import { FastifyInstance } from "fastify";
import nodemailer from "nodemailer";
import { db } from "../db/client.js";
import { userSettings } from "../db/schema.js";
import { eq } from "drizzle-orm";
import { requireAuth, getAnonymousUserId } from "../plugins/auth.js";
import { env } from "../plugins/env.js";
import type { AuthUser } from "../types/fastify.js";
import type { Language } from "../i18n/translations.js";

// Exported type for use in schedulers
export type UserSettings = {
  userId: number;
  emailEnabled: boolean;
  notificationEmail: string | null;
  emailStockReminders: boolean;
  emailIntakeReminders: boolean;
  shoutrrrEnabled: boolean;
  shoutrrrUrl: string | null;
  shoutrrrStockReminders: boolean;
  shoutrrrIntakeReminders: boolean;
  reminderDaysBefore: number;
  repeatDailyReminders: boolean;
  skipRemindersForTakenDoses: boolean;
  repeatRemindersEnabled: boolean;
  reminderRepeatIntervalMinutes: number;
  maxNaggingReminders: number;
  lowStockDays: number;
  normalStockDays: number;
  highStockDays: number;
  language: Language;
  stockCalculationMode: "automatic" | "manual";
  lastAutoEmailSent: string | null;
  lastNotificationType: string | null;
  lastNotificationChannel: string | null;
};

type SettingsBody = {
  emailEnabled: boolean;
  notificationEmail: string;
  reminderDaysBefore: number;
  repeatDailyReminders: boolean;
  lowStockDays: number;
  normalStockDays: number;
  highStockDays: number;
  shoutrrrEnabled: boolean;
  shoutrrrUrl: string;
  emailStockReminders: boolean;
  emailIntakeReminders: boolean;
  shoutrrrStockReminders: boolean;
  shoutrrrIntakeReminders: boolean;
  skipRemindersForTakenDoses: boolean;
  repeatRemindersEnabled: boolean;
  reminderRepeatIntervalMinutes: number;
  maxNaggingReminders: number;
  language: string;
  stockCalculationMode: "automatic" | "manual";
};

type TestEmailBody = {
  email: string;
};

type TestShoutrrrBody = {
  url: string;
};

// Helper to parse boolean env vars
function envBool(key: string, defaultVal: boolean): boolean {
  const val = process.env[key];
  if (val === undefined) return defaultVal;
  return val === "true" || val === "1";
}

// Helper to parse integer env vars
function envInt(key: string, defaultVal: number): number {
  const val = process.env[key];
  if (val === undefined) return defaultVal;
  const parsed = parseInt(val, 10);
  return isNaN(parsed) ? defaultVal : parsed;
}

// Default settings for new users - read from ENV with fallbacks
function getDefaultSettings() {
  return {
    emailEnabled: envBool("DEFAULT_EMAIL_ENABLED", false),
    notificationEmail: process.env.DEFAULT_NOTIFICATION_EMAIL || null,
    emailStockReminders: envBool("DEFAULT_EMAIL_STOCK_REMINDERS", true),
    emailIntakeReminders: envBool("DEFAULT_EMAIL_INTAKE_REMINDERS", true),
    shoutrrrEnabled: envBool("DEFAULT_SHOUTRRR_ENABLED", false),
    shoutrrrUrl: process.env.DEFAULT_SHOUTRRR_URL || null,
    shoutrrrStockReminders: envBool("DEFAULT_SHOUTRRR_STOCK_REMINDERS", true),
    shoutrrrIntakeReminders: envBool("DEFAULT_SHOUTRRR_INTAKE_REMINDERS", true),
    reminderDaysBefore: envInt("REMINDER_DAYS_BEFORE", 7),
    repeatDailyReminders: envBool("DEFAULT_REPEAT_DAILY_REMINDERS", false),
    skipRemindersForTakenDoses: envBool("DEFAULT_SKIP_REMINDERS_FOR_TAKEN_DOSES", false),
    repeatRemindersEnabled: envBool("DEFAULT_REPEAT_REMINDERS_ENABLED", false),
    reminderRepeatIntervalMinutes: envInt("DEFAULT_REMINDER_REPEAT_INTERVAL_MINUTES", 30),
    maxNaggingReminders: envInt("DEFAULT_MAX_NAGGING_REMINDERS", 5),
    lowStockDays: envInt("DEFAULT_LOW_STOCK_DAYS", 30),
    normalStockDays: envInt("DEFAULT_NORMAL_STOCK_DAYS", 90),
    highStockDays: envInt("DEFAULT_HIGH_STOCK_DAYS", 180),
    language: (process.env.DEFAULT_LANGUAGE as "en" | "de") || "en",
    stockCalculationMode: (process.env.DEFAULT_STOCK_CALCULATION_MODE as "automatic" | "manual") || "automatic",
    lastAutoEmailSent: null,
    lastNotificationType: null,
    lastNotificationChannel: null,
  };
}

