"use client"

import { motion } from "motion/react"
import { useEffect, useRef, useState, useSyncExternalStore } from "react"
import { ArrowUpIcon, PhoneIcon, PhoneOffIcon } from "lucide-react"
import { cn } from "@/lib/utils"
import type { DemoInfo } from "../demo-info"
import type { AiAccess } from "../demos"
import { BookingCard } from "./booking-card"
import { useAiChat } from "./use-ai-chat"

// Web Speech API: nicht in allen TS-DOM-Typen enthalten, daher minimal selbst beschrieben
type RecognitionEvent = { resultIndex: number; results: ArrayLike<{ isFinal: boolean; 0: { transcript: string } }> }
type Recognition = {
    lang: string
    interimResults: boolean
    continuous: boolean
    start(): void
    abort(): void
    onresult: ((event: RecognitionEvent) => void) | null
    onerror: ((event: { error: string }) => void) | null
    onend: (() => void) | null
}
type RecognitionCtor = new () => Recognition

function recognitionCtor(): RecognitionCtor | null {
    if (typeof window === "undefined") return null
    const speech = window as unknown as { SpeechRecognition?: RecognitionCtor; webkitSpeechRecognition?: RecognitionCtor }
    return speech.SpeechRecognition ?? speech.webkitSpeechRecognition ?? null
}

const subscribe = () => () => {}
const EXAMPLES = ["Haben Sie heute geöffnet?", "Ich möchte einen Termin vereinbaren", "Was kostet das bei Ihnen?"]

type CallState = "idle" | "speaking" | "listening" | "thinking" | "ended"

const statusLabel: Record<CallState, string> = {
    idle: "Bereit für Ihren Anruf",
    speaking: "Spricht …",
    listening: "Hört zu …",
    thinking: "Denkt nach …",
    ended: "Anruf beendet",
}

export function PhoneDemo({ access, info }: { access: AiAccess; info: DemoInfo }) {
    const [call, setCall] = useState<CallState>("idle")
    const [heard, setHeard] = useState("")
    const [draft, setDraft] = useState("")
    const [seconds, setSeconds] = useState(0)
    const [micError, setMicError] = useState<string | null>(null)
    const active = useRef(false)
    const voice = useRef<SpeechSynthesisVoice | null>(null)
    const recognition = useRef<Recognition | null>(null)
    const canListen = useSyncExternalStore(subscribe, () => recognitionCtor() !== null, () => true)
    const chat = useAiChat({ access, mode: "phone", onReply: speak, onError: () => listen() })
    const live = call !== "idle" && call !== "ended"

    useEffect(() => {
        const synth = typeof window !== "undefined" ? window.speechSynthesis : undefined
        const pick = () => {
            const german = (synth?.getVoices() ?? []).filter((v) => v.lang.toLowerCase().startsWith("de"))
            voice.current = german.find((v) => /google|anna|petra|helena|vicki|marlene|katja/i.test(v.name)) ?? german[0] ?? null
        }
        pick()
        synth?.addEventListener("voiceschanged", pick)
        return () => {
            synth?.removeEventListener("voiceschanged", pick)
            active.current = false
            recognition.current?.abort()
            synth?.cancel()
        }
    }, [])

    useEffect(() => {
        if (!live) return
        const timer = setInterval(() => setSeconds((s) => s + 1), 1000)
        return () => clearInterval(timer)
    }, [live])

    function speak(text: string) {
        if (!active.current) return
        const synth = window.speechSynthesis
        if (!text || !synth) return listen()

        synth.cancel()
        const utterance = new SpeechSynthesisUtterance(text)
        utterance.lang = "de-DE"
        utterance.rate = 1.04
        if (voice.current) utterance.voice = voice.current
        utterance.onend = () => listen()
        setCall("speaking")
        synth.speak(utterance)
    }

    function listen() {
        if (!active.current) return
        setHeard("")
        const Ctor = recognitionCtor()
        if (!Ctor || micError) {
            setCall("listening")
            return
        }

