import React, { useCallback, useEffect, useMemo, useRef, useState } from "react";
import { motion, useReducedMotion } from "motion/react";
import { Activity, ArrowUpRight, Mail, Megaphone, ShieldCheck, TrendingUp, Users } from "lucide-react";
import { Area, AreaChart, ResponsiveContainer, Tooltip, XAxis, YAxis } from "recharts";
import StatCard from "../components/StatCard";
import { Skeleton } from "../components/Skeleton";
import SStatCard from "./s/components/StatCard";
import SGlassCard from "./s/components/GlassCard";
import { cn } from "../utils/cn";
import { ModuleId } from "./registry";

/* ------------------------------------------------------------------ */
/* Deterministic seeded PRNG (mulberry32) — re-seeded on every launch. */
/* ------------------------------------------------------------------ */
export function mulberry32(seed: number) {
  let a = seed >>> 0;
  return () => {
    a |= 0;
    a = (a + 0x6d2b79f5) | 0;
    let t = Math.imul(a ^ (a >>> 15), 1 | a);
    t = (t + Math.imul(t ^ (t >>> 7), 61 | t)) ^ t;
    return ((t ^ (t >>> 14)) >>> 0) / 4294967296;
  };
}

export function hashModuleId(id: string): number {
  let h = 2166136261;
  for (let i = 0; i < id.length; i++) {
    h ^= id.charCodeAt(i);
    h = Math.imul(h, 16777619);
  }
  return h >>> 0;
}

/* Slow-motion reassembly curve mandated by the brief. */
export const ASSEMBLY_EASE: [number, number, number, number] = [0.22, 1, 0.36, 1];

interface PieceTransform {
  x: number;
  y: number;
  rotate: number;
  scale: number;
  delay: number;
  duration: number;
}

interface PieceSpec {
  key: string;
  span: string; // grid column span classes
  from: PieceTransform;
}

const MIN_DISTANCE = 240;
const MAX_DISTANCE = 720;
const MIN_STAGGER_BASE = 40;
const MAX_STAGGER_JITTER = 50; // stagger = i*55 + rand(40..90) per brief
const MIN_DURATION = 2.4;
const MAX_DURATION = 3.2;

export function buildPieceSpecs(rand: () => number, count: number): PieceSpec[] {
  const spans = [
    "sm:col-span-3 sm:row-span-1 col-span-6",
    "sm:col-span-3 sm:row-span-1 col-span-6",
    "sm:col-span-3 sm:row-span-1 col-span-6",
    "sm:col-span-3 sm:row-span-1 col-span-6",
    "sm:col-span-4 sm:row-span-2 col-span-6",
    "sm:col-span-2 sm:row-span-2 col-span-6",
    "col-span-6",
    "sm:col-span-2 col-span-6",
    "sm:col-span-2 col-span-6",
    "sm:col-span-2 col-span-6",
    "col-span-6",
  ];
  return Array.from({ length: count }, (_, i) => {
    const angle = rand() * Math.PI * 2;
    const distance = MIN_DISTANCE + rand() * (MAX_DISTANCE - MIN_DISTANCE);
    const direction = i % 2 === 0 ? 1 : -1; // pieces fly in from both sides of the canvas
    return {
      key: `piece-${i}`,
      span: spans[i % spans.length],
      from: {
        x: Math.cos(angle) * distance * direction,
        y: Math.sin(angle) * distance,
        rotate: (8 + rand() * 37) * (rand() > 0.5 ? 1 : -1),
        scale: 0.55 + rand() * 0.8,
        delay: i * 55 + MIN_STAGGER_BASE + rand() * MAX_STAGGER_JITTER,
        duration: MIN_DURATION + rand() * (MAX_DURATION - MIN_DURATION),
      },
    };
  });
}

