"use client";

import { useEffect, useMemo, useState } from "react";
import { useRouter } from "next/navigation";
import { toast } from "sonner";
import { Card, CardContent, CardHeader, CardTitle } from "@/components/ui/card";
import { Button } from "@/components/ui/button";
import { Slider } from "@/components/ui/slider";
import { DeviceScanPanel } from "@/components/control/DeviceScanPanel";
import { DeviceRemapDialog } from "./DeviceRemapDialog";
import { disconnectAll, getButtplugClientHandle, getDevice, startScanning, stopScanning } from "@/lib/buttplug/client";
import { eventBuffer } from "@/lib/buttplug/event-buffer";
import { RecordingPlayer, type RecordingEventRow } from "@/lib/buttplug/player";
import { useButtplugStore } from "@/lib/buttplug/store";
import type { ActuatorInfo } from "@/lib/buttplug/types";
import type { RecordingDeviceSlot } from "@/lib/db/schema";
import { Pause, Play } from "lucide-react";

interface RecordingResponse {
  recording: {
    id: number;
    name: string;
    durationMs: number;
    deviceSlots: RecordingDeviceSlot[];
  };
  events: RecordingEventRow[];
}

function formatTime(ms: number): string {
  const totalSeconds = Math.floor(ms / 1000);
  return `${Math.floor(totalSeconds / 60)}:${(totalSeconds % 60).toString().padStart(2, "0")}`;
}

export function ReplayPlayer({ recordingId }: { recordingId: number }) {
  const router = useRouter();
  const scanning = useButtplugStore((s) => s.scanning);
  const devices = useButtplugStore((s) => s.devices);
  const setActuatorValue = useButtplugStore((s) => s.setActuatorValue);
  const removeDevice = useButtplugStore((s) => s.removeDevice);
  const connectedDevices = useMemo(() => Object.values(devices), [devices]);

  const [data, setData] = useState<RecordingResponse | null>(null);
  const [showRemap, setShowRemap] = useState(false);
  const [starting, setStarting] = useState(false);
  const [player, setPlayer] = useState<RecordingPlayer | null>(null);
  const [playing, setPlaying] = useState(false);
  const [elapsedMs, setElapsedMs] = useState(0);
  const [replayTargets, setReplayTargets] = useState<{ slotLabel: string; deviceName: string }[]>([]);
  const [replayDeviceIndexes, setReplayDeviceIndexes] = useState<number[]>([]);
  const [activeSessionId, setActiveSessionId] = useState<number | null>(null);

  useEffect(() => {
    fetch(`/api/recordings/${recordingId}`)
      .then((r) => r.json())
      .then(setData)
      .catch(() => toast.error("Could not load recording"));
  }, [recordingId]);

  useEffect(() => {
    return () => {
      void disconnectAll();
    };
  }, []);

  async function resetReplayDevices() {
    await Promise.all(
      replayDeviceIndexes.map(async (deviceIndex) => {
        const liveDevice = await getDevice(deviceIndex);
        await liveDevice?.stop().catch(() => {});
        devices[deviceIndex]?.actuators.forEach((a) => setActuatorValue(deviceIndex, a.featureIndex, 0));
      }),
    );
  }

  async function handleConfirmRemap(mapping: Map<number, number>) {
    if (!data) return;
    setShowRemap(false);
    setStarting(true);

    try {
      const orderedSlots = data.recording.deviceSlots.filter((s) => mapping.has(s.sourceSessionDeviceId));
      const targets = orderedSlots.map((slot) => {
        const deviceIndex = mapping.get(slot.sourceSessionDeviceId)!;
        const device = connectedDevices.find((d) => d.index === deviceIndex)!;
        return { slotLabel: slot.slotLabel, deviceName: device.displayName ?? device.name };
      });

      const body = {
        kind: "replay" as const,
        replayedRecordingId: data.recording.id,
        devices: orderedSlots.map((slot, i) => ({ slotLabel: slot.slotLabel, bleName: targets[i].deviceName })),
      };

      const res = await fetch("/api/play-sessions", {
        method: "POST",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify(body),
      });
      if (!res.ok) {
        toast.error("Could not start replay session");
        return;
      }
      const result: { session: { id: number; startedAt: number }; sessionDevices: { id: number }[] } =
        await res.json();

      eventBuffer.start(result.session.id, result.session.startedAt);
      const sessionDeviceIdToDeviceIndex = new Map<number, number>();
      orderedSlots.forEach((slot, i) => {
        const deviceIndex = mapping.get(slot.sourceSessionDeviceId)!;
        const newSessionDeviceId = result.sessionDevices[i]?.id;
        if (newSessionDeviceId !== undefined) {
          eventBuffer.registerSessionDevice(deviceIndex, newSessionDeviceId);
          sessionDeviceIdToDeviceIndex.set(slot.sourceSessionDeviceId, deviceIndex);
        }
      });

      const actuatorsByDeviceIndex = new Map<number, ActuatorInfo[]>(
        connectedDevices.map((d) => [d.index, d.actuators]),
      );

