import express, { Request, Response } from "express";
import fs from "fs";
import path from "path";
import { storage } from "../storage";
import { classifyInternalChat } from "../ai/internal-chat-graph";
import { runInternalChatWorkflow, createAppointmentToday } from "../ai/internal-chat-workflow";
import { resolveAiProvider } from "../ai/llm-factory";

const CHAT_HISTORY_DIR = path.join(__dirname, "..", "..", "chat-history");

function getChatHistoryPath(userId: number): string {
  return path.join(CHAT_HISTORY_DIR, `user-${userId}.json`);
}

const router = express.Router();

// GET /api/ai/settings
router.get("/settings", async (req: Request, res: Response): Promise<any> => {
  try {
    const userId = req.user?.id;
    if (!userId) return res.status(401).json({ message: "Unauthorized" });

    const settings = await storage.getAiSettings(userId);
    if (!settings) return res.status(200).json(null);

    return res.status(200).json({
      id:               settings.id,
      apiKey:           settings.apiKey,
      aiEnabled:        settings.aiEnabled ?? true,
      openAiKey:        settings.openAiKey ?? "",
      openAiEnabled:    settings.openAiEnabled ?? false,
      openAiModel:      settings.openAiModel ?? "gpt-5.2",
      claudeAiKey:      settings.claudeAiKey ?? "",
      claudeAiEnabled:  settings.claudeAiEnabled ?? false,
      claudeAiModel:    settings.claudeAiModel ?? "claude-haiku-4-5-20251001",
      googleAiModel:    settings.googleAiModel ?? "gemini-2.5-flash",
      dentalMgmtKey:    settings.dentalMgmtKey ?? "",
      dentalMgmtEnabled: settings.dentalMgmtEnabled ?? false,
      openPhoneReply:   settings.openPhoneReply ?? false,
    });
  } catch (err) {
    return res.status(500).json({ error: "Failed to fetch AI settings", details: String(err) });
  }
});

// PUT /api/ai/settings
router.put("/settings", async (req: Request, res: Response): Promise<any> => {
  try {
    const userId = req.user?.id;
    if (!userId) return res.status(401).json({ message: "Unauthorized" });

    const { apiKey, aiEnabled } = req.body;
    if (!apiKey?.trim()) {
      return res.status(400).json({ message: "apiKey is required" });
    }

    const settings = await storage.upsertAiSettings(userId, apiKey.trim(), aiEnabled);
    return res.status(200).json({ id: settings.id, apiKey: settings.apiKey, aiEnabled: settings.aiEnabled ?? true });
  } catch (err) {
    return res.status(500).json({ error: "Failed to save AI settings", details: String(err) });
  }
});

// PUT /api/ai/enabled
router.put("/enabled", async (req: Request, res: Response): Promise<any> => {
  try {
    const userId = req.user?.id;
    if (!userId) return res.status(401).json({ message: "Unauthorized" });

    const { aiEnabled } = req.body;
    if (typeof aiEnabled !== "boolean") {
      return res.status(400).json({ message: "aiEnabled must be a boolean" });
    }

    await storage.setAiEnabled(userId, aiEnabled);
    return res.status(200).json({ aiEnabled });
  } catch (err) {
    return res.status(500).json({ error: "Failed to save AI enabled setting", details: String(err) });
  }
});

// PUT /api/ai/provider-key
router.put("/provider-key", async (req: Request, res: Response): Promise<any> => {
  try {
    const userId = req.user?.id;
    if (!userId) return res.status(401).json({ message: "Unauthorized" });

    const { provider, apiKey } = req.body;
    if (!["openAi", "claudeAi", "dentalMgmt"].includes(provider)) {
      return res.status(400).json({ message: "Invalid provider" });
    }
    if (!apiKey?.trim()) {
      return res.status(400).json({ message: "apiKey is required" });
    }

    await storage.upsertProviderKey(userId, provider, apiKey.trim());
    return res.status(200).json({ provider, apiKey: apiKey.trim() });
  } catch (err) {
    return res.status(500).json({ error: "Failed to save provider key", details: String(err) });
  }
});

// PUT /api/ai/provider-enabled
router.put("/provider-enabled", async (req: Request, res: Response): Promise<any> => {
  try {
    const userId = req.user?.id;
    if (!userId) return res.status(401).json({ message: "Unauthorized" });

    const { provider, enabled } = req.body;
    if (!["openAi", "claudeAi", "dentalMgmt"].includes(provider)) {
      return res.status(400).json({ message: "Invalid provider" });
    }
    if (typeof enabled !== "boolean") {
      return res.status(400).json({ message: "enabled must be a boolean" });
    }

    await storage.setProviderEnabled(userId, provider, enabled);
    return res.status(200).json({ provider, enabled });
  } catch (err) {
    return res.status(500).json({ error: "Failed to save provider enabled setting", details: String(err) });
  }
});

