import { Request, Response } from 'express';
import EventDay from '../model/eventDay.model';
import Event from '../model/event.model';
import User from '../model/user.model';
import { uploadEventPhoto, deleteEventPhoto, calculateAttendanceStats, generateEventDays } from '../util/eventDay.util';
import { canManageEventDay } from '../util/role.util';

interface IEventDayRequest extends Request {
    userId?: string;
}

// ==================== GET ALL DAYS FOR AN EVENT ====================
export const getEventDays = async (req: IEventDayRequest, res: Response) => {
    try {
        const { eventId } = req.params;
        const userId = req.userId;

        // Verify event exists
        const event = await Event.findById(eventId);
        if (!event) {
            return res.status(404).json({ message: 'Event not found' });
        }

        // Check if user is participant or creator
        const isCreator = event.createdBy.toString() === userId;
        const isParticipant = event.participants.some(p => p.user.toString() === userId);

        if (!isCreator && !isParticipant) {
            return res.status(403).json({ message: 'Access denied. You must be a participant or creator.' });
        }

        // Get all event days
        let eventDays = await EventDay.find({ event: eventId })
            .sort({ dayNumber: 1 })
            .populate('attendance.user', 'username profilePhoto')
            .populate('photos.uploadedBy', 'username');

        // Auto-generate event days if they don't exist (for existing events)
        if (eventDays.length === 0) {
            try {
                await generateEventDays(event);
                eventDays = await EventDay.find({ event: eventId })
                    .sort({ dayNumber: 1 })
                    .populate('attendance.user', 'username profilePhoto')
                    .populate('photos.uploadedBy', 'username');
            } catch (err) {
                console.error('Failed to auto-generate event days:', err);
            }
        }

        // Calculate stats
        const stats = await calculateAttendanceStats(eventId);

        return res.json({
            eventDays: eventDays.map(day => {
                const now = new Date();
                const eventEndTime = new Date(day.endTime);

                // Determine status
                let status: 'green' | 'red' | 'blue';
                if (day.isCompleted && day.photos.length > 0 && day.attendance.length > 0) {
                    status = 'green';
                } else if (eventEndTime < now && (!day.hasStarted || day.photos.length === 0 || day.attendance.length === 0)) {
                    status = 'red';
                } else {
                    status = 'blue';
                }

                return {
                    _id: day._id,
                    date: day.date,
                    dayNumber: day.dayNumber,
                    startTime: day.startTime,
                    endTime: day.endTime,
                    photoCount: day.photos.length,
                    attendanceCount: day.attendance.length,
                    hasStarted: day.hasStarted,
                    isCompleted: day.isCompleted,
                    status,
                    notes: day.notes,
                    weatherCondition: day.weatherCondition,
                    // Only show full details to creator
                    ...(isCreator && {
                        photos: day.photos,
                        attendance: day.attendance,
                        activitiesConducted: day.activitiesConducted,
                        incidentsReported: day.incidentsReported,
                        equipmentUsed: day.equipmentUsed
                    })
                };
            }),
            stats
        });
    } catch (err: any) {
        console.error(err);
        return res.status(500).json({ message: 'Server error', error: err.message });
    }
};

// ==================== GET SPECIFIC DAY DETAILS ====================
export const getEventDayDetails = async (req: IEventDayRequest, res: Response) => {
    try {
        const { eventDayId } = req.params;
        const userId = req.userId;

        const eventDay = await EventDay.findById(eventDayId)
            .populate('event')
            .populate('attendance.user', 'username email profilePhoto')
            .populate('attendance.verifiedBy', 'username')
            .populate('photos.uploadedBy', 'username profilePhoto');

        if (!eventDay) {
            return res.status(404).json({ message: 'Event day not found' });
        }

        const event = eventDay.event as any;
        const isCreator = event.createdBy.toString() === userId;
        const isParticipant = event.participants.some((p: any) => p.user.toString() === userId);

        if (!isCreator && !isParticipant) {
            return res.status(403).json({ message: 'Access denied' });
        }

        const now = new Date();
        const eventEndTime = new Date(eventDay.endTime);
        let status: 'green' | 'red' | 'blue';

        if (eventDay.isCompleted && eventDay.photos.length > 0 && eventDay.attendance.length > 0) {
            status = 'green';
        } else if (eventEndTime < now && (!eventDay.hasStarted || eventDay.photos.length === 0 || eventDay.attendance.length === 0)) {
            status = 'red';
        } else {
            status = 'blue';
        }

