"use client";

import { v4 as uuidv4 } from "uuid";
import { useState, useEffect, useRef } from "react";
import { Button } from "@/components/ui/button";
import { Card, CardContent } from "@/components/ui/card";
import { ArrowLeft, GitBranch, Terminal, Clock } from "lucide-react";
import { Tabs, TabsContent, TabsList, TabsTrigger } from "@/components/ui/tabs";
import { ThreadSwitcher } from "./thread-switcher";
import { ThreadMetadata } from "./types";
import { useStream } from "@langchain/langgraph-sdk/react";
import { ManagerGraphState } from "@open-swe/shared/open-swe/manager/types";
import { PlannerGraphState } from "@open-swe/shared/open-swe/planner/types";
import { GraphState } from "@open-swe/shared/open-swe/types";
import { ActionsRenderer } from "./actions-renderer";
import { ThemeToggle } from "../theme-toggle";
import { HumanMessage } from "@langchain/core/messages";
import {
  DO_NOT_RENDER_ID_PREFIX,
  PROGRAMMER_GRAPH_ID,
  PLANNER_GRAPH_ID,
} from "@open-swe/shared/constants";
import { useThreadStatus } from "@/hooks/useThreadStatus";
import { cn } from "@/lib/utils";

import { StickToBottom } from "use-stick-to-bottom";
import {
  StickyToBottomContent,
  ScrollToBottom,
} from "../../utils/scroll-utils";
import { ManagerChat } from "./manager-chat";
import { CancelStreamButton } from "./cancel-stream-button";

interface ThreadViewProps {
  stream: ReturnType<typeof useStream<ManagerGraphState>>;
  displayThread: ThreadMetadata;
  allDisplayThreads: ThreadMetadata[];
  onBackToHome: () => void;
}

export function ThreadView({
  stream,
  displayThread,
  allDisplayThreads,
  onBackToHome,
}: ThreadViewProps) {
  const [chatInput, setChatInput] = useState("");
  const [selectedTab, setSelectedTab] = useState<"planner" | "programmer">(
    "planner",
  );
  const [plannerSession, setPlannerSession] =
    useState<ManagerGraphState["plannerSession"]>();
  const [programmerSession, setProgrammerSession] =
    useState<ManagerGraphState["programmerSession"]>();
  const [errorMessage, setErrorMessage] = useState("");

  useEffect(() => {
    if (
      stream?.values?.plannerSession &&
      plannerSession?.runId !== stream.values.plannerSession.runId
    ) {
      // State shouldn't update before we use it below, but still create a copy to avoid race conditions
      const prevPlannerSession = plannerSession;
      setPlannerSession(stream.values.plannerSession);

      if (prevPlannerSession && selectedTab === "programmer") {
        // If we already has a planner session, and the user is currently on the programmer tab, bring them back to the planner tab
        setSelectedTab("planner");
      }
    }
  }, [stream?.values]);

  useEffect(() => {
    if (stream.error) {
      const errorMessage =
        typeof stream.error === "object" && "message" in stream.error
          ? (stream.error.message as string)
          : "An unknown error occurred in the manager";
      setErrorMessage(errorMessage);
    } else {
      setErrorMessage("");
    }
  }, [stream.error]);

  const { status: realTimeStatus } = useThreadStatus(displayThread.id);

  const getStatusDotColor = (status: string) => {
    switch (status) {
      case "running":
        return "bg-blue-500 dark:bg-blue-400";
      case "completed":
        return "bg-green-500 dark:bg-green-400";
      case "paused":
        return "bg-yellow-500 dark:bg-yellow-400";
      case "error":
        return "bg-red-500 dark:bg-red-400";
      default:
        return "bg-gray-500 dark:bg-gray-400";
    }
  };

  const plannerCancelRef = useRef<(() => void) | null>(null);
  const programmerCancelRef = useRef<(() => void) | null>(null);

  const cancelRun = () => {
    // TODO: ideally this calls stream.client.runs.cancel(threadId, runId)
    stream.stop();
  };

  const handleSendMessage = () => {
    if (chatInput.trim()) {
      const newHumanMessage = new HumanMessage({
        id: uuidv4(),
        content: chatInput,
      });
      stream.submit(
        {
          messages: [newHumanMessage],
        },
        {
          streamResumable: true,
          optimisticValues: (prev) => ({
            ...prev,
            messages: [...(prev.messages ?? []), newHumanMessage],
          }),
        },
      );
      setChatInput("");
    }
  };

  const filteredMessages = stream.messages.filter((message) => {
    return !message.id?.startsWith(DO_NOT_RENDER_ID_PREFIX);
  });

