import React, { memo, useMemo, useState, useRef, useEffect } from 'react';
import { useAppSelector } from '@/hooks/useAppSelector';
import { ITaskListGroup } from '@/types/tasks/taskList.types';
import TaskCard from './TaskCard';
import { themeWiseColor } from '@/utils/themeWiseColor';
import EnhancedKanbanCreateTaskCard from '../EnhancedKanbanCreateTaskCard';
import { useTranslation } from 'react-i18next';
import { useAuthService } from '@/hooks/useAuth';
import useIsProjectManager from '@/hooks/useIsProjectManager';
import { useAppDispatch } from '@/hooks/useAppDispatch';
import { ITaskStatusUpdateModel } from '@/types/tasks/task-status-update-model.types';
import { statusApiService } from '@/api/taskAttributes/status/status.api.service';
import { fetchStatuses } from '@/features/taskAttributes/taskStatusSlice';
import logger from '@/utils/errorLogger';
import { evt_project_board_column_setting_click } from '@/shared/worklenz-analytics-events';
import { phasesApiService } from '@/api/taskAttributes/phases/phases.api.service';
import { ITaskPhase } from '@/types/tasks/taskPhase.types';
import { useMixpanelTracking } from '@/hooks/useMixpanelTracking';
import {
    deleteStatusToggleDrawer,
    seletedStatusCategory,
} from '@/features/projects/status/DeleteStatusSlice';
import {
    fetchEnhancedKanbanGroups,
    IGroupBy,
} from '@/features/enhanced-kanban/enhanced-kanban.slice';


interface KanbanGroupProps {
    group: ITaskListGroup;
    onGroupDragStart: (e: React.DragEvent, groupId: string) => void;
    onGroupDragOver: (e: React.DragEvent) => void;
    onGroupDrop: (e: React.DragEvent, groupId: string) => void;
    onTaskDragStart: (e: React.DragEvent, taskId: string, groupId: string) => void;
    onTaskDragOver: (e: React.DragEvent, groupId: string, taskIdx: number | null) => void;
    onTaskDrop: (e: React.DragEvent, groupId: string, taskIdx: number | null) => void;
    onDragEnd: (e: React.DragEvent) => void;
    hoveredTaskIdx: number | null;
    hoveredGroupId: string | null;
}

const KanbanGroup: React.FC<KanbanGroupProps> = memo(({
    group,
    onGroupDragStart,
    onGroupDragOver,
    onGroupDrop,
    onTaskDragStart,
    onTaskDragOver,
    onTaskDrop,
    onDragEnd,
    hoveredTaskIdx,
    hoveredGroupId
}) => {
    const [isHover, setIsHover] = useState<boolean>(false);
    const isOwnerOrAdmin = useAuthService().isOwnerOrAdmin();
    const [isEditable, setIsEditable] = useState(false);
    const isProjectManager = useIsProjectManager();
    const [isLoading, setIsLoading] = useState(false);
    const [name, setName] = useState(group.name);
    const inputRef = useRef<HTMLInputElement>(null);
    const [editName, setEdit] = useState(group.name);
    const [isEllipsisActive, setIsEllipsisActive] = useState(false);
    const [showDropdown, setShowDropdown] = useState(false);
    const [showDeleteConfirm, setShowDeleteConfirm] = useState(false);
    const dropdownRef = useRef<HTMLDivElement>(null);
    const themeMode = useAppSelector(state => state.themeReducer.mode);
    const dispatch = useAppDispatch();
    const { projectId } = useAppSelector(state => state.projectReducer);
    const { groupBy } = useAppSelector(state => state.enhancedKanbanReducer);
    const { statusCategories, status } = useAppSelector(state => state.taskStatusReducer);
    const { trackMixpanelEvent } = useMixpanelTracking();
    const [showNewCardTop, setShowNewCardTop] = useState(false);
    const [showNewCardBottom, setShowNewCardBottom] = useState(false);
    const { t } = useTranslation('kanban-board');

    const headerBackgroundColor = useMemo(() => {
        if (themeMode === 'dark') {
            return group.color_code_dark || group.color_code || '#1e1e1e';
        }
        return group.color_code || '#f5f5f5';
    }, [themeMode, group.color_code, group.color_code_dark]);

    const getUniqueSectionName = (baseName: string): string => {
        // Check if the base name already exists
        const existingNames = status.map(status => status.name?.toLowerCase());

        if (!existingNames.includes(baseName.toLowerCase())) {
            return baseName;
        }