// Helper to get or create user settings
async function getOrCreateUserSettings(userId: number) {
  let [settings] = await db.select().from(userSettings).where(eq(userSettings.userId, userId));
  
  if (!settings) {
    // Create default settings for user (using ENV defaults)
    [settings] = await db.insert(userSettings).values({
      userId,
      ...getDefaultSettings(),
    }).returning();
  }
  
  return settings;
}

// Export for use in reminder scheduler
export async function loadUserSettings(userId: number): Promise<UserSettings> {
  const settings = await getOrCreateUserSettings(userId);
  return {
    userId: settings.userId,
    emailEnabled: settings.emailEnabled,
    notificationEmail: settings.notificationEmail,
    emailStockReminders: settings.emailStockReminders,
    emailIntakeReminders: settings.emailIntakeReminders,
    shoutrrrEnabled: settings.shoutrrrEnabled,
    shoutrrrUrl: settings.shoutrrrUrl,
    shoutrrrStockReminders: settings.shoutrrrStockReminders,
    shoutrrrIntakeReminders: settings.shoutrrrIntakeReminders,
    reminderDaysBefore: settings.reminderDaysBefore,
    repeatDailyReminders: settings.repeatDailyReminders,
    skipRemindersForTakenDoses: settings.skipRemindersForTakenDoses ?? false,
    repeatRemindersEnabled: settings.repeatRemindersEnabled ?? false,
    reminderRepeatIntervalMinutes: settings.reminderRepeatIntervalMinutes ?? 30,
    maxNaggingReminders: settings.maxNaggingReminders ?? 5,
    lowStockDays: settings.lowStockDays,
    normalStockDays: settings.normalStockDays,
    highStockDays: settings.highStockDays,
    language: settings.language as Language,
    stockCalculationMode: (settings.stockCalculationMode as "automatic" | "manual") ?? "automatic",
    lastAutoEmailSent: settings.lastAutoEmailSent,
    lastNotificationType: settings.lastNotificationType,
    lastNotificationChannel: settings.lastNotificationChannel,
  };
}

// Get all users with settings for scheduler
export async function getAllUserSettings(): Promise<UserSettings[]> {
  const allSettings = await db.select().from(userSettings);
  return allSettings.map(settings => ({
    userId: settings.userId,
    emailEnabled: settings.emailEnabled,
    notificationEmail: settings.notificationEmail,
    emailStockReminders: settings.emailStockReminders,
    emailIntakeReminders: settings.emailIntakeReminders,
    shoutrrrEnabled: settings.shoutrrrEnabled,
    shoutrrrUrl: settings.shoutrrrUrl,
    shoutrrrStockReminders: settings.shoutrrrStockReminders,
    shoutrrrIntakeReminders: settings.shoutrrrIntakeReminders,
    reminderDaysBefore: settings.reminderDaysBefore,
    repeatDailyReminders: settings.repeatDailyReminders,
    skipRemindersForTakenDoses: settings.skipRemindersForTakenDoses ?? false,
    repeatRemindersEnabled: settings.repeatRemindersEnabled ?? false,
    reminderRepeatIntervalMinutes: settings.reminderRepeatIntervalMinutes ?? 30,
    maxNaggingReminders: settings.maxNaggingReminders ?? 5,
    lowStockDays: settings.lowStockDays,
    normalStockDays: settings.normalStockDays,
    highStockDays: settings.highStockDays,
    language: settings.language as Language,
    stockCalculationMode: (settings.stockCalculationMode as "automatic" | "manual") ?? "automatic",
    lastAutoEmailSent: settings.lastAutoEmailSent,
    lastNotificationType: settings.lastNotificationType,
    lastNotificationChannel: settings.lastNotificationChannel,
  }));
}

export async function settingsRoutes(app: FastifyInstance) {
  // All settings routes require auth
  app.addHook("preHandler", requireAuth);

