import { useMemo, useState } from 'react';

import { Badge } from '@renderer/components/ui/badge';
import { Button } from '@renderer/components/ui/button';
import { Checkbox } from '@renderer/components/ui/checkbox';
import {
  Dialog,
  DialogContent,
  DialogDescription,
  DialogFooter,
  DialogHeader,
  DialogTitle,
} from '@renderer/components/ui/dialog';
import { Input } from '@renderer/components/ui/input';
import { Label } from '@renderer/components/ui/label';
import { MentionableTextarea } from '@renderer/components/ui/MentionableTextarea';
import {
  Select,
  SelectContent,
  SelectItem,
  SelectTrigger,
  SelectValue,
} from '@renderer/components/ui/select';
import { getTeamColorSet } from '@renderer/constants/teamColors';
import { useDraftPersistence } from '@renderer/hooks/useDraftPersistence';
import { formatAgentRole } from '@renderer/utils/formatAgentRole';
import { buildMemberColorMap } from '@renderer/utils/memberHelpers';
import { AlertTriangle, Search } from 'lucide-react';

import type { MentionSuggestion } from '@renderer/types/mention';
import type { ResolvedTeamMember, TeamTaskWithKanban } from '@shared/types';

interface CreateTaskDialogProps {
  open: boolean;
  teamName: string;
  members: ResolvedTeamMember[];
  tasks: TeamTaskWithKanban[];
  isTeamAlive?: boolean;
  defaultSubject?: string;
  defaultDescription?: string;
  defaultOwner?: string;
  defaultStartImmediately?: boolean;
  onClose: () => void;
  onSubmit: (
    subject: string,
    description: string,
    owner?: string,
    blockedBy?: string[],
    related?: string[],
    prompt?: string,
    startImmediately?: boolean
  ) => void;
  submitting?: boolean;
}

export const CreateTaskDialog = ({
  open,
  teamName,
  members,
  tasks,
  isTeamAlive = false,
  defaultSubject = '',
  defaultDescription = '',
  defaultOwner = '',
  defaultStartImmediately,
  onClose,
  onSubmit,
  submitting = false,
}: CreateTaskDialogProps): React.JSX.Element => {
  const colorMap = useMemo(() => buildMemberColorMap(members), [members]);
  const [subject, setSubject] = useState(defaultSubject);
  const descriptionDraft = useDraftPersistence({
    key: `createTask:${teamName}:description`,
    initialValue: defaultDescription || undefined,
  });
  const [owner, setOwner] = useState<string>(defaultOwner);
  const [blockedBy, setBlockedBy] = useState<string[]>([]);
  const [related, setRelated] = useState<string[]>([]);
  const [startImmediately, setStartImmediately] = useState(true);
  const promptDraft = useDraftPersistence({ key: `createTask:${teamName}:prompt` });
  const [blockedBySearch, setBlockedBySearch] = useState('');
  const [relatedSearch, setRelatedSearch] = useState('');
  const [prevOpen, setPrevOpen] = useState(false);

  if (open && !prevOpen) {
    setSubject(defaultSubject);
    if (defaultDescription) {
      descriptionDraft.setValue(defaultDescription);
    }
    setOwner(defaultOwner);
    setBlockedBy([]);
    setRelated([]);
    setStartImmediately(defaultStartImmediately ?? isTeamAlive);
    promptDraft.clearDraft();
    setBlockedBySearch('');
    setRelatedSearch('');
  }
  if (open !== prevOpen) {
    setPrevOpen(open);
  }

  const mentionSuggestions = useMemo<MentionSuggestion[]>(
    () =>
      members.map((m) => ({
        id: m.name,
        name: m.name,
        subtitle: formatAgentRole(m.role) ?? formatAgentRole(m.agentType) ?? undefined,
        color: colorMap.get(m.name),
      })),
    [members, colorMap]
  );

  const requiresOwner = defaultStartImmediately === true;
  const canSubmit = subject.trim().length > 0 && !submitting && (!requiresOwner || !!owner);