        const response: any = {
            _id: eventDay._id,
            event: {
                _id: event._id,
                title: event.title,
                code: event.code
            },
            date: eventDay.date,
            dayNumber: eventDay.dayNumber,
            startTime: eventDay.startTime,
            endTime: eventDay.endTime,
            hasStarted: eventDay.hasStarted,
            isCompleted: eventDay.isCompleted,
            status,
            photos: eventDay.photos,
            notes: eventDay.notes,
            weatherCondition: eventDay.weatherCondition
        };

        if (isCreator) {
            response.attendance = eventDay.attendance;
            response.activitiesConducted = eventDay.activitiesConducted;
            response.incidentsReported = eventDay.incidentsReported;
            response.equipmentUsed = eventDay.equipmentUsed;
            response.completedAt = eventDay.completedAt;
        } else {
            // Show only user's own attendance
            response.myAttendance = eventDay.attendance.find(
                (a: any) => a.user._id.toString() === userId
            );
        }

        return res.json(response);
    } catch (err: any) {
        console.error(err);
        return res.status(500).json({ message: 'Server error', error: err.message });
    }
};

// ==================== UPLOAD DAY PHOTOS ====================
export const uploadDayPhotos = async (req: IEventDayRequest, res: Response) => {
    try {
        const { eventDayId } = req.params;
        const userId = req.userId;
        const files = req.files as Express.Multer.File[];
        const { captions } = req.body; // Array of captions (optional)

        if (!files || files.length === 0) {
            return res.status(400).json({ message: 'No files uploaded' });
        }

        const eventDay = await EventDay.findById(eventDayId).populate('event');
        if (!eventDay) {
            return res.status(404).json({ message: 'Event day not found' });
        }

        const event = eventDay.event as any;
        const user = await User.findById(userId);

        if (!user) {
            return res.status(404).json({ message: 'User not found' });
        }

        // Check if user can manage this event day (trainer+ level from same org)
        const canManage = await canManageEventDay(user, event);
        if (!canManage) {
            return res.status(403).json({
                message: 'Only trainers, organizations, and admins from the same organization can upload photos'
            });
        }

        // Upload each file to Cloudinary
        const uploadedPhotos = [];
        const captionsArray = captions ? (Array.isArray(captions) ? captions : [captions]) : [];

        for (let i = 0; i < files.length; i++) {
            const file = files[i];
            const caption = captionsArray[i] || undefined;

            try {
                const { url, publicId } = await uploadEventPhoto(
                    file,
                    event._id.toString(),
                    eventDay.dayNumber
                );

                const photo = {
                    url,
                    publicId,
                    caption,
                    uploadedBy: userId as any,
                    uploadedAt: new Date()
                };

                eventDay.photos.push(photo as any);
                uploadedPhotos.push(photo);
            } catch (uploadErr) {
                console.error('Failed to upload photo:', uploadErr);
            }
        }

        // Auto-start event day when first photo is uploaded
        if (!eventDay.hasStarted && uploadedPhotos.length > 0) {
            eventDay.hasStarted = true;
        }

        await eventDay.save();

        return res.json({
            message: `${uploadedPhotos.length} photo(s) uploaded successfully`,
            photos: uploadedPhotos
        });
    } catch (err: any) {
        console.error(err);
        return res.status(500).json({ message: 'Server error', error: err.message });
    }
};

// ==================== DELETE DAY PHOTO ====================
export const deleteDayPhoto = async (req: IEventDayRequest, res: Response) => {
    try {
        const { eventDayId, photoId } = req.params;
        const userId = req.userId;

        const eventDay = await EventDay.findById(eventDayId).populate('event');
        if (!eventDay) {
            return res.status(404).json({ message: 'Event day not found' });
        }

        const event = eventDay.event as any;
        const user = await User.findById(userId);

        if (!user) {
            return res.status(404).json({ message: 'User not found' });
        }

        // Check if user can manage this event day
        const canManage = await canManageEventDay(user, event);
        if (!canManage) {
            return res.status(403).json({
                message: 'Only trainers, organizations, and admins from the same organization can delete photos'
            });
        }

        const photo = eventDay.photos.find((p: any) => p._id.toString() === photoId);
        if (!photo) {
            return res.status(404).json({ message: 'Photo not found' });
        }

        // Delete from Cloudinary
        try {
            await deleteEventPhoto(photo.publicId);
        } catch (cloudinaryErr) {
            console.error('Failed to delete from Cloudinary:', cloudinaryErr);
        }

        // Remove from database
        eventDay.photos = eventDay.photos.filter((p: any) => p._id.toString() !== photoId) as any;
        await eventDay.save();

        return res.json({ message: 'Photo deleted successfully' });
    } catch (err: any) {
        console.error(err);
        return res.status(500).json({ message: 'Server error', error: err.message });
    }
};