        // If the base name exists, add a number suffix
        let counter = 1;
        let newName = `${baseName.trim()} (${counter})`;

        while (existingNames.includes(newName.toLowerCase())) {
            counter++;
            newName = `${baseName.trim()} (${counter})`;
        }

        return newName;
    };

    const updateStatus = async (category = group.category_id ?? null) => {
        if (!category || !projectId || !group.id) return;
        const sectionName = getUniqueSectionName(name);
        const body: ITaskStatusUpdateModel = {
            name: sectionName,
            project_id: projectId,
            category_id: category,
        };
        const res = await statusApiService.updateStatus(group.id, body, projectId);
        if (res.done) {
            dispatch(fetchEnhancedKanbanGroups(projectId));
            dispatch(fetchStatuses(projectId));
            setName(sectionName);
        } else {
            setName(editName);
            logger.error('Error updating status', res.message);
        }
    };

    const handleChange = async (e: React.ChangeEvent<HTMLInputElement>) => {
        const taskName = e.target.value;
        setName(taskName);
    };

    const handleBlur = async () => {
        setIsEditable(false);
        if (name === editName) return;
        if (name === t('untitledSection')) {
            dispatch(fetchEnhancedKanbanGroups(projectId ?? ''));
        }

        if (!projectId || !group.id) return;

        if (groupBy === IGroupBy.STATUS) {
            await updateStatus();
        }

        if (groupBy === IGroupBy.PHASE) {
            const body = {
                id: group.id,
                name: name,
            };

            const res = await phasesApiService.updateNameOfPhase(
                group.id,
                body as ITaskPhase,
                projectId
            );
            if (res.done) {
                trackMixpanelEvent(evt_project_board_column_setting_click, { Rename: 'Phase' });
                dispatch(fetchEnhancedKanbanGroups(projectId));
            }
        }
    };

    const handlePressEnter = (e: React.KeyboardEvent<HTMLInputElement>) => {
        if (e.key === 'Enter') {
            setShowNewCardTop(true);
            setShowNewCardBottom(false);
            handleBlur();
        }
    };

    const handleDeleteSection = async () => {
        if (!projectId || !group.id) return;

        try {
            if (groupBy === IGroupBy.STATUS) {
                const replacingStatusId = '';
                const res = await statusApiService.deleteStatus(group.id, projectId, replacingStatusId);
                if (res.message === 'At least one status should exists under each category.') return;
                if (res.done) {
                    dispatch(fetchEnhancedKanbanGroups(projectId));
                } else {
                    dispatch(
                        seletedStatusCategory({
                            id: group.id,
                            name: name,
                            category_id: group.category_id ?? '',
                            message: res.message ?? '',
                        })
                    );
                    dispatch(deleteStatusToggleDrawer());
                }
            } else if (groupBy === IGroupBy.PHASE) {
                const res = await phasesApiService.deletePhaseOption(group.id, projectId);
                if (res.done) {
                    dispatch(fetchEnhancedKanbanGroups(projectId));
                }
            }
        } catch (error) {
            logger.error('Error deleting section', error);
        }
    };

    const handleRename = () => {
        setIsEditable(true);
        setShowDropdown(false);
        setTimeout(() => {
            if (inputRef.current) {
                inputRef.current.focus();
                inputRef.current.select(); // Select all text on focus
            }
        }, 100);
    };

    const handleCategoryChange = (categoryId: string) => {
        updateStatus(categoryId);
        setShowDropdown(false);
    };

    const handleDelete = () => {
        setShowDeleteConfirm(true);
        setShowDropdown(false);
    };