/* ------------------------------------------------------------------ */
/* Real dashboard primitives rendered by the assembly grid             */
/* ------------------------------------------------------------------ */

const CHART_DATA = [
  { d: "Mon", v: 3200, b: 2100 },
  { d: "Tue", v: 4100, b: 2600 },
  { d: "Wed", v: 3800, b: 2400 },
  { d: "Thu", v: 5200, b: 3100 },
  { d: "Fri", v: 4800, b: 2900 },
  { d: "Sat", v: 6100, b: 3600 },
  { d: "Sun", v: 7400, b: 4200 },
];

const LIST_ROWS = [
  { email: "ava.reyes@northwind.io", badge: "DELIVERED" as const, tone: "text-emerald-300 bg-emerald-500/10 border-emerald-500/20" },
  { email: "marcus.chen@brightlab.co", badge: "OPENED" as const, tone: "text-sky-300 bg-sky-500/10 border-sky-500/20" },
  { email: "lena.hoffmann@vanta.dev", badge: "REPLIED" as const, tone: "text-violet-300 bg-violet-500/10 border-violet-500/20" },
  { email: "j.torres@quanticloud.ai", badge: "ACTIVE" as const, tone: "text-emerald-300 bg-emerald-500/10 border-emerald-500/20" },
  { email: "priya.nair@helioshift.com", badge: "QUEUED" as const, tone: "text-zinc-300 bg-white/5 border-white/10" },
];

interface AnimationProps {
  module: ModuleId;
  mode: "enter" | "exit";
  /** Re-seed source: Date.now() ^ hashModuleId(module) ^ launchSeq */
  seed: number;
  onDone: () => void;
  /** Accent colors from the active module theme (engineLabel uses it too). */
  accent: string;
  accentSoft: string;
}

export default function ModuleLaunchAnimation({ module, mode, seed, onDone, accent, accentSoft }: AnimationProps) {
  const prefersReducedMotion = useReducedMotion();
  const [play, setPlay] = useState(false);
  const [settled, setSettled] = useState<Set<number>>(new Set());
  const doneRef = useRef(false);
  const watchdogRef = useRef<number | null>(null);

  const specs = useMemo(
    () => buildPieceSpecs(mulberry32(seed), 11),
    [seed]
  );

  // Double-rAF: mount pieces in their hidden state first, then start the
  // timeline — guarantees the first paint of the overlay is cheap (no jank).
  useEffect(() => {
    if (prefersReducedMotion) {
      setPlay(true);
      setSettled(new Set(specs.map((_, i) => i)));
      return;
    }
    let raf2 = 0;
    const raf1 = requestAnimationFrame(() => {
      raf2 = requestAnimationFrame(() => setPlay(true));
    });
    return () => {
      cancelAnimationFrame(raf1);
      cancelAnimationFrame(raf2);
    };
  }, [prefersReducedMotion, specs]);

  const finish = useCallback(() => {
    if (doneRef.current) return;
    doneRef.current = true;
    onDone();
  }, [onDone]);

  // Watchdog is the single source of truth for completion (deterministic:
  // longest stagger + longest duration + margin). onAnimationComplete only
  // drives will-change cleanup.
  useEffect(() => {
    if (!play) return;
    const maxTime = Math.max(...specs.map((s) => s.from.delay + s.from.duration * 1000));
    watchdogRef.current = window.setTimeout(
      finish,
      prefersReducedMotion ? 0 : (mode === "enter" ? maxTime + 120 : maxTime) + 80
    );
    return () => {
      if (watchdogRef.current) window.clearTimeout(watchdogRef.current);
    };
  }, [play, specs, finish, mode, prefersReducedMotion]);

  const markSettled = useCallback((i: number) => {
    setSettled((prev) => {
      if (prev.has(i)) return prev;
      const next = new Set(prev);
      next.add(i);
      return next;
    });
  }, []);

  const isEnter = mode === "enter";
  const StatCardVariant = module === "s" ? SStatCard : StatCard;
  const Frame = module === "s" ? SGlassCard : React.Fragment;

  const frameProps = module === "s" ? { className: "p-4" } : {};

  return (
    <div
      className="absolute inset-0 z-30 flex items-center justify-center overflow-hidden p-4 md:p-8 pointer-events-none"
      aria-hidden="true"
      data-testid="module-launch-animation"
    >
      <div className="grid grid-cols-6 auto-rows-min gap-3 md:gap-4 w-full max-w-5xl">
        {specs.map((spec, i) => {
          const initial =
            isEnter && !prefersReducedMotion
              ? { x: spec.from.x, y: spec.from.y, rotate: spec.from.rotate, scale: spec.from.scale, opacity: 0 }
              : isEnter
                ? { x: 0, y: 0, rotate: 0, scale: 1, opacity: 1 }
                : { x: 0, y: 0, rotate: 0, scale: 1, opacity: 1 };
          const animate = isEnter
            ? { x: 0, y: 0, rotate: 0, scale: 1, opacity: 1 }
            : prefersReducedMotion
              ? { x: 0, y: 0, opacity: 0 }
              : {
                  x: spec.from.x,
                  y: spec.from.y,
                  rotate: spec.from.rotate,
                  scale: spec.from.scale,
                  opacity: 0,
                };

