n";
	  fs.appendFileSync(logFile, entry, "utf8");
	  console.log(`🧠 Logged session exchange → ${logFile}`);
	} catch (e) {
	  console.warn("⚠️ Session log write failed:", e.message);
	}

	// 🔄 Forward user↔assistant exchange to Intake summarizer
	if (process.env.INTAKE_API_URL) {
	  try {
		const intakePayload = {
		  session_id: sessionId,
		  turns: [
			{ role: "user", content: lastUserMsg },
			{ role: "assistant", content: assistantReply || "" }
		  ]
		};

		await fetch(process.env.INTAKE_API_URL, {
		  method: "POST",
		  headers: { "Content-Type": "application/json" },
		  body: JSON.stringify(intakePayload),
		});

		console.log("📨 Sent exchange to Intake summarizer");
	  } catch (err) {
		console.warn("⚠️ Intake post failed:", err.message);
	  }
	}



    if (isOllama) {
      res.json({
        id: "ollama-" + Date.now(),
        object: "chat.completion",
        created: Math.floor(Date.now() / 1000),
        model,
        choices: [
          {
            index: 0,
            message: data?.message || { role: "assistant", content: "" },
            finish_reason: "stop",
          },
        ],
      });
    } else {
      res.json(data);
    }

  } catch (err) {
    console.error("💥 relay error", err);
    res.status(500).json({ error: "relay_failed", detail: err.message });
  }
});

/* ------------------------------
   Start server
--------------------------------*/
app.listen(PORT, () => {
  console.log(`Relay listening on port ${PORT}`);
});