import { useCallback, useEffect, useMemo, useRef, useState } from 'react';

import { MemberBadge } from '@renderer/components/team/MemberBadge';
import { UnreadCommentsBadge } from '@renderer/components/team/UnreadCommentsBadge';
import { Button } from '@renderer/components/ui/button';
import { Popover, PopoverContent, PopoverTrigger } from '@renderer/components/ui/popover';
import { Tooltip, TooltipContent, TooltipTrigger } from '@renderer/components/ui/tooltip';
import { useUnreadCommentCount } from '@renderer/hooks/useUnreadCommentCount';
import { useStore } from '@renderer/store';
import { REVIEW_STATE_DISPLAY, buildMemberColorMap } from '@renderer/utils/memberHelpers';
import {
  buildTaskChangePresenceKey,
  buildTaskChangeRequestOptions,
  isTaskSummaryCacheableForOptions,
} from '@renderer/utils/taskChangeRequest';
import { deriveTaskDisplayId, formatTaskDisplayLabel } from '@shared/utils/taskIdentity';
import {
  ArrowLeftFromLine,
  ArrowRightFromLine,
  CheckCircle2,
  FileCode,
  FilePenLine,
  GitPullRequestArrow,
  HelpCircle,
  Play,
  RotateCcw,
  Trash2,
  XCircle,
} from 'lucide-react';

import type { KanbanColumnId, KanbanTaskState, ResolvedTeamMember, TeamTask } from '@shared/types';

interface KanbanTaskCardProps {
  task: TeamTask;
  teamName: string;
  columnId: KanbanColumnId;
  kanbanTaskState?: KanbanTaskState;
  hasReviewers: boolean;
  compact?: boolean;
  taskMap: Map<string, TeamTask>;
  members: ResolvedTeamMember[];
  onRequestReview: (taskId: string) => void;
  onApprove: (taskId: string) => void;
  onRequestChanges: (taskId: string) => void;
  onMoveBackToDone: (taskId: string) => void;
  onStartTask: (taskId: string) => void;
  onCompleteTask: (taskId: string) => void;
  onCancelTask: (taskId: string) => void;
  onScrollToTask?: (taskId: string) => void;
  onTaskClick?: (task: TeamTask) => void;
  onViewChanges?: (taskId: string) => void;
  onDeleteTask?: (taskId: string) => void;
}

interface DependencyBadgeProps {
  taskId: string;
  taskMap: Map<string, TeamTask>;
  onScrollToTask?: (taskId: string) => void;
}

const DependencyBadge = ({
  taskId,
  taskMap,
  onScrollToTask,
}: DependencyBadgeProps): React.JSX.Element => {
  const depTask = taskMap.get(taskId);
  const isCompleted = depTask?.status === 'completed';

  return (
    <button
      type="button"
      className={`inline-flex items-center rounded px-1.5 py-0.5 text-[10px] font-medium transition-colors ${
        isCompleted
          ? 'bg-emerald-500/15 text-emerald-400 hover:bg-emerald-500/25'
          : 'bg-yellow-500/15 text-yellow-300 hover:bg-yellow-500/25'
      } ${onScrollToTask ? 'cursor-pointer' : ''}`}
      title={
        depTask
          ? `${formatTaskDisplayLabel(depTask)}: ${depTask.subject}`
          : `#${deriveTaskDisplayId(taskId)}`
      }
      onClick={(e) => {
        e.stopPropagation();
        onScrollToTask?.(taskId);
      }}
    >
      {depTask ? formatTaskDisplayLabel(depTask) : `#${deriveTaskDisplayId(taskId)}`}
    </button>
  );
};

const TruncatedTitle = ({
  text,
  className,
}: {
  text: string;
  className?: string;
}): React.JSX.Element => {
  const ref = useRef<HTMLHeadingElement>(null);
  const [isTruncated, setIsTruncated] = useState(false);

  const checkTruncation = useCallback(() => {
    const el = ref.current;
    if (el) {
      setIsTruncated(el.scrollWidth > el.clientWidth);
    }
  }, []);

