"use client";

import { useEffect, useRef, useState } from "react";
import { formatDistanceToNow } from "date-fns";
import { BargeInInput } from "@/components/mission-control/BargeInInput";
import { Badge } from "@/components/ui/badge";
import type { BadgeVariant } from "@/components/ui/badge";
import { Button } from "@/components/ui/button";
import { Card, CardContent, CardHeader, CardTitle } from "@/components/ui/card";
import { PanelControls } from "@/components/mission-control/PanelControls";
import { ScrollArea } from "@/components/ui/scroll-area";
import {
  useSessionStream,
  useSessions,
  type MissionControlConnectionStatus,
  type MissionControlMessageRole,
} from "@/hooks/useMissionControl";

const ROLE_BADGE_VARIANT: Record<MissionControlMessageRole, BadgeVariant> = {
  user: "badge-blue",
  assistant: "status-success",
  tool: "badge-amber",
  system: "badge-muted",
};

const CONNECTION_DOT_CLASS: Record<MissionControlConnectionStatus, string> = {
  connected: "bg-emerald-500",
  connecting: "bg-amber-500",
  error: "bg-red-500",
};

const CONNECTION_TEXT: Record<MissionControlConnectionStatus, string> = {
  connected: "Connected",
  connecting: "Connecting",
  error: "Error",
};

export interface OrchestratorPanelProps {
  sessionId?: string;
  onClose?: () => void;
  closeDisabled?: boolean;
  onExpand?: () => void;
  expanded?: boolean;
}

interface PanelHeaderActionsProps {
  onClose?: () => void;
  closeDisabled?: boolean;
  onExpand?: () => void;
  expanded?: boolean;
}

function PanelHeaderActions({
  onClose,
  closeDisabled = false,
  onExpand,
  expanded = false,
}: PanelHeaderActionsProps): React.JSX.Element | null {
  if (!onClose && !onExpand) {
    return null;
  }

  return (
    <div className="flex items-center gap-1">
      {onExpand ? (
        <Button
          type="button"
          variant="ghost"
          size="icon"
          className="h-7 w-7"
          onClick={onExpand}
          aria-label={expanded ? "Collapse panel" : "Expand panel"}
          title={expanded ? "Collapse panel" : "Expand panel"}
        >
          <span aria-hidden="true" className="text-base leading-none">
            {expanded ? "↙" : "↗"}
          </span>
        </Button>
      ) : null}
      {onClose ? (
        <Button
          type="button"
          variant="ghost"
          size="icon"
          className="h-7 w-7"
          onClick={onClose}
          disabled={closeDisabled}
          aria-label="Remove panel"
          title="Remove panel"
        >
          <span aria-hidden="true" className="text-base leading-none">
            ×
          </span>
        </Button>
      ) : null}
    </div>
  );
}

function formatRelativeTimestamp(timestamp: string): string {
  const parsedDate = new Date(timestamp);
  if (Number.isNaN(parsedDate.getTime())) {
    return "just now";
  }

  return formatDistanceToNow(parsedDate, { addSuffix: true });
}

export function OrchestratorPanel({
  sessionId,
  onClose,
  closeDisabled,
  onExpand,
  expanded,
}: OrchestratorPanelProps): React.JSX.Element {
  const { messages, status, error } = useSessionStream(sessionId ?? "");
  const { sessions } = useSessions();
  const bottomAnchorRef = useRef<HTMLDivElement | null>(null);
  const [optimisticStatus, setOptimisticStatus] = useState<string | null>(null);

  const selectedSessionStatus = sessions.find((session) => session.id === sessionId)?.status;
  const controlsStatus = optimisticStatus ?? selectedSessionStatus ?? "unknown";
  const panelHeaderActionProps = {
    ...(onClose !== undefined ? { onClose } : {}),
    ...(closeDisabled !== undefined ? { closeDisabled } : {}),
    ...(onExpand !== undefined ? { onExpand } : {}),
    ...(expanded !== undefined ? { expanded } : {}),
  };

  useEffect(() => {
    bottomAnchorRef.current?.scrollIntoView({ block: "end" });
  }, [messages.length]);

  useEffect(() => {
    setOptimisticStatus(null);
  }, [sessionId, selectedSessionStatus]);

  if (!sessionId) {
    return (
      <Card className="flex h-full min-h-[220px] flex-col">
        <CardHeader>
          <div className="flex items-start justify-between gap-2">
            <CardTitle className="text-base">Orchestrator Panel</CardTitle>
            <PanelHeaderActions {...panelHeaderActionProps} />
          </div>
        </CardHeader>
        <CardContent className="flex flex-1 items-center justify-center text-sm text-muted-foreground">
          Select an agent to view its stream
        </CardContent>
      </Card>
    );
  }

  return (
    <Card className="flex h-full min-h-[220px] flex-col">
      <CardHeader className="space-y-2">
        <div className="flex items-start justify-between gap-2">
          <CardTitle className="text-base">Orchestrator Panel</CardTitle>
          <PanelHeaderActions {...panelHeaderActionProps} />
        </div>
        <div className="flex flex-col gap-2 sm:flex-row sm:items-start sm:justify-between">
          <div className="flex items-center gap-2 text-xs text-muted-foreground">
            <span
              className={`h-2.5 w-2.5 rounded-full ${CONNECTION_DOT_CLASS[status]} ${
                status === "connecting" ? "animate-pulse" : ""
              }`}
              aria-hidden="true"
            />
            <span>{CONNECTION_TEXT[status]}</span>
          </div>
          <PanelControls
            sessionId={sessionId}
            status={controlsStatus}
            onStatusChange={setOptimisticStatus}
          />
        </div>
        <p className="truncate text-xs text-muted-foreground">Session: {sessionId}</p>
      </CardHeader>
      <CardContent className="flex min-h-0 flex-1 flex-col p-0">
        <div className="min-h-0 flex-1">
          <ScrollArea className="h-full w-full">
            <div className="flex min-h-full flex-col gap-3 p-4">
              {messages.length === 0 ? (
                <p className="mt-6 text-center text-sm text-muted-foreground">
                  {error ?? "Waiting for messages..."}
                </p>
              ) : (
                messages.map((message) => (
                  <article
                    key={message.id}
                    className="rounded-lg border border-border/70 bg-card px-3 py-2"
                  >
                    <div className="mb-2 flex items-center justify-between gap-2">
                      <Badge variant={ROLE_BADGE_VARIANT[message.role]} className="uppercase">
                        {message.role}
                      </Badge>
                      <time className="text-xs text-muted-foreground">
                        {formatRelativeTimestamp(message.timestamp)}
                      </time>
                    </div>
                    <p className="whitespace-pre-wrap break-words text-sm text-foreground">
                      {message.content}
                    </p>
                  </article>
                ))
              )}
              <div ref={bottomAnchorRef} />
            </div>
          </ScrollArea>
        </div>
        <div className="border-t border-border/70 p-3">
          <BargeInInput sessionId={sessionId} />
        </div>
      </CardContent>
    </Card>
  );
}