  // Helper to get user ID from request
  // Returns anonymous user ID when auth is disabled
  async function getUserId(request: any, reply: any): Promise<number> {
    // If auth is disabled, use the anonymous user
    if (!env.AUTH_ENABLED) {
      return getAnonymousUserId();
    }
    
    const authUser = request.user as unknown as AuthUser | null;
    if (!authUser) {
      reply.status(401).send({ error: "Not authenticated" });
      throw new Error("AUTH_REQUIRED");
    }
    return authUser.id;
  }

  // Get settings for current user
  app.get("/settings", async (request, reply) => {
    const userId = await getUserId(request, reply);

    const settings = await getOrCreateUserSettings(userId);
    
    return reply.send({
      // User notification settings (from DB)
      emailEnabled: settings.emailEnabled,
      notificationEmail: settings.notificationEmail ?? "",
      reminderDaysBefore: settings.reminderDaysBefore,
      repeatDailyReminders: settings.repeatDailyReminders,
      lowStockDays: settings.lowStockDays,
      normalStockDays: settings.normalStockDays,
      highStockDays: settings.highStockDays,
      shoutrrrEnabled: settings.shoutrrrEnabled,
      shoutrrrUrl: settings.shoutrrrUrl ?? "",
      emailStockReminders: settings.emailStockReminders,
      emailIntakeReminders: settings.emailIntakeReminders,
      shoutrrrStockReminders: settings.shoutrrrStockReminders,
      shoutrrrIntakeReminders: settings.shoutrrrIntakeReminders,
      skipRemindersForTakenDoses: settings.skipRemindersForTakenDoses,
      repeatRemindersEnabled: settings.repeatRemindersEnabled ?? false,
      reminderRepeatIntervalMinutes: settings.reminderRepeatIntervalMinutes ?? 30,
      maxNaggingReminders: settings.maxNaggingReminders ?? 5,
      language: settings.language,
      stockCalculationMode: settings.stockCalculationMode ?? "automatic",
      // SMTP settings (from .env - shared/server-configured)
      smtpHost: process.env.SMTP_HOST ?? "",
      smtpPort: parseInt(process.env.SMTP_PORT ?? "587"),
      smtpUser: process.env.SMTP_USER ?? "",
      smtpFrom: process.env.SMTP_FROM ?? "",
      smtpSecure: process.env.SMTP_SECURE === "true",
      hasSmtpPassword: !!(process.env.SMTP_TOKEN || process.env.SMTP_PASS),
      // Reminder state for this user
      lastAutoEmailSent: settings.lastAutoEmailSent,
      lastNotificationType: settings.lastNotificationType,
      lastNotificationChannel: settings.lastNotificationChannel,
      // Server settings (from .env, read-only)
      expiryWarningDays: parseInt(process.env.EXPIRY_WARNING_DAYS ?? "30", 10),
    });
  });

  // Update settings for current user
  app.put<{ Body: SettingsBody }>("/settings", async (request, reply) => {
    const userId = await getUserId(request, reply);

    const body = request.body;
    
    // Check if any stock reminders are configured
    const hasEmailStock = body.emailEnabled && body.emailStockReminders && body.notificationEmail;
    const hasShoutrrrStock = body.shoutrrrEnabled && body.shoutrrrStockReminders && body.shoutrrrUrl;
    const hasAnyStockReminder = hasEmailStock || hasShoutrrrStock;
    
    // Disable repeatDailyReminders if no stock reminders are configured
    const repeatDailyReminders = hasAnyStockReminder ? (body.repeatDailyReminders ?? false) : false;