          return (
            <motion.div
              key={`${spec.key}-${seed}`}
              className={cn("module-launch-piece min-w-0", spec.span, settled.has(i) && "module-launch-settled")}
              initial={initial}
              animate={play ? animate : initial}
              transition={
                prefersReducedMotion
                  ? { duration: 0 }
                  : {
                      delay: (isEnter ? spec.from.delay : i * 24) / 1000,
                      duration: isEnter ? spec.from.duration : 0.85,
                      ease: ASSEMBLY_EASE,
                    }
              }
              onAnimationComplete={() => {
                if (play) markSettled(i);
              }}
              style={{ transformOrigin: "center center" }}
            >
              <Piece
                index={i}
                module={module}
                accent={accent}
                accentSoft={accentSoft}
                StatCardVariant={StatCardVariant}
                Frame={Frame}
                frameProps={frameProps}
              />
            </motion.div>
          );
        })}
      </div>

      {/* Engine strip — reassembles last, identifies the module being launched */}
      <motion.div
        className="absolute bottom-6 left-1/2 -translate-x-1/2 flex items-center gap-2 px-3 py-1.5 rounded-full border border-white/10 bg-black/50 backdrop-blur-md"
        initial={{ opacity: 0, y: 14 }}
        animate={play ? { opacity: 1, y: 0 } : { opacity: 0, y: 14 }}
        transition={prefersReducedMotion ? { duration: 0 } : { delay: 0.35, duration: 0.7, ease: ASSEMBLY_EASE }}
      >
        <span className="w-1.5 h-1.5 rounded-full animate-pulse" style={{ backgroundColor: accent, boxShadow: `0 0 10px ${accent}` }} />
        <span className="text-[10px] font-mono uppercase tracking-[0.2em] text-zinc-400">
          {isEnter ? "Assembling" : "Releasing"} {module === "s" ? "ModuleS" : "ModuleE"} workspace
        </span>
        <span className="text-[10px] font-mono" style={{ color: accentSoft }}>
          {Math.round(MIN_DURATION * 10) / 10}–{MAX_DURATION}s
        </span>
      </motion.div>
    </div>
  );
}

/* ------------------------------------------------------------------ */
/* Piece renderer — every slot is a REAL platform component            */
/* ------------------------------------------------------------------ */

interface PieceProps {
  index: number;
  module: ModuleId;
  accent: string;
  accentSoft: string;
  StatCardVariant: typeof StatCard;
  Frame: React.ComponentType<{ children?: React.ReactNode; className?: string }> | typeof React.Fragment;
  frameProps: Record<string, unknown>;
}