    // Close dropdown when clicking outside
    useEffect(() => {
        const handleClickOutside = (event: MouseEvent) => {
            if (dropdownRef.current && !dropdownRef.current.contains(event.target as Node)) {
                setShowDropdown(false);
            }
        };

        if (showDropdown) {
            document.addEventListener('mousedown', handleClickOutside);
        }

        return () => {
            document.removeEventListener('mousedown', handleClickOutside);
        };
    }, [showDropdown]);

    return (
        <div className="enhanced-kanban-group" style={{ position: 'relative' }}
        >
            {/* Background layer - z-index 0 */}
            <div
                className="enhanced-kanban-group-background"
                style={{
                    position: 'absolute',
                    top: 0,
                    left: 0,
                    width: '100%',
                    height: '100%',
                    border: `0.1px solid ${themeMode === 'dark' ? '#404040' : '#e0e0e0'}`,
                    borderRadius: '8px',
                    zIndex: 0
                }}
                onDragOver={e => { e.preventDefault(); onTaskDragOver(e, group.id, null); }}
                onDrop={e => { e.preventDefault(); onTaskDrop(e, group.id, null); }}
            />

            {/* Content layer - z-index 1 */}
            <div style={{ position: 'relative', zIndex: 1 }}>
                <div
                    className="enhanced-kanban-group-header"
                    style={{
                        backgroundColor: headerBackgroundColor,
                    }}
                    draggable
                    onDragStart={e => onGroupDragStart(e, group.id)}
                    onDragOver={onGroupDragOver}
                    onDrop={e => onGroupDrop(e, group.id)}
                    onDragEnd={onDragEnd}
                >
                    <div
                        className="flex items-center justify-between w-full font-semibold rounded-md"
                        onMouseEnter={() => setIsHover(true)}
                        onMouseLeave={() => setIsHover(false)}
                    >
                        <div
                            className="flex items-center gap-2 cursor-pointer"
                            onClick={e => {
                                e.stopPropagation();
                                if ((isProjectManager || isOwnerOrAdmin) && group.name !== t('unmapped'))
                                    setIsEditable(true);
                            }}
                            onMouseDown={e => {
                                e.stopPropagation();
                            }}
                        >
                            {isLoading && (
                                <div className="w-4 h-4 border-2 border-gray-300 border-t-blue-600 rounded-full animate-spin"></div>
                            )}
                            {isEditable ? (
                                <input
                                    ref={inputRef}
                                    value={name}
                                    className={`bg-transparent border-none outline-none text-sm font-semibold capitalize min-w-[185px] ${themeMode === 'dark' ? 'text-gray-800' : 'text-gray-900'
                                        }`}
                                    onChange={handleChange}
                                    onBlur={handleBlur}
                                    onKeyDown={handlePressEnter}
                                    onMouseDown={e => {
                                        e.stopPropagation();
                                    }}
                                    onClick={e => {
                                        e.stopPropagation();
                                    }}
                                />
                            ) : (
                                <div
                                    className={`min-w-[185px] text-sm font-semibold capitalize truncate ${themeMode === 'dark' ? 'text-gray-800' : 'text-gray-900'
                                        }`}
                                    title={isEllipsisActive ? name : undefined}
                                    onMouseDown={e => {
                                        e.stopPropagation();
                                        e.preventDefault();
                                    }}
                                    onMouseUp={e => {
                                        e.stopPropagation();
                                    }}
                                    onClick={e => {
                                        e.stopPropagation();
                                    }}
                                >
                                    {name} ({group.tasks.length})
                                </div>
                            )}
                        </div>