    // Update or insert user settings
    const existingSettings = await db.select().from(userSettings).where(eq(userSettings.userId, userId));
    
    const settingsData = {
      emailEnabled: body.emailEnabled,
      notificationEmail: body.notificationEmail || null,
      emailStockReminders: body.emailStockReminders ?? true,
      emailIntakeReminders: body.emailIntakeReminders ?? true,
      shoutrrrEnabled: body.shoutrrrEnabled ?? false,
      shoutrrrUrl: body.shoutrrrUrl || null,
      shoutrrrStockReminders: body.shoutrrrStockReminders ?? true,
      shoutrrrIntakeReminders: body.shoutrrrIntakeReminders ?? true,
      reminderDaysBefore: body.reminderDaysBefore,
      repeatDailyReminders,
      skipRemindersForTakenDoses: body.skipRemindersForTakenDoses ?? false,
      repeatRemindersEnabled: body.repeatRemindersEnabled ?? false,
      reminderRepeatIntervalMinutes: body.reminderRepeatIntervalMinutes ?? 30,
      maxNaggingReminders: body.maxNaggingReminders ?? 5,
      lowStockDays: body.lowStockDays ?? 30,
      normalStockDays: body.normalStockDays ?? 90,
      highStockDays: body.highStockDays ?? 180,
      language: body.language ?? "en",
      stockCalculationMode: body.stockCalculationMode ?? "automatic",
      updatedAt: new Date(),
    };

    if (existingSettings.length > 0) {
      await db.update(userSettings)
        .set(settingsData)
        .where(eq(userSettings.userId, userId));
    } else {
      await db.insert(userSettings).values({
        userId: userId,
        ...settingsData,
      });
    }

    return reply.send({ success: true });
  });

  // Test email - use SMTP settings from process.env
  app.post<{ Body: TestEmailBody }>("/settings/test-email", async (request, reply) => {
    const { email } = request.body;
    
    const smtpHost = process.env.SMTP_HOST;
    const smtpUser = process.env.SMTP_USER;
    const smtpPass = process.env.SMTP_TOKEN || process.env.SMTP_PASS;
    const smtpPort = parseInt(process.env.SMTP_PORT ?? "587");
    const smtpSecure = process.env.SMTP_SECURE === "true";
    const smtpFrom = process.env.SMTP_FROM ?? smtpUser;

    if (!smtpHost || !smtpUser) {
      return reply.status(400).send({ error: "SMTP not configured" });
    }

    try {
      const transporter = nodemailer.createTransport({
        host: smtpHost,
        port: smtpPort,
        secure: smtpSecure,
        auth: {
          user: smtpUser,
          pass: smtpPass ?? "",
        },
      });

      await transporter.sendMail({
        from: smtpFrom,
        to: email,
        subject: "MedAssist-ng - Test Email",
        text: "This is a test email from MedAssist-ng. If you received this, your email configuration is working correctly!",
        html: `
          <div style="font-family: system-ui, sans-serif; max-width: 600px; margin: 0 auto; padding: 20px;">
            <h2 style="color: #2563eb;">MedAssist-ng - Test Email</h2>
            <p>This is a test email from MedAssist-ng.</p>
            <p style="color: #10b981; font-weight: 600;">✓ If you received this, your email configuration is working correctly!</p>
            <hr style="border: none; border-top: 1px solid #e5e7eb; margin: 20px 0;" />
            <p style="color: #6b7280; font-size: 14px;">Sent from MedAssist-ng Medication Planner</p>
          </div>
        `,
      });

      return reply.send({ success: true, message: "Test email sent successfully" });
    } catch (error) {
      const errorMessage = error instanceof Error ? error.message : "Unknown error";
      return reply.status(500).send({ error: `Failed to send email: ${errorMessage}` });
    }
  });

  // Test Shoutrrr/ntfy notification
  app.post<{ Body: TestShoutrrrBody }>("/settings/test-shoutrrr", async (request, reply) => {
    const { url } = request.body;
    
    if (!url) {
      return reply.status(400).send({ error: "Notification URL is required" });
    }

    try {
      const result = await sendShoutrrrNotification(url, "MedAssist-ng Test", "This is a test notification from MedAssist-ng. If you received this, your notification configuration is working correctly!");
      
      if (result.success) {
        return reply.send({ success: true, message: "Test notification sent successfully" });
      } else {
        return reply.status(500).send({ error: result.error });
      }
    } catch (error) {
      const errorMessage = error instanceof Error ? error.message : "Unknown error";
      return reply.status(500).send({ error: `Failed to send notification: ${errorMessage}` });
    }
  });
}

