"use client";

import Link from "next/link";
import type { ElementType, FormEvent, ReactNode } from "react";
import {
  AlertCircle,
  ArrowRight,
  Check,
  ChevronRight,
  LoaderCircle,
  Search,
  Sparkles,
} from "lucide-react";
import { cn } from "@/lib/utils";
import { normalizeApiError } from "@/lib/api/client";

type Tone = "amber" | "emerald" | "blue" | "violet" | "neutral";

const toneStyles: Record<
  Tone,
  {
    icon: string;
    border: string;
    glow: string;
    text: string;
  }
> = {
  amber: {
    icon: "border-amber-300/15 bg-amber-300/[0.08] text-amber-200",
    border: "border-amber-300/12 hover:border-amber-200/30",
    glow: "before:bg-amber-400/[0.08]",
    text: "text-amber-100",
  },
  emerald: {
    icon: "border-emerald-300/15 bg-emerald-300/[0.08] text-emerald-200",
    border: "border-emerald-300/12 hover:border-emerald-200/30",
    glow: "before:bg-emerald-400/[0.08]",
    text: "text-emerald-100",
  },
  blue: {
    icon: "border-blue-300/15 bg-blue-300/[0.08] text-blue-200",
    border: "border-blue-300/12 hover:border-blue-200/30",
    glow: "before:bg-blue-400/[0.08]",
    text: "text-blue-100",
  },
  violet: {
    icon: "border-fuchsia-200/15 bg-fuchsia-200/[0.06] text-fuchsia-100",
    border: "border-fuchsia-200/10 hover:border-fuchsia-100/24",
    glow: "before:bg-fuchsia-300/[0.06]",
    text: "text-fuchsia-100",
  },
  neutral: {
    icon: "border-white/[0.08] bg-white/[0.04] text-white/78",
    border: "border-white/[0.08] hover:border-white/[0.16]",
    glow: "before:bg-white/[0.05]",
    text: "text-white",
  },
};

const panelVariants = {
  compact: "rounded-2xl p-4 sm:p-5",
  standard: "rounded-[1.35rem] p-5 sm:p-6",
  hero: "rounded-[1.6rem] p-6 sm:p-8",
};

function cleanStudentError(error: unknown) {
  const normalized = normalizeApiError(error);
  const lower = normalized.toLowerCase();
  const unsafeTerms = [
    "backend",
    "chunk",
    "token",
    "retrieval",
    "mock",
    "raw json",
    "debug",
    "server error",
    "api failed",
    "vector db",
    "embedding",
    "remotion",
    "provider",
    "model",
    "stack trace",
    "file path",
    "extraction_error",
    "extracted_text",
    "document path",
    "private filename",
  ];

  if (unsafeTerms.some((term) => lower.includes(term))) {
    return "DocDoe could not prepare this right now. Please try again.";
  }

  if (/[{}[\]\\]/.test(normalized) || normalized.length > 180) {
    return "DocDoe could not prepare this right now. Please try again.";
  }

  return normalized || "DocDoe could not prepare this right now. Please try again.";
}

export interface StudentPageShellProps {
  eyebrow?: string;
  title?: string;
  description?: string;
  action?: ReactNode;
  children: ReactNode;
  className?: string;
  contentClassName?: string;
  variant?: "standard" | "dense" | "wide" | "centered";
}

export function StudentPageShell({
  eyebrow,
  title,
  description,
  action,
  children,
  className,
  contentClassName,
  variant = "standard",
}: StudentPageShellProps) {
  const widths = {
    dense: "max-w-5xl",
    standard: "max-w-6xl",
    wide: "max-w-7xl",
    centered: "max-w-4xl",
  };

  return (
    <section
      className={cn(
        "relative mx-auto w-full px-4 py-6 sm:px-6 lg:px-8",
        variant === "centered" && "min-h-[calc(100vh-8rem)]",
        className,
      )}
    >
      <div className={cn("relative mx-auto w-full", widths[variant], contentClassName)}>
        {(eyebrow || title || description || action) && (
          <div className="mb-5 flex flex-col gap-4 sm:mb-7 lg:flex-row lg:items-end lg:justify-between">
            <div className="min-w-0 space-y-2">
              {eyebrow && (
                <p className="text-[11px] font-semibold uppercase text-white/46">
                  {eyebrow}
                </p>
              )}
              {title && (
                <h1 className="max-w-3xl text-balance text-2xl font-semibold text-white sm:text-[2rem]">
                  {title}
                </h1>
              )}
              {description && (
                <p className="max-w-2xl text-sm leading-6 text-white/62">
                  {description}
                </p>
              )}
            </div>
            {action && <div className="shrink-0">{action}</div>}
          </div>
        )}
        {children}
      </div>
    </section>
  );
}

export interface PremiumPanelProps {
  children: ReactNode;
  className?: string;
  variant?: keyof typeof panelVariants;
  tone?: Tone;
  interactive?: boolean;
  as?: "div" | "section" | "article";
}