function Piece({ index, module, accent, accentSoft, StatCardVariant, Frame, frameProps }: PieceProps) {
  switch (index) {
    case 0:
      return (
        <StatCardVariant
          title="Total Leads"
          value="12,847"
          icon={Users}
          iconColor="indigo"
          change={{ value: "+12.4%", isPositive: true, period: "vs last week" }}
        />
      );
    case 1:
      return (
        <StatCardVariant
          title="Active Campaigns"
          value="24"
          icon={Megaphone}
          iconColor="emerald"
          change={{ value: "3 launching", isPositive: null }}
        />
      );
    case 2:
      return (
        <StatCardVariant
          title="Reply Rate"
          value="8.2%"
          icon={Mail}
          iconColor="purple"
          change={{ value: "+0.9%", isPositive: true, period: "7-day avg" }}
        />
      );
    case 3:
      return (
        <StatCardVariant
          title="Deliverability"
          value="98.2%"
          icon={ShieldCheck}
          iconColor="teal"
          subtitle="Reputation shield active"
          progress={98}
        />
      );
    case 4:
      return (
        <Frame {...frameProps}>
          <div className="flex items-center justify-between mb-2">
            <div className="flex items-center gap-2 min-w-0">
              <TrendingUp className="w-3.5 h-3.5 shrink-0" style={{ color: accent }} />
              <span className="text-[11px] font-mono uppercase tracking-wider text-zinc-400 truncate">Sequence telemetry</span>
            </div>
            <span className="text-[10px] font-mono px-1.5 py-0.5 rounded border" style={{ color: accentSoft, borderColor: accentSoft + "55", backgroundColor: accentSoft + "14" }}>
              LIVE
            </span>
          </div>
          <div className="h-28 -ml-2">
            <ResponsiveContainer width="100%" height="100%">
              <AreaChart data={CHART_DATA} margin={{ top: 4, right: 4, bottom: 0, left: 4 }}>
                <defs>
                  <linearGradient id={`launch-grad-${module}`} x1="0" y1="0" x2="0" y2="1">
                    <stop offset="0%" stopColor={accent} stopOpacity={0.45} />
                    <stop offset="100%" stopColor={accent} stopOpacity={0.02} />
                  </linearGradient>
                </defs>
                <XAxis dataKey="d" hide />
                <YAxis hide />
                <Tooltip cursor={{ stroke: accent + "55" }} contentStyle={{ background: "#0c0d10", border: "1px solid rgba(255,255,255,0.1)", borderRadius: 8, fontSize: 10 }} />
                <Area type="monotone" dataKey="b" stroke="transparent" fill={`url(#launch-grad-${module})`} isAnimationActive={false} />
                <Area type="monotone" dataKey="v" stroke={accent} strokeWidth={1.5} fill="transparent" isAnimationActive={false} dot={false} />
              </AreaChart>
            </ResponsiveContainer>
          </div>
        </Frame>
      );
    case 5:
      return (
        <Frame {...frameProps}>
          <div className="flex items-center gap-2 mb-2">
            <Activity className="w-3.5 h-3.5 shrink-0" style={{ color: accent }} />
            <span className="text-[11px] font-mono uppercase tracking-wider text-zinc-400 truncate">Live feed</span>
          </div>
          <div className="space-y-2">
            {LIST_ROWS.map((row) => (
              <div key={row.email} className="flex items-center justify-between gap-2">
                <div className="flex items-center gap-2 min-w-0">
                  <span className="w-1.5 h-1.5 rounded-full shrink-0" style={{ backgroundColor: accent }} />
                  <span className="text-[11px] text-zinc-300 truncate">{row.email}</span>
                </div>
                <span className={cn("text-[8px] font-bold tracking-wider px-1.5 py-0.5 rounded border shrink-0", row.tone)}>{row.badge}</span>
              </div>
            ))}
          </div>
        </Frame>
      );
    case 6:
      return (
        <div className="flex items-center gap-2 flex-wrap">
          {["SEQUENCES", "WARMUP", "UNIBOX"].map((tag) => (
            <span key={tag} className="text-[9px] font-bold tracking-[0.18em] px-2 py-1 rounded-md border border-white/10 bg-white/5 text-zinc-300">
              {tag}
            </span>
          ))}
          <span className="text-[9px] font-bold tracking-[0.18em] px-2 py-1 rounded-md border" style={{ color: accentSoft, borderColor: accentSoft + "55", backgroundColor: accentSoft + "14" }}>
            DELIVERABILITY
          </span>
        </div>
      );
    case 7:
      return (
        <StatCardVariant title="Open Rate" value="64.7%" icon={Mail} iconColor="blue" change={{ value: "+2.1%", isPositive: true }} />
      );
    case 8:
      return <StatCardVariant title="Bounce Rate" value="0.4%" icon={ArrowUpRight} iconColor="rose" change={{ value: "-0.2%", isPositive: true }} />;
    case 9:
      return (
        <StatCardVariant title="Mailboxes Rotating" value="38" icon={Users} iconColor="amber" subtitle="Multi-mailbox rotation on" />
      );
    default:
      return (
        <div className="space-y-2.5">
          <Skeleton className="h-3 w-1/3" />
          <Skeleton className="h-3 w-2/3" />
          <Skeleton className="h-3 w-1/2" />
        </div>
      );
  }
}