// Validate URL to prevent SSRF attacks
function isAllowedNotificationUrl(urlStr: string): { allowed: boolean; error?: string } {
  try {
    // Convert ntfy:// to https:// for parsing
    const normalizedUrl = urlStr.startsWith("ntfy://") 
      ? urlStr.replace("ntfy://", "https://") 
      : urlStr;
    
    const parsed = new URL(normalizedUrl);
    
    // Only allow http and https protocols
    if (!['http:', 'https:'].includes(parsed.protocol)) {
      return { allowed: false, error: "Only HTTP/HTTPS protocols are allowed" };
    }
    
    // Block private/internal IP addresses
    const hostname = parsed.hostname.toLowerCase();
    
    // Block localhost
    if (hostname === 'localhost' || hostname === '127.0.0.1' || hostname === '::1') {
      return { allowed: false, error: "Localhost URLs are not allowed" };
    }
    
    // Block private IP ranges (basic check)
    const ipMatch = hostname.match(/^(\d+)\.(\d+)\.(\d+)\.(\d+)$/);
    if (ipMatch) {
      const [, a, b] = ipMatch.map(Number);
      // 10.x.x.x, 172.16-31.x.x, 192.168.x.x, 169.254.x.x (link-local)
      if (a === 10 || a === 127 || (a === 172 && b >= 16 && b <= 31) || 
          (a === 192 && b === 168) || (a === 169 && b === 254)) {
        return { allowed: false, error: "Private IP addresses are not allowed" };
      }
    }
    
    // Block common internal hostnames
    if (hostname.endsWith('.local') || hostname.endsWith('.internal') || 
        hostname.endsWith('.lan') || hostname === 'metadata.google.internal') {
      return { allowed: false, error: "Internal hostnames are not allowed" };
    }
    
    return { allowed: true };
  } catch {
    return { allowed: false, error: "Invalid URL format" };
  }
}

// Send notification via Shoutrrr-compatible URL (supports ntfy, Discord, Telegram, etc.)
export async function sendShoutrrrNotification(urlStr: string, title: string, message: string): Promise<{ success: boolean; error?: string }> {
  try {
    // Validate URL to prevent SSRF
    const validation = isAllowedNotificationUrl(urlStr);
    if (!validation.allowed) {
      return { success: false, error: validation.error };
    }
    
    let targetUrl: string;
    let method = "POST";
    let headers: Record<string, string> = {};
    let body: string | undefined;

    // Remove emojis from title for header compatibility
    const cleanTitle = title.replace(/[\u{1F300}-\u{1F9FF}]|[\u{2600}-\u{26FF}]|[\u{2700}-\u{27BF}]|[\u{FE00}-\u{FE0F}]|[\u{2000}-\u{206F}]|⚠|️/gu, "").trim();

    if (urlStr.startsWith("ntfy://")) {
      const parsed = new URL(urlStr.replace("ntfy://", "https://"));
      targetUrl = `https://${parsed.host}${parsed.pathname}`;
      headers = { "Title": cleanTitle, "Tags": "pill" };
      body = message;
      
      if (parsed.username && parsed.password) {
        headers["Authorization"] = "Basic " + Buffer.from(`${parsed.username}:${parsed.password}`).toString("base64");
      }
    } else if (urlStr.startsWith("https://ntfy.") || urlStr.includes("ntfy.sh") || urlStr.includes("/ntfy/")) {
      targetUrl = urlStr;
      headers = { "Title": cleanTitle, "Tags": "pill" };
      body = message;
    } else if (urlStr.startsWith("http://") || urlStr.startsWith("https://")) {
      targetUrl = urlStr;
      headers = { "Content-Type": "application/json" };
      body = JSON.stringify({ title, message, text: `${title}\n\n${message}` });
    } else {
      return { success: false, error: "Unsupported URL format. Use ntfy:// or https:// URL" };
    }

    const response = await fetch(targetUrl, {
      method,
      headers,
      body,
    });

    if (response.ok) {
      return { success: true };
    } else {
      const errorText = await response.text();
      return { success: false, error: `HTTP ${response.status}: ${errorText}` };
    }
  } catch (error) {
    const errorMessage = error instanceof Error ? error.message : "Unknown error";
    return { success: false, error: errorMessage };
  }
}