// PUT /api/ai/provider-model
router.put("/provider-model", async (req: Request, res: Response): Promise<any> => {
  try {
    const userId = req.user?.id;
    if (!userId) return res.status(401).json({ message: "Unauthorized" });

    const { provider, model } = req.body;
    if (!["claudeAi", "openAi", "googleAi"].includes(provider)) {
      return res.status(400).json({ message: "Invalid provider" });
    }
    if (!model?.trim()) {
      return res.status(400).json({ message: "model is required" });
    }

    await storage.setProviderModel(userId, provider, model.trim());
    return res.status(200).json({ provider, model: model.trim() });
  } catch (err) {
    return res.status(500).json({ error: "Failed to save provider model", details: String(err) });
  }
});

// GET /api/ai/advanced-settings
router.get("/advanced-settings", async (req: Request, res: Response): Promise<any> => {
  try {
    const userId = req.user?.id;
    if (!userId) return res.status(401).json({ message: "Unauthorized" });

    const openPhoneReply = await storage.getOpenPhoneReply(userId);
    return res.status(200).json({ openPhoneReply });
  } catch (err) {
    return res.status(500).json({ error: "Failed to fetch advanced settings", details: String(err) });
  }
});

// PUT /api/ai/advanced-settings
router.put("/advanced-settings", async (req: Request, res: Response): Promise<any> => {
  try {
    const userId = req.user?.id;
    if (!userId) return res.status(401).json({ message: "Unauthorized" });

    const { openPhoneReply } = req.body;
    if (typeof openPhoneReply !== "boolean") {
      return res.status(400).json({ message: "openPhoneReply must be a boolean" });
    }

    await storage.setOpenPhoneReply(userId, openPhoneReply);
    return res.status(200).json({ openPhoneReply });
  } catch (err) {
    return res.status(500).json({ error: "Failed to save advanced settings", details: String(err) });
  }
});

// GET /api/ai/chat-templates
router.get("/chat-templates", async (req: Request, res: Response): Promise<any> => {
  try {
    const userId = req.user?.id;
    if (!userId) return res.status(401).json({ message: "Unauthorized" });
    const templates = await storage.getAiChatTemplates(userId);
    return res.status(200).json(templates);
  } catch (err) {
    return res.status(500).json({ error: "Failed to fetch AI chat templates", details: String(err) });
  }
});

// PUT /api/ai/chat-templates
router.put("/chat-templates", async (req: Request, res: Response): Promise<any> => {
  try {
    const userId = req.user?.id;
    if (!userId) return res.status(401).json({ message: "Unauthorized" });
    const { reminderGreeting, newPatientGreeting, generalFallback, rescheduleGreeting, reminderSms } = req.body;
    await storage.saveAiChatTemplates(userId, { reminderGreeting, newPatientGreeting, generalFallback, rescheduleGreeting, reminderSms });
    const updated = await storage.getAiChatTemplates(userId);
    return res.status(200).json(updated);
  } catch (err) {
    return res.status(500).json({ error: "Failed to save AI chat templates", details: String(err) });
  }
});

// GET /api/ai/internal-chat-settings
router.get("/internal-chat-settings", async (req: Request, res: Response): Promise<any> => {
  try {
    const userId = req.user?.id;
    if (!userId) return res.status(401).json({ message: "Unauthorized" });
    const systemPrompt = await storage.getInternalChatSystemPrompt(userId);
    return res.status(200).json({ systemPrompt });
  } catch (err) {
    return res.status(500).json({ error: "Failed to fetch internal chat settings", details: String(err) });
  }
});

// PUT /api/ai/internal-chat-settings
router.put("/internal-chat-settings", async (req: Request, res: Response): Promise<any> => {
  try {
    const userId = req.user?.id;
    if (!userId) return res.status(401).json({ message: "Unauthorized" });
    const { systemPrompt } = req.body;
    if (typeof systemPrompt !== "string") return res.status(400).json({ message: "systemPrompt must be a string" });
    await storage.saveInternalChatSystemPrompt(userId, systemPrompt.trim());
    return res.status(200).json({ systemPrompt: systemPrompt.trim() });
  } catch (err) {
    return res.status(500).json({ error: "Failed to save internal chat settings", details: String(err) });
  }
});

// GET /api/ai/cdt-aliases
router.get("/cdt-aliases", async (req: Request, res: Response): Promise<any> => {
  try {
    const userId = req.user?.id;
    if (!userId) return res.status(401).json({ message: "Unauthorized" });
    const aliases = await storage.getCdtAliases(userId);
    return res.status(200).json(aliases);
  } catch (err) {
    return res.status(500).json({ error: "Failed to fetch CDT aliases", details: String(err) });
  }
});

// PUT /api/ai/cdt-aliases
router.put("/cdt-aliases", async (req: Request, res: Response): Promise<any> => {
  try {
    const userId = req.user?.id;
    if (!userId) return res.status(401).json({ message: "Unauthorized" });
    const aliases = req.body;
    if (!Array.isArray(aliases)) {
      return res.status(400).json({ message: "Body must be an array of { phrase, cdtCode }" });
    }
    const cleaned = aliases
      .filter((a: any) => typeof a?.phrase === "string" && typeof a?.cdtCode === "string")
      .map((a: any) => ({
        phrase: a.phrase.trim().toLowerCase(),
        cdtCode: a.cdtCode.trim().toUpperCase(),
      }));
    await storage.saveCdtAliases(userId, cleaned);
    return res.status(200).json(cleaned);
  } catch (err) {
    return res.status(500).json({ error: "Failed to save CDT aliases", details: String(err) });
  }
});