  return (
    <Tooltip open={isTruncated ? undefined : false}>
      <TooltipTrigger asChild>
        <h5
          ref={ref}
          className={`truncate text-sm font-medium text-[var(--color-text)] ${className ?? ''}`}
          onMouseEnter={checkTruncation}
        >
          {text}
        </h5>
      </TooltipTrigger>
      <TooltipContent side="top" align="start">
        {text}
      </TooltipContent>
    </Tooltip>
  );
};

const CancelTaskButton = ({
  taskId,
  onConfirm,
}: {
  taskId: string;
  onConfirm: (taskId: string) => void;
}): React.JSX.Element => {
  const [open, setOpen] = useState(false);

  return (
    <Popover open={open} onOpenChange={setOpen}>
      <Tooltip>
        <TooltipTrigger asChild>
          <PopoverTrigger asChild>
            <Button
              variant="destructive"
              size="icon"
              className="size-8 rounded-full shadow-sm"
              aria-label={`Cancel task ${taskId}`}
              onClick={(e) => e.stopPropagation()}
            >
              <XCircle size={14} />
            </Button>
          </PopoverTrigger>
        </TooltipTrigger>
        <TooltipContent side="top">Cancel</TooltipContent>
      </Tooltip>
      <PopoverContent
        className="w-56 p-3"
        side="top"
        align="start"
        onClick={(e) => e.stopPropagation()}
      >
        <p className="mb-3 text-xs text-[var(--color-text-secondary)]">
          Move this task back to TODO and notify the team?
        </p>
        <div className="flex gap-2">
          <Button
            variant="destructive"
            size="sm"
            className="flex-1"
            onClick={() => {
              setOpen(false);
              onConfirm(taskId);
            }}
          >
            Confirm
          </Button>
          <Button variant="outline" size="sm" className="flex-1" onClick={() => setOpen(false)}>
            Keep
          </Button>
        </div>
      </PopoverContent>
    </Popover>
  );
};

interface TaskActionIconButtonProps {
  label: string;
  icon: React.ReactNode;
  onClick: (e: React.MouseEvent<HTMLButtonElement>) => void;
  className: string;
  variant?: 'outline' | 'ghost' | 'destructive';
}

const TaskActionIconButton = ({
  label,
  icon,
  onClick,
  className,
  variant = 'outline',
}: TaskActionIconButtonProps): React.JSX.Element => (
  <Tooltip>
    <TooltipTrigger asChild>
      <Button
        variant={variant}
        size="icon"
        className={`size-8 shrink-0 rounded-full shadow-sm ${className}`}
        aria-label={label}
        onClick={onClick}
      >
        {icon}
      </Button>
    </TooltipTrigger>
    <TooltipContent side="top">{label}</TooltipContent>
  </Tooltip>
);

export const KanbanTaskCard = ({
  task,
  teamName,
  columnId,
  kanbanTaskState: _kanbanTaskState,
  hasReviewers,
  compact,
  taskMap,
  members,
  onRequestReview,
  onApprove,
  onRequestChanges,
  onMoveBackToDone,
  onStartTask,
  onCompleteTask,
  onCancelTask,
  onScrollToTask,
  onTaskClick,
  onViewChanges,
  onDeleteTask,
}: KanbanTaskCardProps): React.JSX.Element => {
  const colorMap = useMemo(() => buildMemberColorMap(members), [members]);
  const unreadCount = useUnreadCommentCount(teamName, task.id, task.comments);
  const blockedByIds = task.blockedBy?.filter((id) => id.length > 0) ?? [];
  const blocksIds = task.blocks?.filter((id) => id.length > 0) ?? [];
  const hasBlockedBy = blockedByIds.length > 0;
  const hasBlocks = blocksIds.length > 0;

  // Lazy-check if task has file changes (only for done/review/approved columns)
  const showChangesColumn =
    (columnId === 'done' || columnId === 'review' || columnId === 'approved') && !!onViewChanges;
  const taskChangeRequestOptions = useMemo(() => buildTaskChangeRequestOptions(task), [task]);
  const useTerminalSummaryCache = useMemo(
    () => isTaskSummaryCacheableForOptions(taskChangeRequestOptions),
    [taskChangeRequestOptions]
  );
  const cacheKey = useMemo(
    () => buildTaskChangePresenceKey(teamName, task.id, taskChangeRequestOptions),
    [teamName, task.id, taskChangeRequestOptions]
  );
  const taskHasChanges = useStore((s) => s.taskHasChanges[cacheKey]);
  const checkTaskHasChanges = useStore((s) => s.checkTaskHasChanges);