  return (
    <div className="bg-background flex h-screen flex-1 flex-col">
      {/* Header */}
      <div className="border-border bg-card absolute top-0 right-0 left-0 z-10 border-b px-4 py-2">
        <div className="flex items-center gap-3">
          <Button
            variant="ghost"
            size="sm"
            className="text-muted-foreground hover:bg-muted hover:text-foreground h-6 w-6 p-0"
            onClick={onBackToHome}
          >
            <ArrowLeft className="h-3 w-3" />
          </Button>
          <div className="flex min-w-0 flex-1 items-center gap-2">
            <div
              className={cn(
                "size-2 flex-shrink-0 rounded-full",
                getStatusDotColor(realTimeStatus),
              )}
            ></div>
            <span className="text-muted-foreground max-w-[500px] truncate font-mono text-sm">
              {displayThread.title}
            </span>
            {displayThread.repository && (
              <>
                <span className="text-muted-foreground text-xs">•</span>
                <GitBranch className="text-muted-foreground h-3 w-3" />
                <span className="text-muted-foreground truncate text-xs">
                  {displayThread.repository}
                </span>
              </>
            )}
          </div>
          <ThreadSwitcher
            currentThread={displayThread}
            allThreads={allDisplayThreads}
          />
          <ThemeToggle />
        </div>
      </div>

      {/* Main Content - Split Layout */}
      <div className="flex h-full w-full pt-12">
        <ManagerChat
          messages={filteredMessages}
          chatInput={chatInput}
          setChatInput={setChatInput}
          handleSendMessage={handleSendMessage}
          isLoading={stream.isLoading}
          cancelRun={cancelRun}
          errorMessage={errorMessage}
        />
        {/* Right Side - Actions & Plan */}
        <div className="flex h-full flex-1 flex-col">
          <div className="relative flex-1">
            <StickToBottom
              className="absolute inset-0"
              initial={true}
            >
              <StickyToBottomContent
                className="h-full overflow-y-auto"
                contentClassName="space-y-4 p-4"
                content={
                  <Tabs
                    defaultValue="planner"
                    className="w-full"
                    value={selectedTab}
                    onValueChange={(value) =>
                      setSelectedTab(value as "planner" | "programmer")
                    }
                  >
                    <div className="flex items-center justify-between">
                      <TabsList className="bg-muted/70 dark:bg-gray-800">
                        <TabsTrigger value="planner">Planner</TabsTrigger>
                        <TabsTrigger value="programmer">Programmer</TabsTrigger>
                      </TabsList>

                      <div className="flex gap-2">
                        {selectedTab === "planner" &&
                          plannerCancelRef.current && (
                            <CancelStreamButton
                              stream={stream}
                              threadId={plannerSession?.threadId}
                              runId={plannerSession?.runId}
                              streamName="Planner"
                            />
                          )}

                        {selectedTab === "programmer" &&
                          programmerCancelRef.current && (
                            <CancelStreamButton
                              stream={stream}
                              threadId={programmerSession?.threadId}
                              runId={programmerSession?.runId}
                              streamName="Programmer"
                            />
                          )}
                      </div>
                    </div>

                    <TabsContent value="planner">
                      <Card className="border-border bg-card px-0 py-4 dark:bg-gray-950">
                        <CardContent className="space-y-2 p-3 pt-0">
                          {plannerSession && (
                            <ActionsRenderer<PlannerGraphState>
                              graphId={PLANNER_GRAPH_ID}
                              threadId={plannerSession.threadId}
                              runId={plannerSession.runId}
                              setProgrammerSession={setProgrammerSession}
                              programmerSession={programmerSession}
                              setSelectedTab={setSelectedTab}
                              onStreamReady={(cancelFn) => {
                                if (cancelFn) {
                                  plannerCancelRef.current = cancelFn;
                                } else {
                                  plannerCancelRef.current = null;
                                }
                              }}
                            />
                          )}
                          {!plannerSession && (
                            <div className="flex items-center justify-center gap-2 py-8">
                              <Clock className="text-muted-foreground size-4" />
                              <span className="text-muted-foreground text-sm">
                                No planner session
                              </span>
                            </div>
                          )}
                        </CardContent>
                      </Card>
                    </TabsContent>
                    <TabsContent value="programmer">
                      <Card className="border-border bg-card px-0 py-4 dark:bg-gray-950">
                        <CardContent className="space-y-2 p-3 pt-0">
                          {programmerSession && (
                            <ActionsRenderer<GraphState>
                              graphId={PROGRAMMER_GRAPH_ID}
                              threadId={programmerSession.threadId}
                              runId={programmerSession.runId}
                              onStreamReady={(cancelFn) => {
                                if (cancelFn) {
                                  programmerCancelRef.current = cancelFn;
                                } else {
                                  programmerCancelRef.current = null;
                                }
                              }}
                            />
                          )}
                          {!programmerSession && (
                            <div className="flex items-center justify-center gap-2 py-8">
                              <Terminal className="text-muted-foreground size-4" />
                              <span className="text-muted-foreground text-sm">
                                No programmer session
                              </span>
                            </div>
                          )}
                        </CardContent>
                      </Card>
                    </TabsContent>
                  </Tabs>
                }
                footer={
                  <div className="absolute bottom-4 left-1/2 -translate-x-1/2">
                    <ScrollToBottom className="animate-in fade-in-0 zoom-in-95" />
                  </div>
                }
              />
            </StickToBottom>
          </div>
        </div>
      </div>
    </div>
  );
}