  // Only show non-internal, non-deleted tasks as candidates for blocking
  const availableTasks = tasks.filter(
    (t) => t.status !== 'deleted' && t.kanbanColumn !== 'approved'
  );

  const toggleBlockedBy = (taskId: string): void => {
    setBlockedBy((prev) =>
      prev.includes(taskId) ? prev.filter((id) => id !== taskId) : [...prev, taskId]
    );
  };

  const toggleRelated = (taskId: string): void => {
    setRelated((prev) =>
      prev.includes(taskId) ? prev.filter((id) => id !== taskId) : [...prev, taskId]
    );
  };

  const handleSubmit = (): void => {
    if (!canSubmit) return;
    onSubmit(
      subject.trim(),
      descriptionDraft.value.trim(),
      owner || undefined,
      blockedBy.length > 0 ? blockedBy : undefined,
      related.length > 0 ? related : undefined,
      promptDraft.value.trim() || undefined,
      startImmediately
    );
    descriptionDraft.clearDraft();
    promptDraft.clearDraft();
  };

  const handleOpenChange = (nextOpen: boolean): void => {
    if (!nextOpen) {
      onClose();
    }
  };

  const assigneeField = (
    <div className="grid gap-2">
      <Label className={requiresOwner ? undefined : 'label-optional'}>
        {requiresOwner ? 'Assignee' : 'Assignee (optional)'}
      </Label>
      <Select
        value={owner || '__unassigned__'}
        onValueChange={(v) => setOwner(v === '__unassigned__' ? '' : v)}
      >
        <SelectTrigger>
          <SelectValue placeholder={requiresOwner ? 'Select a member' : 'Unassigned'} />
        </SelectTrigger>
        <SelectContent>
          {!requiresOwner && <SelectItem value="__unassigned__">Unassigned</SelectItem>}
          {members.map((m) => {
            const role = formatAgentRole(m.role) ?? formatAgentRole(m.agentType);
            const resolvedColor = colorMap.get(m.name);
            const memberColor = resolvedColor ? getTeamColorSet(resolvedColor) : null;
            return (
              <SelectItem key={m.name} value={m.name}>
                <span className="inline-flex items-center gap-1.5">
                  {memberColor ? (
                    <span
                      className="inline-block size-2 shrink-0 rounded-full"
                      style={{ backgroundColor: memberColor.border }}
                    />
                  ) : null}
                  <span style={memberColor ? { color: memberColor.text } : undefined}>
                    {m.name}
                  </span>
                  {role ? <span className="text-[var(--color-text-muted)]">({role})</span> : null}
                </span>
              </SelectItem>
            );
          })}
        </SelectContent>
      </Select>
    </div>
  );

  return (
    <Dialog open={open} onOpenChange={handleOpenChange}>
      <DialogContent className="sm:max-w-[480px]">
        <DialogHeader>
          <DialogTitle>Create Task</DialogTitle>
          <DialogDescription>
            The task will be created in the team&apos;s tasks/ directory and appear on the Kanban
            board.
          </DialogDescription>
        </DialogHeader>

        {!isTeamAlive ? (
          <div className="flex items-start gap-2 rounded-md border border-amber-500/30 bg-amber-500/10 px-3 py-2">
            <AlertTriangle size={14} className="mt-0.5 shrink-0 text-amber-400" />
            <p className="text-xs leading-relaxed text-amber-300">
              Team is offline. The task will be added to <strong>TODO</strong> &mdash; launch the
              team to start execution.
            </p>
          </div>
        ) : null}

        <div className="grid gap-4 py-2">
          <div className="grid gap-2">
            <Label htmlFor="task-subject">Subject</Label>
            <Input
              id="task-subject"
              placeholder="What needs to be done?"
              value={subject}
              autoFocus
              onChange={(e) => setSubject(e.target.value)}
              onKeyDown={(e) => {
                if (e.key === 'Enter' && canSubmit) handleSubmit();
              }}
            />
          </div>