  useEffect(() => {
    if (showChangesColumn && useTerminalSummaryCache && taskHasChanges !== true) {
      void checkTaskHasChanges(teamName, task.id, taskChangeRequestOptions);
    }
  }, [
    showChangesColumn,
    useTerminalSummaryCache,
    task.id,
    teamName,
    taskHasChanges,
    checkTaskHasChanges,
    taskChangeRequestOptions,
  ]);

  const isReviewManual = columnId === 'review' && !hasReviewers;
  const metaActions = (
    <>
      {showChangesColumn && taskHasChanges === true ? (
        <TaskActionIconButton
          label="Changes"
          icon={<FileCode className="size-3.5" />}
          variant="ghost"
          className="text-sky-400 hover:bg-sky-500/10 hover:text-sky-300"
          onClick={(e) => {
            e.stopPropagation();
            onViewChanges(task.id);
          }}
        />
      ) : null}
      <UnreadCommentsBadge unreadCount={unreadCount} totalCount={task.comments?.length ?? 0} />
      {onDeleteTask ? (
        <TaskActionIconButton
          label="Delete task"
          icon={<Trash2 size={14} />}
          variant="ghost"
          className="text-red-400 hover:bg-red-500/10 hover:text-red-300"
          onClick={(e) => {
            e.stopPropagation();
            onDeleteTask(task.id);
          }}
        />
      ) : null}
    </>
  );

  return (
    <div
      data-task-id={task.id}
      className={`relative cursor-pointer rounded-md border p-3 transition-colors hover:border-[var(--color-border-emphasis)] ${
        hasBlockedBy
          ? 'border-yellow-500/30 bg-[var(--color-surface-raised)]'
          : 'border-[var(--color-border)] bg-[var(--color-surface-raised)]'
      }`}
      role="button"
      tabIndex={0}
      onClick={() => onTaskClick?.(task)}
      onKeyDown={(e) => {
        if (e.key === 'Enter' || e.key === ' ') {
          e.preventDefault();
          onTaskClick?.(task);
        }
      }}
    >
      <span className="absolute left-[3px] top-[2px] text-[9px] leading-none text-[var(--color-text-muted)]">
        {formatTaskDisplayLabel(task)}
      </span>
      <div className="mb-2 pt-2">
        <div className="flex items-center gap-1">
          {task.owner ? <MemberBadge name={task.owner} color={colorMap.get(task.owner)} /> : null}
          {!compact && <TruncatedTitle text={task.subject} className="min-w-0" />}
        </div>
        {task.needsClarification ? (
          <span
            className={`mt-1 inline-flex items-center gap-1 rounded-full px-1.5 py-0.5 text-[10px] font-medium ${
              task.needsClarification === 'user'
                ? 'bg-red-500/15 text-red-400'
                : 'bg-blue-500/15 text-blue-600 dark:text-blue-400'
            }`}
          >
            <HelpCircle size={10} />
            {task.needsClarification === 'user' ? 'Awaiting user' : 'Awaiting lead'}
          </span>
        ) : null}
        {task.reviewState === 'needsFix' ? (
          <span
            className={`mt-1 inline-flex items-center rounded-full px-1.5 py-0.5 text-[10px] font-medium ${REVIEW_STATE_DISPLAY.needsFix.bg} ${REVIEW_STATE_DISPLAY.needsFix.text}`}
          >
            {REVIEW_STATE_DISPLAY.needsFix.label}
          </span>
        ) : null}
        {compact && <TruncatedTitle text={task.subject} className="mt-1" />}
      </div>

      {hasBlockedBy ? (
        <div className="mb-2 flex flex-wrap items-center gap-1">
          <span className="inline-flex items-center gap-0.5 text-[10px] text-yellow-300">
            <ArrowLeftFromLine size={10} />
            Blocked by
          </span>
          {blockedByIds.map((id) => (
            <DependencyBadge
              key={id}
              taskId={id}
              taskMap={taskMap}
              onScrollToTask={onScrollToTask}
            />
          ))}
        </div>
      ) : null}