                        <div className="flex items-center gap-1">
                            <button
                                type="button"
                                className="w-7 h-7 flex items-center justify-center rounded-full hover:bg-black/10 transition-colors"
                                onClick={() => {
                                    setShowNewCardTop(true);
                                    setShowNewCardBottom(false);
                                }}
                            >
                                <svg className="w-4 h-4 text-gray-800" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                                    <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M12 4v16m8-8H4" />
                                </svg>
                            </button>

                            {(isOwnerOrAdmin || isProjectManager) && name !== t('unmapped') && (
                                <div className="relative" ref={dropdownRef}>
                                    <button
                                        type="button"
                                        className="w-7 h-7 flex items-center justify-center rounded-full hover:bg-black/10 transition-colors"
                                        onClick={() => setShowDropdown(!showDropdown)}
                                    >
                                        <svg className="w-4 h-4 text-gray-800 rotate-90" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                                            <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M12 5v.01M12 12v.01M12 19v.01M12 6a1 1 0 110-2 1 1 0 010 2zm0 7a1 1 0 110-2 1 1 0 010 2zm0 7a1 1 0 110-2 1 1 0 010 2z" />
                                        </svg>
                                    </button>

                                    {showDropdown && (
                                        <div className="absolute right-0 top-full mt-1 w-48 bg-white dark:bg-gray-800 rounded-md shadow-lg border border-gray-200 dark:border-gray-700 z-50">
                                            <div className="py-1">
                                                <button
                                                    type="button"
                                                    className="w-full px-4 py-2 text-left text-sm hover:bg-gray-100 dark:hover:bg-gray-700 flex items-center gap-2"
                                                    onClick={handleRename}
                                                >
                                                    <svg className="w-4 h-4" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                                                        <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M11 5H6a2 2 0 00-2 2v11a2 2 0 002 2h11a2 2 0 002-2v-5m-1.414-9.414a2 2 0 112.828 2.828L11.828 15H9v-2.828l8.586-8.586z" />
                                                    </svg>
                                                    {t('rename')}
                                                </button>

                                                {groupBy === IGroupBy.STATUS && statusCategories && (
                                                    <div className="border-t border-gray-200 dark:border-gray-700">
                                                        <div className="px-4 py-2 text-xs font-medium text-gray-500 uppercase tracking-wide">
                                                            {t('changeCategory')}
                                                        </div>
                                                        {statusCategories.map(status => (
                                                            <button
                                                                key={status.id}
                                                                type="button"
                                                                className="w-full px-4 py-2 text-left text-sm hover:bg-gray-100 dark:hover:bg-gray-700 flex items-center gap-2"
                                                                onClick={() => status.id && handleCategoryChange(status.id)}
                                                            >
                                                                <div
                                                                    className="w-3 h-3 rounded-full"
                                                                    style={{ backgroundColor: status.color_code }}
                                                                ></div>
                                                                <span className={group.category_id === status.id ? 'font-bold' : ''}>
                                                                    {status.name}
                                                                </span>
                                                            </button>
                                                        ))}
                                                    </div>
                                                )}

                                                {groupBy !== IGroupBy.PRIORITY && (
                                                    <div className="border-t border-gray-200 dark:border-gray-700">
                                                        <button
                                                            type="button"
                                                            className="w-full px-4 py-2 text-left text-sm hover:bg-gray-100 dark:hover:bg-gray-700 flex items-center gap-2 text-red-600 dark:text-red-400"
                                                            onClick={e => {
                                                                e.stopPropagation();
                                                                handleDelete();
                                                            }}
                                                        >
                                                            <svg className="w-4 h-4" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                                                                <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M19 7l-.867 12.142A2 2 0 0116.138 21H7.862a2 2 0 01-1.995-1.858L5 7m5 4v6m4-6v6m1-10V4a1 1 0 00-1-1h-4a1 1 0 00-1 1v3M4 7h16" />
                                                            </svg>
                                                            {t('delete')}
                                                        </button>
                                                    </div>
                                                )}
                                            </div>
                                        </div>
                                    )}
                                </div>
                            )}
                        </div>
                    </div>
                </div>

