import LocationHistory from "../model/locationHistory.model";
import User from "../model/user.model";
import { Request, Response } from "express";

// Helper to get current date in YYYY-MM-DD format
const getTodayDateString = (): string => {
  const now = new Date();
  return now.toISOString().split('T')[0];
};

// GET /location/users/latest
export const getAllUsersLatest = async (req: Request, res: Response) => {
  try {
    const users = await User.find({ isActive: true }).select('location lastActive username profilePhoto role');
    return res.json(users.filter(u => u.location && u.location.coordinates && u.location.coordinates.length === 2));
  } catch (err) {
    console.error(err);
    return res.status(500).json({ message: 'Server error' });
  }
};

export const updateLocation = async (req: Request, res: Response) => {
  try {
    const userId = req.userId;
    const { longitude, latitude } = req.body;

    if (!longitude || !latitude) {
      return res.status(400).json({ message: "Location missing" });
    }

    const today = getTodayDateString();
    const coordinates: [number, number] = [longitude, latitude];

    // 1) Update latest location in User model
    await User.findByIdAndUpdate(userId, {
      location: {
        type: "Point",
        coordinates
      },
      lastActive: new Date()
    });

    // 2) Upsert location history for today
    await LocationHistory.findOneAndUpdate(
      { user: userId, date: today },
      {
        $push: {
          locations: {
            coordinates,
            timestamp: new Date()
          }
        },
        $set: {
          lastLocation: {
            type: "Point",
            coordinates
          }
        }
      },
      { upsert: true, new: true }
    );

    return res.json({ message: "Location updated" });
  } catch (err) {
    console.error(err);
    return res.status(500).json({ message: "Server error" });
  }
};

// Get user's location history for a specific date
export const getLocationHistory = async (req: Request, res: Response) => {
  try {
    const userId = req.userId;
    const { date } = req.query; // Expected format: YYYY-MM-DD

    if (!date || typeof date !== 'string') {
      return res.status(400).json({ message: "Date required (YYYY-MM-DD)" });
    }

    const history = await LocationHistory.findOne({ user: userId, date });

    if (!history) {
      return res.status(404).json({ message: "No location data for this date" });
    }

    return res.json({
      date: history.date,
      locations: history.locations,
      totalPoints: history.locations.length
    });
  } catch (err) {
    console.error(err);
    return res.status(500).json({ message: "Server error" });
  }
};

// Get user's location history for a date range
export const getLocationHistoryRange = async (req: Request, res: Response) => {
  try {
    const userId = req.userId;
    const { startDate, endDate } = req.query;

    if (!startDate || !endDate || typeof startDate !== 'string' || typeof endDate !== 'string') {
      return res.status(400).json({ message: "startDate and endDate required (YYYY-MM-DD)" });
    }

    const history = await LocationHistory.find({
      user: userId,
      date: { $gte: startDate, $lte: endDate }
    }).sort({ date: 1 });

    return res.json({
      days: history.length,
      history: history.map(h => ({
        date: h.date,
        locationCount: h.locations.length,
        lastLocation: h.lastLocation
      }))
    });
  } catch (err) {
    console.error(err);
    return res.status(500).json({ message: "Server error" });
  }
};

// Get nearby users based on their last known location
export const getNearbyUsers = async (req: Request, res: Response) => {
  try {
    const userId = req.userId;
    const { maxDistance = 5000 } = req.query; // default 5km

    const user = await User.findById(userId);
    if (!user?.location) {
      return res.status(400).json({ message: "User location not set" });
    }

    const nearbyUsers = await User.find({
      _id: { $ne: userId },
      location: {
        $near: {
          $geometry: user.location,
          $maxDistance: Number(maxDistance)
        }
      }
    }).limit(20).select('username profilePhoto location role');

    return res.json({ nearbyUsers });
  } catch (err) {
    console.error(err);
    return res.status(500).json({ message: "Server error" });
  }
};