// ==================== MARK ATTENDANCE ====================
export const markAttendance = async (req: IEventDayRequest, res: Response) => {
    try {
        const { eventDayId } = req.params;
        const currentUserId = req.userId;
        const { userId, checkInMethod, latitude, longitude } = req.body;

        if (!userId || !checkInMethod) {
            return res.status(400).json({ message: 'userId and checkInMethod required' });
        }

        const eventDay = await EventDay.findById(eventDayId).populate('event');
        if (!eventDay) {
            return res.status(404).json({ message: 'Event day not found' });
        }

        const event = eventDay.event as any;
        const user = await User.findById(currentUserId);

        if (!user) {
            return res.status(404).json({ message: 'User not found' });
        }

        // Check if user can manage this event day
        const canManage = await canManageEventDay(user, event);
        if (!canManage) {
            return res.status(403).json({
                message: 'Only trainers, organizations, and admins from the same organization can mark attendance'
            });
        }

        // Check if user is a participant
        const isParticipant = event.participants.some((p: any) => p.user.toString() === userId);
        if (!isParticipant) {
            return res.status(400).json({ message: 'User is not a participant of this event' });
        }

        // Check if already marked
        const existingAttendance = eventDay.attendance.find((a: any) => a.user.toString() === userId);
        if (existingAttendance) {
            return res.status(400).json({ message: 'Attendance already marked for this user' });
        }

        // Create attendance record
        const attendance: any = {
            user: userId,
            checkInTime: new Date(),
            checkInMethod,
            verifiedBy: checkInMethod === 'manual' ? currentUserId : undefined
        };

        // Add location if provided
        if (latitude && longitude) {
            attendance.checkInLocation = {
                type: 'Point',
                coordinates: [parseFloat(longitude), parseFloat(latitude)]
            };
        }

        eventDay.attendance.push(attendance);
        await eventDay.save();

        return res.json({
            message: 'Attendance marked successfully',
            attendance
        });
    } catch (err: any) {
        console.error(err);
        return res.status(500).json({ message: 'Server error', error: err.message });
    }
};

// ==================== BULK MARK ATTENDANCE (HOTSPOT) ====================
export const bulkMarkAttendance = async (req: IEventDayRequest, res: Response) => {
    try {
        const { eventDayId } = req.params;
        const currentUserId = req.userId;
        const { userIds, checkInMethod = 'hotspot', latitude, longitude } = req.body;

        if (!userIds || !Array.isArray(userIds) || userIds.length === 0) {
            return res.status(400).json({ message: 'userIds array required' });
        }

        const eventDay = await EventDay.findById(eventDayId).populate('event');
        if (!eventDay) {
            return res.status(404).json({ message: 'Event day not found' });
        }

        const event = eventDay.event as any;
        const user = await User.findById(currentUserId);

        if (!user) {
            return res.status(404).json({ message: 'User not found' });
        }

        // Check if user can manage this event day
        const canManage = await canManageEventDay(user, event);
        if (!canManage) {
            return res.status(403).json({
                message: 'Only trainers, organizations, and admins from the same organization can mark attendance'
            });
        }

        const results = {
            marked: [] as string[],
            alreadyMarked: [] as string[],
            notParticipant: [] as string[]
        };

        for (const userId of userIds) {
            // Check if user is a participant
            const isParticipant = event.participants.some((p: any) => p.user.toString() === userId);
            if (!isParticipant) {
                results.notParticipant.push(userId);
                continue;
            }

            // Check if already marked
            const existingAttendance = eventDay.attendance.find((a: any) => a.user.toString() === userId);
            if (existingAttendance) {
                results.alreadyMarked.push(userId);
                continue;
            }

            // Create attendance record
            const attendance: any = {
                user: userId,
                checkInTime: new Date(),
                checkInMethod
            };

            // Add location if provided
            if (latitude && longitude) {
                attendance.checkInLocation = {
                    type: 'Point',
                    coordinates: [parseFloat(longitude), parseFloat(latitude)]
                };
            }

            eventDay.attendance.push(attendance);
            results.marked.push(userId);
        }

        await eventDay.save();

        return res.json({
            message: `Attendance marked for ${results.marked.length} user(s)`,
            results
        });
    } catch (err: any) {
        console.error(err);
        return res.status(500).json({ message: 'Server error', error: err.message });
    }
};