                {/* Simple Delete Confirmation */}
                {showDeleteConfirm && (
                    <div className="fixed inset-0 bg-black bg-opacity-25 flex items-center justify-center z-50">
                        <div className="bg-white dark:bg-gray-800 rounded-lg shadow-lg border border-gray-200 dark:border-gray-700 max-w-sm w-full mx-4">
                            <div className="p-4">
                                <div className="flex items-center gap-3 mb-3">
                                    <div className="flex-shrink-0">
                                        <svg className="w-5 h-5 text-orange-500" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                                            <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M12 9v2m0 4h.01m-6.938 4h13.856c1.54 0 2.502-1.667 1.732-2.5L13.732 4c-.77-.833-1.964-.833-2.732 0L3.732 16.5c-.77.833.192 2.5 1.732 2.5z" />
                                        </svg>
                                    </div>
                                    <div>
                                        <h3 className={`text-base font-medium ${themeMode === 'dark' ? 'text-white' : 'text-gray-900'}`}>
                                            {t('deleteConfirmationTitle')}
                                        </h3>
                                    </div>
                                </div>
                                <div className="flex justify-end gap-2">
                                    <button
                                        type="button"
                                        className={`px-3 py-1.5 text-sm font-medium rounded border transition-colors ${themeMode === 'dark'
                                            ? 'border-gray-600 text-gray-300 hover:bg-gray-600'
                                            : 'border-gray-300 text-gray-700 hover:bg-gray-50'
                                            }`}
                                        onClick={() => setShowDeleteConfirm(false)}
                                    >
                                        {t('deleteConfirmationCancel')}
                                    </button>
                                    <button
                                        type="button"
                                        className="px-3 py-1.5 text-sm font-medium text-white bg-red-600 border border-transparent rounded hover:bg-red-700 transition-colors"
                                        onClick={() => {
                                            handleDeleteSection();
                                            setShowDeleteConfirm(false);
                                        }}
                                    >
                                        {t('deleteConfirmationOk')}
                                    </button>
                                </div>
                            </div>
                        </div>
                    </div>
                )}
                <div className="enhanced-kanban-group-tasks">
                    {/* Create card at top */}
                    {showNewCardTop && (
                        <EnhancedKanbanCreateTaskCard
                            sectionId={group.id}
                            setShowNewCard={setShowNewCardTop}
                            position="top"
                        />
                    )}

                    {/* If group is empty, render a drop zone */}
                    {group.tasks.length === 0 && !showNewCardTop && !showNewCardBottom && (
                        <div
                            className="empty-drop-zone"
                            style={{
                                padding: 8,
                                height: 500,
                                background: themeWiseColor(
                                    'linear-gradient( 180deg, #fafafa, rgba(245, 243, 243, 0))',
                                    'linear-gradient( 180deg, #2a2b2d, rgba(42, 43, 45, 0))',
                                    themeMode
                                ),
                                borderRadius: 6,
                                display: 'flex',
                                flexDirection: 'column',
                                alignItems: 'center',
                                justifyContent: 'flex-start',
                                paddingTop: 8,
                                color: '#888',
                                fontStyle: 'italic',
                            }}
                            onDragOver={e => { e.preventDefault(); onTaskDragOver(e, group.id, 0); }}
                            onDrop={e => { e.preventDefault(); onTaskDrop(e, group.id, 0); }}
                        >
                            {/* Drop indicator at the end of the group */}
                            {hoveredGroupId === group.id && hoveredTaskIdx === group.tasks.length && (
                                <div className="drop-preview-indicator">
                                    <div className="drop-line" />
                                </div>
                            )}
                            {(isOwnerOrAdmin || isProjectManager) && !showNewCardTop && !showNewCardBottom && (
                                <button
                                    type="button"
                                    className="h-10 w-full rounded-md border-2 border-dashed border-gray-300 dark:border-gray-600 hover:border-gray-400 dark:hover:border-gray-500 transition-colors flex items-center justify-center gap-2 text-gray-500 hover:text-gray-700 dark:text-gray-400 dark:hover:text-gray-300"
                                    onClick={() => {
                                        setShowNewCardBottom(false);
                                        setShowNewCardTop(true);
                                    }}
                                >
                                    <svg className="w-4 h-4" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                                        <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M12 4v16m8-8H4" />
                                    </svg>
                                    {t('addTask')}
                                </button>
                            )}
                        </div>
                    )
                    }