      // Reset every actuator on every device that will take part in this replay before
      // the first scheduled event fires, so playback always starts from a known-zero
      // state rather than whatever intensity was left over from manual control.
      const deviceIndexes = new Set(sessionDeviceIdToDeviceIndex.values());
      await Promise.all(
        [...deviceIndexes].map(async (deviceIndex) => {
          const liveDevice = await getDevice(deviceIndex);
          await liveDevice?.stop().catch(() => {});
          actuatorsByDeviceIndex.get(deviceIndex)?.forEach((a) => setActuatorValue(deviceIndex, a.featureIndex, 0));
        }),
      );

      const { runtime } = await getButtplugClientHandle();
      const instance = new RecordingPlayer({
        events: data.events,
        durationMs: data.recording.durationMs,
        sessionDeviceIdToDeviceIndex,
        actuatorsByDeviceIndex,
        runtime,
        onProgress: (elapsed) => setElapsedMs(elapsed),
        onError: (message) => toast.error(`Replay command failed: ${message}`),
        onComplete: async () => {
          setPlaying(false);
          eventBuffer.stop();
          await fetch(`/api/play-sessions/${result.session.id}`, {
            method: "PATCH",
            headers: { "Content-Type": "application/json" },
            body: JSON.stringify({ status: "completed" }),
          }).catch(() => {});
          toast.success("Replay finished");
        },
      });
      setReplayTargets(targets);
      setReplayDeviceIndexes([...deviceIndexes]);
      setActiveSessionId(result.session.id);
      setPlayer(instance);
      instance.play();
      setPlaying(true);
    } catch {
      toast.error("Could not start replay");
    } finally {
      setStarting(false);
    }
  }

  if (!data) {
    return <p className="text-sm text-muted-foreground">Loading recording...</p>;
  }

  return (
    <div className="flex flex-col gap-6">
      <Card className="bp-glass">
        <CardHeader>
          <CardTitle>{data.recording.name}</CardTitle>
        </CardHeader>
        <CardContent className="flex flex-col gap-4">
          {!player ? (
            <>
              <p className="text-sm text-muted-foreground">
                Connect the devices you want to replay onto, then match them to the recording&apos;s
                original device slots.
              </p>
              <div className="flex items-center gap-3">
                <DeviceScanPanel scanning={scanning} onScan={() => void startScanning()} onStopScan={() => void stopScanning()} />
                <Button
                  onClick={async () => {
                    try {
                      await getButtplugClientHandle();
                      setShowRemap(true);
                    } catch {
                      toast.error("Could not connect to Buttplug client");
                    }
                  }}
                  disabled={connectedDevices.length === 0 || starting}
                >
                  {starting ? "Starting..." : "Match devices & replay"}
                </Button>
              </div>
            </>
          ) : (
            <div className="flex flex-col gap-3">
              {replayTargets.length > 0 && (
                <div className="flex flex-wrap gap-2">
                  {replayTargets.map((t) => (
                    <span
                      key={t.slotLabel}
                      className="bp-readout rounded-md border border-border bg-card/60 px-2 py-1 text-xs text-muted-foreground"
                    >
                      {t.slotLabel} → {t.deviceName}
                    </span>
                  ))}
                </div>
              )}
              <Slider
                value={[elapsedMs]}
                max={data.recording.durationMs}
                onValueChange={([v]) => player.seek(v)}
              />
              <div className="flex items-center justify-between">
                <span className="bp-readout text-xs text-muted-foreground">
                  {formatTime(elapsedMs)} / {formatTime(data.recording.durationMs)}
                </span>
                <div className="flex items-center gap-2">
                  <Button
                    size="icon"
                    variant="outline"
                    onClick={async () => {
                      if (playing) {
                        player.pause();
                        setPlaying(false);
                      } else {
                        player.play();
                        setPlaying(true);
                      }
                      // Toggling either way leaves the toy holding whatever intensity was
                      // last sent - zero it out so pause always actually stops the device,
                      // and resume always starts from a clean, known state.
                      await resetReplayDevices();
                    }}
                    aria-label={playing ? "Pause" : "Play"}
                  >
                    {playing ? <Pause className="size-4" /> : <Play className="size-4" />}
                  </Button>
                  <Button
                    size="sm"
                    variant="ghost"
                    onClick={async () => {
                      player.stop();
                      setPlaying(false);
                      setElapsedMs(0);
                      eventBuffer.stop();
                      if (activeSessionId !== null) {
                        await fetch(`/api/play-sessions/${activeSessionId}`, {
                          method: "PATCH",
                          headers: { "Content-Type": "application/json" },
                          body: JSON.stringify({ status: "aborted" }),
                        }).catch(() => {});
                      }
                      // Fully disconnect every device that took part in this replay,
                      // not just stop the player - see handleDisconnectDevice in
                      // ButtplugConsole for why "stop + remove from store" is the
                      // closest equivalent Buttplug's protocol allows per-device.
                      await Promise.all(
                        replayDeviceIndexes.map(async (deviceIndex) => {
                          const liveDevice = await getDevice(deviceIndex);
                          await liveDevice?.stop().catch(() => {});
                          removeDevice(deviceIndex);
                        }),
                      );
                      setPlayer(null);
                      setReplayTargets([]);
                      setReplayDeviceIndexes([]);
                      setActiveSessionId(null);
                    }}
                  >
                    Stop
                  </Button>
                </div>
              </div>
            </div>
          )}
        </CardContent>
      </Card>

      <DeviceRemapDialog
        open={showRemap}
        deviceSlots={data.recording.deviceSlots}
        connectedDevices={connectedDevices}
        onCancel={() => setShowRemap(false)}
        onConfirm={(mapping) => void handleConfirmRemap(mapping)}
      />

      <Button variant="ghost" size="sm" onClick={() => router.push("/recordings")}>
        Back to recordings
      </Button>
    </div>
  );
}