          {assigneeField}

          <div className="grid gap-2">
            <Label htmlFor="task-description" className="label-optional">
              Description (optional)
            </Label>
            <MentionableTextarea
              id="task-description"
              placeholder="Task details..."
              value={descriptionDraft.value}
              onValueChange={descriptionDraft.setValue}
              suggestions={mentionSuggestions}
              minRows={3}
              maxRows={12}
              footerRight={
                descriptionDraft.isSaved ? (
                  <span className="text-[10px] text-[var(--color-text-muted)]">Draft saved</span>
                ) : null
              }
            />
          </div>

          <div className="grid gap-2">
            <Label htmlFor="task-prompt" className="label-optional">
              Prompt for assignee (optional)
            </Label>
            <MentionableTextarea
              id="task-prompt"
              placeholder="Custom instructions for the team member..."
              value={promptDraft.value}
              onValueChange={promptDraft.setValue}
              suggestions={mentionSuggestions}
              minRows={3}
              maxRows={12}
              footerRight={
                promptDraft.isSaved ? (
                  <span className="text-[10px] text-[var(--color-text-muted)]">Draft saved</span>
                ) : null
              }
            />
          </div>

          {owner ? (
            <div className="grid gap-1">
              <div className="flex items-center gap-2">
                <Checkbox
                  id="task-start-immediately"
                  checked={isTeamAlive ? startImmediately : false}
                  onCheckedChange={(v) => setStartImmediately(v === true)}
                  disabled={!isTeamAlive}
                />
                <Label
                  htmlFor="task-start-immediately"
                  className={`text-xs font-normal ${!isTeamAlive ? 'text-[var(--color-text-muted)]' : ''}`}
                >
                  Start immediately
                </Label>
              </div>
              {!isTeamAlive ? (
                <p className="text-[10px] text-[var(--color-text-muted)]">
                  Team is offline. Launch the team first to start tasks immediately.
                </p>
              ) : null}
            </div>
          ) : null}

          {availableTasks.length > 0 ? (
            <div className="grid gap-2">
              <Label className="label-optional">Blocked by tasks (optional)</Label>
              <div className="overflow-hidden rounded-md border border-[var(--color-border)] bg-[var(--color-surface)]">
                {availableTasks.length > 3 ? (
                  <div className="relative border-b border-[var(--color-border)] px-2 py-1.5">
                    <Search
                      size={12}
                      className="absolute left-3 top-1/2 -translate-y-1/2 text-[var(--color-text-muted)]"
                    />
                    <input
                      type="text"
                      placeholder="Search tasks..."
                      value={blockedBySearch}
                      onChange={(e) => setBlockedBySearch(e.target.value)}
                      className="w-full bg-transparent py-0.5 pl-5 text-xs text-[var(--color-text)] placeholder:text-[var(--color-text-muted)] focus:outline-none"
                    />
                  </div>
                ) : null}
                <div className="max-h-[108px] overflow-y-auto p-1.5">
                  {availableTasks
                    .filter(
                      (t) =>
                        !blockedBySearch ||
                        t.subject.toLowerCase().includes(blockedBySearch.toLowerCase()) ||
                        t.id.includes(blockedBySearch)
                    )
                    .map((t) => {
                      const isSelected = blockedBy.includes(t.id);
                      return (
                        <button
                          key={t.id}
                          type="button"
                          className={`flex w-full items-center gap-2 rounded px-2 py-1.5 text-left text-xs transition-colors ${
                            isSelected
                              ? 'bg-blue-500/15 text-blue-300'
                              : 'text-[var(--color-text-secondary)] hover:bg-[var(--color-surface-raised)]'
                          }`}
                          onClick={() => toggleBlockedBy(t.id)}
                        >
                          <span
                            className={`flex size-3.5 shrink-0 items-center justify-center rounded-sm border text-[9px] ${
                              isSelected
                                ? 'border-blue-400 bg-blue-500/30 text-blue-300'
                                : 'border-[var(--color-border-emphasis)]'
                            }`}
                          >
                            {isSelected ? '\u2713' : ''}
                          </span>
                          <Badge
                            variant="secondary"
                            className="shrink-0 px-1 py-0 text-[10px] font-normal"
                          >
                            #{t.id}
                          </Badge>
                          <span className="truncate">{t.subject}</span>
                        </button>
                      );
                    })}
                </div>
              </div>
              {blockedBy.length > 0 ? (
                <p className="text-[11px] text-yellow-300">
                  Task will be blocked by: {blockedBy.map((id) => `#${id}`).join(', ')}
                </p>
              ) : null}
            </div>
          ) : null}