                    {/* Drop indicator at the top of the group */}
                    {hoveredGroupId === group.id && hoveredTaskIdx === 0 && (
                        <div className="drop-preview-indicator">
                            <div className="drop-line" />
                        </div>
                    )}

                    {group.tasks.map((task, idx) => (
                        <React.Fragment key={task.id}>
                            {/* Drop indicator before this card */}
                            {hoveredGroupId === group.id && hoveredTaskIdx === idx && (
                                <div
                                    onDragOver={e => onTaskDragOver(e, group.id, idx)}
                                    onDrop={e => onTaskDrop(e, group.id, idx)}
                                >
                                    <div className="w-full h-full bg-red-500" style={{
                                        height: 80,
                                        background: themeMode === 'dark' ? '#2a2a2a' : '#E2EAF4',
                                        borderRadius: 6,
                                        border: `5px`
                                    }}></div>
                                </div>
                            )}
                            <TaskCard
                                task={task}
                                onTaskDragStart={onTaskDragStart}
                                onTaskDragOver={onTaskDragOver}
                                onTaskDrop={onTaskDrop}
                                groupId={group.id}
                                idx={idx}
                                onDragEnd={onDragEnd}
                            />
                        </React.Fragment>
                    ))}
                    {/* Drop indicator at the end of the group */}
                    {hoveredGroupId === group.id && hoveredTaskIdx === group.tasks.length && (
                        <div
                        onDragOver={e => onTaskDragOver(e, group.id, group.tasks.length)}
                        onDrop={e => onTaskDrop(e, group.id, group.tasks.length)}
                    >
                        <div className="w-full h-full bg-red-500" style={{
                            height: 80,
                            background: themeMode === 'dark' ? '#2a2a2a' : '#E2EAF4',
                            borderRadius: 6,
                            border: `5px`
                        }}></div>
                    </div>
                    )}

                    {/* Create card at bottom */}
                    {showNewCardBottom && (
                        <EnhancedKanbanCreateTaskCard
                            sectionId={group.id}
                            setShowNewCard={setShowNewCardBottom}
                            position="bottom"
                        />
                    )}

                    {/* Footer Add Task Button */}
                    {!showNewCardTop && !showNewCardBottom && group.tasks.length > 0 && (
                        <button
                            type="button"
                            className="h-10 w-full rounded-md border-2 border-dashed border-gray-300 dark:border-gray-600 hover:border-gray-400 dark:hover:border-gray-500 transition-colors flex items-center justify-center gap-2 text-gray-500 hover:text-gray-700 dark:text-gray-400 dark:hover:text-gray-300 mt-2"
                            onClick={() => {
                                setShowNewCardBottom(true);
                                setShowNewCardTop(false);
                            }}
                        >
                            <svg className="w-4 h-4" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                                <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M12 4v16m8-8H4" />
                            </svg>
                            {t('addTask')}
                        </button>
                    )}

                    {/* Drop indicator at the end of the group */}
                    {hoveredGroupId === group.id && hoveredTaskIdx === group.tasks.length && (
                        <div className="drop-preview-indicator">
                            <div className="drop-line" />
                        </div>
                    )}
                </div>
            </div>
        </div>
    );
});

KanbanGroup.displayName = 'KanbanGroup';

export default KanbanGroup; 