        const rec = new Ctor()
        rec.lang = "de-DE"
        rec.interimResults = true
        rec.continuous = false
        let finalText = ""
        let blocked = false

        rec.onresult = (event) => {
            let interim = ""
            for (let i = event.resultIndex; i < event.results.length; i++) {
                const result = event.results[i]
                if (result.isFinal) finalText += result[0].transcript
                else interim += result[0].transcript
            }
            setHeard(`${finalText} ${interim}`.trim())
        }
        rec.onerror = (event) => {
            if (event.error === "not-allowed" || event.error === "service-not-allowed") {
                blocked = true
                setMicError("Kein Mikrofonzugriff – bitte erlauben oder unten tippen.")
            }
        }
        rec.onend = () => {
            recognition.current = null
            if (!active.current) return
            if (finalText.trim()) {
                setHeard("")
                setCall("thinking")
                void chat.send(finalText)
            } else if (blocked) {
                setCall("listening")
            } else {
                listen()
            }
        }

        recognition.current = rec
        setCall("listening")
        rec.start()
    }

    function start() {
        active.current = true
        setSeconds(0)
        setMicError(null)
        chat.reset()
        speak(info.greeting)
    }

    function hangUp() {
        active.current = false
        recognition.current?.abort()
        window.speechSynthesis?.cancel()
        setCall("ended")
        setHeard("")
    }

    function sendText(text: string) {
        if (!text.trim() || chat.pending) return
        if (!active.current) {
            active.current = true
            setSeconds(0)
        }
        recognition.current?.abort()
        setDraft("")
        setCall("thinking")
        void chat.send(text)
    }

    const time = `${String(Math.floor(seconds / 60)).padStart(2, "0")}:${String(seconds % 60).padStart(2, "0")}`

    return (
        <div className="grid gap-6 lg:grid-cols-[minmax(0,400px)_minmax(0,1fr)]">
            <section className="flex flex-col items-center rounded-[2rem] border border-white/10 bg-white/[0.03] px-6 py-10 text-center">
                <p className="text-xs uppercase tracking-[0.25em] text-zinc-400">{live ? "Verbunden" : "KI-Telefon"}</p>
                <div className="relative mt-10 grid size-52 place-items-center">
                    {[0, 1, 2].map((ring) => (
                        <motion.span
                            key={ring}
                            className="absolute inset-0 rounded-full border border-t-accent"
                            animate={call === "speaking" ? { scale: [1, 1.45], opacity: [0.5, 0] } : { scale: 1, opacity: live ? 0.25 : 0.1 }}
                            transition={call === "speaking" ? { duration: 1.8, repeat: Infinity, delay: ring * 0.6, ease: "easeOut" } : { duration: 0.4 }}
                        />
                    ))}
                    <div className="relative grid size-36 place-items-center rounded-full bg-t-accent text-5xl font-semibold text-t-accent-fg shadow-[0_0_90px_-10px_var(--t-accent)]">
                        {info.brand.charAt(0).toUpperCase()}
                    </div>
                </div>
                <p className="mt-8 text-xl font-semibold">{info.assistantName}</p>
                <p className="text-sm text-zinc-400">{info.brand}</p>
                <p className="mt-4 flex h-6 items-center gap-2 text-sm text-t-accent">
                    {statusLabel[call]}
                    {live && <span className="font-mono text-zinc-400">{time}</span>}
                </p>
                <div className="mt-3 flex h-8 items-end gap-1" aria-hidden>
                    {call === "listening" &&
                        [0, 1, 2, 3, 4].map((bar) => (
                            <motion.span
                                key={bar}
                                className="w-1.5 rounded-full bg-t-accent"
                                animate={{ height: [8, 26, 12, 30, 8] }}
                                transition={{ duration: 1.1, repeat: Infinity, delay: bar * 0.12 }}
                            />
                        ))}
                </div>
                <div className="mt-6">
                    {live ? (
                        <button type="button" onClick={hangUp} aria-label="Auflegen" className="grid size-16 cursor-pointer place-items-center rounded-full bg-red-500 text-white transition-transform hover:scale-105">
                            <PhoneOffIcon className="size-6" />
                        </button>
                    ) : (
                        <button type="button" onClick={start} aria-label="Anrufen" className="relative grid size-16 cursor-pointer place-items-center rounded-full bg-emerald-500 text-white transition-transform hover:scale-105">
                            <span className="absolute inset-0 animate-ping rounded-full bg-emerald-500/40" />
                            <PhoneIcon className="relative size-6" />
                        </button>
                    )}
                </div>
                <p className="mt-6 max-w-xs text-xs text-zinc-500">
                    {micError ??
                        (canListen
                            ? "Nach dem Anrufen den Mikrofonzugriff erlauben und einfach sprechen. Ton einschalten!"
                            : "Dieser Browser kann keine Sprache erkennen – tippen Sie rechts (Chrome, Edge oder Safari empfohlen).")}
                </p>
            </section>