          {availableTasks.length > 0 ? (
            <div className="grid gap-2">
              <Label className="label-optional">Related tasks (optional)</Label>
              <div className="overflow-hidden rounded-md border border-[var(--color-border)] bg-[var(--color-surface)]">
                {availableTasks.length > 3 ? (
                  <div className="relative border-b border-[var(--color-border)] px-2 py-1.5">
                    <Search
                      size={12}
                      className="absolute left-3 top-1/2 -translate-y-1/2 text-[var(--color-text-muted)]"
                    />
                    <input
                      type="text"
                      placeholder="Search tasks..."
                      value={relatedSearch}
                      onChange={(e) => setRelatedSearch(e.target.value)}
                      className="w-full bg-transparent py-0.5 pl-5 text-xs text-[var(--color-text)] placeholder:text-[var(--color-text-muted)] focus:outline-none"
                    />
                  </div>
                ) : null}
                <div className="max-h-[108px] overflow-y-auto p-1.5">
                  {availableTasks
                    .filter(
                      (t) =>
                        !relatedSearch ||
                        t.subject.toLowerCase().includes(relatedSearch.toLowerCase()) ||
                        t.id.includes(relatedSearch)
                    )
                    .map((t) => {
                      const isSelected = related.includes(t.id);
                      return (
                        <button
                          key={`related:${t.id}`}
                          type="button"
                          className={`flex w-full items-center gap-2 rounded px-2 py-1.5 text-left text-xs transition-colors ${
                            isSelected
                              ? 'bg-purple-500/15 text-purple-300'
                              : 'text-[var(--color-text-secondary)] hover:bg-[var(--color-surface-raised)]'
                          }`}
                          onClick={() => toggleRelated(t.id)}
                        >
                          <span
                            className={`flex size-3.5 shrink-0 items-center justify-center rounded-sm border text-[9px] ${
                              isSelected
                                ? 'border-purple-400 bg-purple-500/30 text-purple-300'
                                : 'border-[var(--color-border-emphasis)]'
                            }`}
                          >
                            {isSelected ? '\u2713' : ''}
                          </span>
                          <Badge
                            variant="secondary"
                            className="shrink-0 px-1 py-0 text-[10px] font-normal"
                          >
                            #{t.id}
                          </Badge>
                          <span className="truncate">{t.subject}</span>
                        </button>
                      );
                    })}
                </div>
              </div>
              {related.length > 0 ? (
                <p className="text-[11px] text-purple-300">
                  Related: {related.map((id) => `#${id}`).join(', ')}
                </p>
              ) : null}
            </div>
          ) : null}
        </div>

        <DialogFooter>
          <Button variant="outline" size="sm" onClick={onClose} disabled={submitting}>
            Cancel
          </Button>
          <Button size="sm" onClick={handleSubmit} disabled={!canSubmit}>
            {submitting ? 'Creating...' : 'Create'}
          </Button>
        </DialogFooter>
      </DialogContent>
    </Dialog>
  );
};