// ==================== UPDATE DAY METADATA ====================
export const updateDayMetadata = async (req: IEventDayRequest, res: Response) => {
    try {
        const { eventDayId } = req.params;
        const userId = req.userId;
        const {
            notes,
            weatherCondition,
            activitiesConducted,
            incidentsReported,
            equipmentUsed,
            isCompleted
        } = req.body;

        const eventDay = await EventDay.findById(eventDayId).populate('event');
        if (!eventDay) {
            return res.status(404).json({ message: 'Event day not found' });
        }

        const event = eventDay.event as any;
        const user = await User.findById(userId);

        if (!user) {
            return res.status(404).json({ message: 'User not found' });
        }

        // Check if user can manage this event day
        const canManage = await canManageEventDay(user, event);
        if (!canManage) {
            return res.status(403).json({
                message: 'Only trainers, organizations, and admins from the same organization can update day metadata'
            });
        }

        // Update fields
        if (notes !== undefined) eventDay.notes = notes;
        if (weatherCondition !== undefined) eventDay.weatherCondition = weatherCondition;
        if (activitiesConducted !== undefined) eventDay.activitiesConducted = activitiesConducted;
        if (incidentsReported !== undefined) eventDay.incidentsReported = incidentsReported;
        if (equipmentUsed !== undefined) eventDay.equipmentUsed = equipmentUsed;
        if (isCompleted !== undefined) eventDay.isCompleted = isCompleted;

        await eventDay.save();

        return res.json({
            message: 'Event day updated successfully',
            eventDay
        });
    } catch (err: any) {
        console.error(err);
        return res.status(500).json({ message: 'Server error', error: err.message });
    }
};

// ==================== GET ATTENDANCE REPORT ====================
export const getAttendanceReport = async (req: IEventDayRequest, res: Response) => {
    try {
        const { eventId } = req.params;
        const userId = req.userId;

        const event = await Event.findById(eventId).populate('participants.user', 'username email profilePhoto');
        if (!event) {
            return res.status(404).json({ message: 'Event not found' });
        }

        // Only event creator can view full attendance report
        if (event.createdBy.toString() !== userId) {
            return res.status(403).json({ message: 'Only event creator can view attendance report' });
        }

        const stats = await calculateAttendanceStats(eventId);
        const eventDays = await EventDay.find({ event: eventId })
            .sort({ dayNumber: 1 })
            .populate('attendance.user', 'username email profilePhoto');

        // Build participant-wise report
        const participantReport = event.participants.map(participant => {
            const user = participant.user as any;
            const attendanceDays = eventDays.filter(day =>
                day.attendance.some((a: any) => a.user._id.toString() === user._id.toString())
            );

            return {
                user: {
                    _id: user._id,
                    username: user.username,
                    email: user.email,
                    profilePhoto: user.profilePhoto
                },
                daysAttended: attendanceDays.length,
                totalDays: stats.totalDays,
                attendancePercentage: stats.totalDays > 0
                    ? Math.round((attendanceDays.length / stats.totalDays) * 100)
                    : 0,
                attendanceDates: attendanceDays.map(day => ({
                    date: day.date,
                    dayNumber: day.dayNumber,
                    checkInTime: day.attendance.find((a: any) => a.user._id.toString() === user._id.toString())?.checkInTime
                }))
            };
        });

        return res.json({
            event: {
                _id: event._id,
                title: event.title,
                code: event.code,
                startDate: event.startDate,
                endDate: event.endDate
            },
            stats,
            participantReport,
            dailyBreakdown: stats.dailyStats
        });
    } catch (err: any) {
        console.error(err);
        return res.status(500).json({ message: 'Server error', error: err.message });
    }
};

// ==================== START EVENT DAY ====================
export const startEventDay = async (req: IEventDayRequest, res: Response) => {
    try {
        const { eventDayId } = req.params;
        const userId = req.userId;

        const eventDay = await EventDay.findById(eventDayId).populate('event');
        if (!eventDay) {
            return res.status(404).json({ message: 'Event day not found' });
        }

        const event = eventDay.event as any;
        const user = await User.findById(userId);

        if (!user) {
            return res.status(404).json({ message: 'User not found' });
        }

        // Check if user can manage this event day
        const canManage = await canManageEventDay(user, event);
        if (!canManage) {
            return res.status(403).json({
                message: 'Only trainers, organizations, and admins from the same organization can start event day'
            });
        }

        // Check if event day date is today or in the past (can't start future events)
        const today = new Date();
        today.setHours(0, 0, 0, 0);
        const eventDate = new Date(eventDay.date);
        eventDate.setHours(0, 0, 0, 0);

        if (eventDate > today) {
            return res.status(400).json({
                message: 'Cannot start event day in the future. Event day can only be started on or after its scheduled date.'
            });
        }

        // Check if already started
        if (eventDay.hasStarted) {
            return res.status(400).json({ message: 'Event day already started' });
        }