            <section className="flex min-h-[32rem] flex-col rounded-[2rem] border border-white/10 bg-white/[0.03]">
                <header className="border-b border-white/10 px-6 py-4 text-sm font-medium">Live-Mitschrift</header>
                <div className="flex-1 space-y-3 overflow-y-auto px-6 py-5">
                    {call === "idle" && chat.messages.length === 0 && (
                        <p className="text-sm text-zinc-500">Hier erscheint das Gespräch, sobald Sie anrufen oder eine Frage tippen.</p>
                    )}
                    {call !== "idle" && <Line role="assistant" text={info.greeting} />}
                    {chat.messages.map((message, i) =>
                        message.parts.map((part, j) =>
                            part.type === "booking" ? (
                                <BookingCard key={`${i}-${j}`} data={part.data} className="border-t-accent/40 bg-white/5" />
                            ) : (
                                <Line key={`${i}-${j}`} role={message.role} text={part.text} />
                            )
                        )
                    )}
                    {heard && <p className="text-sm italic text-zinc-400">„{heard} …“</p>}
                    {chat.error && <p className="text-sm text-red-400">{chat.error}</p>}
                </div>
                <div className="space-y-3 border-t border-white/10 p-4">
                    <div className="flex flex-wrap gap-2">
                        {EXAMPLES.map((example) => (
                            <button
                                key={example}
                                type="button"
                                onClick={() => sendText(example)}
                                className="cursor-pointer rounded-full border border-white/10 px-3 py-1.5 text-xs text-zinc-300 transition-colors hover:border-t-accent hover:text-white"
                            >
                                {example}
                            </button>
                        ))}
                    </div>
                    <form
                        className="flex gap-2"
                        onSubmit={(event) => {
                            event.preventDefault()
                            sendText(draft)
                        }}
                    >
                        <input
                            value={draft}
                            onChange={(event) => setDraft(event.target.value)}
                            placeholder="Oder hier tippen …"
                            aria-label="Nachricht an den Assistenten"
                            className="min-w-0 flex-1 rounded-full border border-white/10 bg-white/5 px-4 py-2.5 text-sm outline-none focus:border-t-accent"
                        />
                        <button type="submit" aria-label="Senden" disabled={!draft.trim() || chat.pending} className="grid size-10 shrink-0 cursor-pointer place-items-center rounded-full bg-t-accent text-t-accent-fg disabled:opacity-40">
                            <ArrowUpIcon className="size-4" />
                        </button>
                    </form>
                </div>
            </section>
        </div>
    )
}

function Line({ role, text }: { role: "user" | "assistant"; text: string }) {
    return (
        <div className={cn("flex", role === "user" && "justify-end")}>
            <p className={cn("max-w-[85%] rounded-2xl px-4 py-2.5 text-sm leading-relaxed", role === "user" ? "bg-t-accent text-t-accent-fg" : "bg-white/[0.06]")}>
                <span className="mb-0.5 block text-[10px] uppercase tracking-wider opacity-60">{role === "user" ? "Anrufer:in" : "Assistent"}</span>
                {text}
            </p>
        </div>
    )
}