      {hasBlocks ? (
        <div className="mb-2 flex flex-wrap items-center gap-1">
          <span className="inline-flex items-center gap-0.5 text-[10px] text-blue-600 dark:text-blue-400">
            <ArrowRightFromLine size={10} />
            Blocks
          </span>
          {blocksIds.map((id) => (
            <DependencyBadge
              key={id}
              taskId={id}
              taskMap={taskMap}
              onScrollToTask={onScrollToTask}
            />
          ))}
        </div>
      ) : null}

      <div className="flex items-center justify-between gap-2">
        <div className="flex min-w-0 flex-nowrap gap-2">
          {columnId === 'todo' ? (
            <>
              <TaskActionIconButton
                label="Start"
                icon={<Play size={14} />}
                className="border-emerald-500/40 text-emerald-400 hover:bg-emerald-500/10 hover:text-emerald-300"
                onClick={(e) => {
                  e.stopPropagation();
                  onStartTask(task.id);
                }}
              />
              <TaskActionIconButton
                label="Complete"
                icon={<CheckCircle2 size={14} />}
                className="border-emerald-500/40 text-emerald-400 hover:bg-emerald-500/10 hover:text-emerald-300"
                onClick={(e) => {
                  e.stopPropagation();
                  onCompleteTask(task.id);
                }}
              />
            </>
          ) : null}

          {columnId === 'in_progress' ? (
            <>
              <TaskActionIconButton
                label="Complete"
                icon={<CheckCircle2 size={14} />}
                className="border-emerald-500/40 text-emerald-400 hover:bg-emerald-500/10 hover:text-emerald-300"
                onClick={(e) => {
                  e.stopPropagation();
                  onCompleteTask(task.id);
                }}
              />
              <CancelTaskButton taskId={task.id} onConfirm={onCancelTask} />
            </>
          ) : null}

          {columnId === 'done' ? (
            <>
              <TaskActionIconButton
                label="Approve"
                icon={<CheckCircle2 size={14} />}
                className="border-emerald-500/40 text-emerald-400 hover:bg-emerald-500/10 hover:text-emerald-300"
                onClick={(e) => {
                  e.stopPropagation();
                  onApprove(task.id);
                }}
              />
              <TaskActionIconButton
                label="Request review"
                icon={<GitPullRequestArrow size={14} />}
                className="border-violet-500/40 text-violet-400 hover:bg-violet-500/10 hover:text-violet-300"
                onClick={(e) => {
                  e.stopPropagation();
                  onRequestReview(task.id);
                }}
              />
            </>
          ) : null}

          {columnId === 'review' ? (
            <div className="flex min-w-0 flex-1 items-center justify-between gap-2">
              {isReviewManual ? (
                <div className="min-w-0 shrink text-[11px] text-[var(--color-text-muted)]">
                  Manual review
                </div>
              ) : null}
              <div className="flex shrink-0 flex-nowrap gap-2">
                <TaskActionIconButton
                  label="Approve"
                  icon={<CheckCircle2 size={14} />}
                  className="border-emerald-500/40 text-emerald-400 hover:bg-emerald-500/10 hover:text-emerald-300"
                  onClick={(e) => {
                    e.stopPropagation();
                    onApprove(task.id);
                  }}
                />
                <TaskActionIconButton
                  label="Request changes"
                  icon={<FilePenLine size={14} />}
                  variant="destructive"
                  className="bg-red-500/90 text-white hover:bg-red-500"
                  onClick={(e) => {
                    e.stopPropagation();
                    onRequestChanges(task.id);
                  }}
                />
              </div>
              {isReviewManual ? (
                <div className="flex shrink-0 items-center gap-1.5">{metaActions}</div>
              ) : null}
            </div>
          ) : null}

          {columnId === 'approved' ? (
            <TaskActionIconButton
              label="Disapprove"
              icon={<RotateCcw size={14} />}
              className="border-amber-500/40 text-amber-400 hover:bg-amber-500/10 hover:text-amber-300"
              onClick={(e) => {
                e.stopPropagation();
                onMoveBackToDone(task.id);
              }}
            />
          ) : null}
        </div>

        {!isReviewManual ? (
          <div className="flex shrink-0 flex-nowrap items-center gap-1.5">{metaActions}</div>
        ) : null}
      </div>
    </div>
  );
};