// POST /api/ai/cdt-aliases/add  — add/update a single alias without overwriting others
router.post("/cdt-aliases/add", async (req: Request, res: Response): Promise<any> => {
  try {
    const userId = req.user?.id;
    if (!userId) return res.status(401).json({ message: "Unauthorized" });
    const { phrase, cdtCode } = req.body;
    if (typeof phrase !== "string" || typeof cdtCode !== "string") {
      return res.status(400).json({ message: "Body must be { phrase, cdtCode }" });
    }
    const existing = await storage.getCdtAliases(userId);
    const newEntry = { phrase: phrase.trim().toLowerCase(), cdtCode: cdtCode.trim().toUpperCase() };
    const updated = [...existing.filter((a) => a.phrase !== newEntry.phrase), newEntry];
    await storage.saveCdtAliases(userId, updated);
    return res.status(200).json(newEntry);
  } catch (err) {
    return res.status(500).json({ error: "Failed to add CDT alias", details: String(err) });
  }
});

// POST /api/ai/internal-chat
router.post("/internal-chat", async (req: Request, res: Response): Promise<any> => {
  try {
    const userId = req.user?.id;
    if (!userId) return res.status(401).json({ message: "Unauthorized" });

    const { message, history, clientDate } = req.body;
    if (!message?.trim()) return res.status(400).json({ message: "message is required" });

    const aiSettings = await storage.getAiSettings(userId);
    const activeAi   = resolveAiProvider(aiSettings ?? {});
    if (!activeAi) {
      return res.status(200).json({
        reply: "AI is not configured. Please add an API key in AI Settings.",
      });
    }

    const [extraSystemPrompt, customAliases] = await Promise.all([
      storage.getInternalChatSystemPrompt(userId),
      storage.getCdtAliases(userId),
    ]);

    const classification = await classifyInternalChat(
      message.trim(),
      activeAi.key,
      extraSystemPrompt || undefined,
      Array.isArray(history) ? history : [],
      activeAi.provider,
      activeAi.model,
      typeof clientDate === "string" ? clientDate : undefined
    );

    const response = await runInternalChatWorkflow(classification, userId, storage, customAliases);
    return res.status(200).json(response);
  } catch (err) {
    return res.status(500).json({ error: "Internal chat error", details: String(err) });
  }
});

router.post("/create-appointment-today", async (req: Request, res: Response): Promise<any> => {
  try {
    const userId = req.user?.id;
    if (!userId) return res.status(401).json({ message: "Unauthorized" });
    const { patientId, date } = req.body;
    if (!patientId) return res.status(400).json({ message: "patientId is required" });
    const result = await createAppointmentToday(Number(patientId), userId, storage, date ?? undefined);
    if ("error" in result) return res.status(409).json({ message: result.error });
    return res.status(200).json(result);
  } catch (err) {
    return res.status(500).json({ error: "Failed to create appointment", details: String(err) });
  }
});

// ─── Chat history persistence (JSON file per user) ──────────────────────────

router.get("/chat-history", async (req: Request, res: Response): Promise<any> => {
  try {
    const userId = req.user?.id;
    if (!userId) return res.status(401).json({ message: "Unauthorized" });
    const filePath = getChatHistoryPath(userId);
    if (!fs.existsSync(filePath)) return res.status(200).json({ messages: [] });
    const raw = fs.readFileSync(filePath, "utf-8");
    return res.status(200).json(JSON.parse(raw));
  } catch (err) {
    return res.status(500).json({ error: "Failed to load chat history", details: String(err) });
  }
});

router.put("/chat-history", async (req: Request, res: Response): Promise<any> => {
  try {
    const userId = req.user?.id;
    if (!userId) return res.status(401).json({ message: "Unauthorized" });
    const { messages } = req.body;
    if (!Array.isArray(messages)) return res.status(400).json({ message: "messages array is required" });
    if (!fs.existsSync(CHAT_HISTORY_DIR)) fs.mkdirSync(CHAT_HISTORY_DIR, { recursive: true });
    fs.writeFileSync(getChatHistoryPath(userId), JSON.stringify({ messages }, null, 2));
    return res.status(200).json({ ok: true });
  } catch (err) {
    return res.status(500).json({ error: "Failed to save chat history", details: String(err) });
  }
});

router.delete("/chat-history", async (req: Request, res: Response): Promise<any> => {
  try {
    const userId = req.user?.id;
    if (!userId) return res.status(401).json({ message: "Unauthorized" });
    const filePath = getChatHistoryPath(userId);
    if (fs.existsSync(filePath)) fs.unlinkSync(filePath);
    return res.status(200).json({ ok: true });
  } catch (err) {
    return res.status(500).json({ error: "Failed to clear chat history", details: String(err) });
  }
});

export default router;