        // Check if already completed
        if (eventDay.isCompleted) {
            return res.status(400).json({ message: 'Event day already completed' });
        }

        // Set as started
        eventDay.hasStarted = true;
        await eventDay.save();

        return res.json({
            message: 'Event day started successfully',
            eventDay: {
                _id: eventDay._id,
                date: eventDay.date,
                dayNumber: eventDay.dayNumber,
                hasStarted: eventDay.hasStarted,
                startTime: eventDay.startTime,
                endTime: eventDay.endTime
            }
        });
    } catch (err: any) {
        console.error(err);
        return res.status(500).json({ message: 'Server error', error: err.message });
    }
};

// ==================== END EVENT DAY ====================
export const endEventDay = async (req: IEventDayRequest, res: Response) => {
    try {
        const { eventDayId } = req.params;
        const userId = req.userId;

        const eventDay = await EventDay.findById(eventDayId).populate('event');
        if (!eventDay) {
            return res.status(404).json({ message: 'Event day not found' });
        }

        const event = eventDay.event as any;
        const user = await User.findById(userId);

        if (!user) {
            return res.status(404).json({ message: 'User not found' });
        }

        // Check if user can manage this event day
        const canManage = await canManageEventDay(user, event);
        if (!canManage) {
            return res.status(403).json({
                message: 'Only trainers, organizations, and admins from the same organization can end event day'
            });
        }

        // Check if started
        if (!eventDay.hasStarted) {
            return res.status(400).json({ message: 'Event day has not been started yet' });
        }

        // Check if already completed
        if (eventDay.isCompleted) {
            return res.status(400).json({ message: 'Event day already completed' });
        }

        // Validate completion requirements
        if (eventDay.photos.length === 0) {
            return res.status(400).json({
                message: 'Cannot end event day: No photos uploaded',
                requirement: 'photos'
            });
        }

        // if (eventDay.attendance.length === 0) {
        //     return res.status(400).json({
        //         message: 'Cannot end event day: No attendance recorded',
        //         requirement: 'attendance'
        //     });
        // }

        // Mark as completed
        eventDay.isCompleted = true;
        await eventDay.save();

        return res.json({
            message: 'Event day ended successfully',
            eventDay: {
                _id: eventDay._id,
                date: eventDay.date,
                dayNumber: eventDay.dayNumber,
                isCompleted: eventDay.isCompleted,
                completedAt: eventDay.completedAt,
                photoCount: eventDay.photos.length,
                attendanceCount: eventDay.attendance.length
            }
        });
    } catch (err: any) {
        console.error(err);
        return res.status(500).json({ message: 'Server error', error: err.message });
    }
};

// ==================== GET EVENT DAY STATUS ====================
export const getEventDayStatus = async (req: IEventDayRequest, res: Response) => {
    try {
        const { eventDayId } = req.params;

        const eventDay = await EventDay.findById(eventDayId);
        if (!eventDay) {
            return res.status(404).json({ message: 'Event day not found' });
        }

        const now = new Date();
        const eventEndTime = new Date(eventDay.endTime);

        let status: 'green' | 'red' | 'blue';
        let message: string;

        // Green: Completed with photos and attendance
        if (eventDay.isCompleted && eventDay.photos.length > 0 && eventDay.attendance.length > 0) {
            status = 'green';
            message = 'Event completed successfully';
        }
        // Red: Event day has passed but not completed properly
        else if (eventEndTime < now) {
            if (!eventDay.hasStarted) {
                status = 'red';
                message = 'Event was not conducted';
            } else if (eventDay.photos.length === 0) {
                status = 'red';
                message = 'Event missed: No photos uploaded';
            } else if (eventDay.attendance.length === 0) {
                status = 'red';
                message = 'Event missed: No attendance recorded';
            } else {
                status = 'red';
                message = 'Event not properly completed';
            }
        }
        // Blue: Future dates or planned but not yet conducted
        else {
            status = 'blue';
            message = eventDay.hasStarted ? 'Event in progress' : 'Event planned';
        }

        return res.json({
            status,
            message,
            eventDay: {
                _id: eventDay._id,
                date: eventDay.date,
                dayNumber: eventDay.dayNumber,
                startTime: eventDay.startTime,
                endTime: eventDay.endTime,
                hasStarted: eventDay.hasStarted,
                isCompleted: eventDay.isCompleted,
                photoCount: eventDay.photos.length,
                attendanceCount: eventDay.attendance.length
            }
        });
    } catch (err: any) {
        console.error(err);
        return res.status(500).json({ message: 'Server error', error: err.message });
    }
};