export function PremiumPanel({
  children,
  className,
  variant = "standard",
  tone = "neutral",
  interactive = false,
  as: Component = "div",
}: PremiumPanelProps) {
  return (
    <Component
      className={cn(
        "relative overflow-hidden border bg-[linear-gradient(145deg,rgba(255,255,255,0.055),rgba(255,255,255,0.018))] shadow-[0_18px_60px_rgba(0,0,0,0.34),inset_0_1px_0_rgba(255,255,255,0.045)] backdrop-blur-xl",
        "before:pointer-events-none before:absolute before:-right-20 before:-top-20 before:size-48 before:rounded-full before:blur-3xl",
        panelVariants[variant],
        toneStyles[tone].border,
        toneStyles[tone].glow,
        interactive && "transition duration-200 hover:-translate-y-0.5 focus-within:border-white/20",
        className,
      )}
    >
      <div className="relative">{children}</div>
    </Component>
  );
}

export interface ActionTileProps {
  title: string;
  description: string;
  icon: ElementType;
  href?: string;
  onClick?: () => void;
  cta?: string;
  tone?: Tone;
  disabled?: boolean;
  className?: string;
}

export function ActionTile({
  title,
  description,
  icon: Icon,
  href,
  onClick,
  cta = "Open",
  tone = "neutral",
  disabled = false,
  className,
}: ActionTileProps) {
  const content = (
    <>
      <div className="flex items-start gap-3.5">
        <span
          className={cn(
            "grid size-10 shrink-0 place-items-center rounded-xl border",
            toneStyles[tone].icon,
          )}
        >
          <Icon className="size-5" />
        </span>
        <span className="min-w-0 flex-1">
          <span className="block text-sm font-semibold text-white">{title}</span>
          <span className="mt-1 block text-[12.5px] leading-5 text-white/58">{description}</span>
        </span>
      </div>
      <span className={cn("mt-5 inline-flex items-center gap-1.5 text-xs font-semibold", toneStyles[tone].text)}>
        {cta}
        <ChevronRight className="size-3.5" />
      </span>
    </>
  );

  const classes = cn(
    "group block h-full rounded-2xl border bg-white/[0.025] p-4 text-left shadow-[inset_0_1px_0_rgba(255,255,255,0.035)] transition duration-200 hover:-translate-y-0.5 hover:bg-white/[0.04] focus:outline-none focus-visible:ring-2 focus-visible:ring-white/22",
    toneStyles[tone].border,
    disabled && "pointer-events-none opacity-45",
    className,
  );

  if (href && !disabled) {
    return (
      <Link href={href} className={classes}>
        {content}
      </Link>
    );
  }

  if (onClick && !disabled) {
    return (
      <button type="button" onClick={onClick} className={classes}>
        {content}
      </button>
    );
  }

  return <div className={classes}>{content}</div>;
}

export interface EmptyWorkspaceProps {
  icon?: ElementType;
  title: string;
  description: string;
  examples?: string[];
  actionText?: string;
  actionHref?: string;
  onAction?: () => void;
  className?: string;
}

export function EmptyWorkspace({
  icon: Icon = Sparkles,
  title,
  description,
  examples = [],
  actionText,
  actionHref,
  onAction,
  className,
}: EmptyWorkspaceProps) {
  const action = actionText ? (
    actionHref ? (
      <Link
        href={actionHref}
        className="inline-flex items-center justify-center gap-2 rounded-xl border border-white/[0.12] bg-white/[0.055] px-4 py-2 text-sm font-semibold text-white transition hover:bg-white/[0.09] focus:outline-none focus-visible:ring-2 focus-visible:ring-white/22"
      >
        {actionText}
        <ArrowRight className="size-4" />
      </Link>
    ) : (
      <button
        type="button"
        onClick={onAction}
        className="inline-flex items-center justify-center gap-2 rounded-xl border border-white/[0.12] bg-white/[0.055] px-4 py-2 text-sm font-semibold text-white transition hover:bg-white/[0.09] focus:outline-none focus-visible:ring-2 focus-visible:ring-white/22"
      >
        {actionText}
        <ArrowRight className="size-4" />
      </button>
    )
  ) : null;

  return (
    <PremiumPanel className={cn("flex min-h-[22rem] items-center justify-center text-center", className)}>
      <div className="mx-auto max-w-md">
        <div className="mx-auto grid size-12 place-items-center rounded-2xl border border-white/[0.08] bg-white/[0.04] text-white/70">
          <Icon className="size-5" />
        </div>
        <h2 className="mt-4 text-lg font-semibold text-white">{title}</h2>
        <p className="mt-2 text-sm leading-6 text-white/58">{description}</p>
        {examples.length > 0 && (
          <div className="mt-5 flex flex-wrap justify-center gap-2">
            {examples.map((example) => (
              <span
                key={example}
                className="rounded-full border border-white/[0.08] bg-white/[0.035] px-3 py-1.5 text-xs text-white/58"
              >
                {example}
              </span>
            ))}
          </div>
        )}
        {action && <div className="mt-6">{action}</div>}
      </div>
    </PremiumPanel>
  );
}

export interface StudyCommandBarProps {
  value: string;
  onChange: (value: string) => void;
  onSubmit: (value: string) => void;
  placeholder?: string;
  submitLabel?: string;
  chips?: string[];
  className?: string;
  disabled?: boolean;
}

export function StudyCommandBar({
  value,
  onChange,
  onSubmit,
  placeholder = "Search your studies",
  submitLabel = "Start",
  chips = [],
  className,
  disabled = false,
}: StudyCommandBarProps) {
  function handleSubmit(event: FormEvent<HTMLFormElement>) {
    event.preventDefault();
    const trimmed = value.trim();
    if (trimmed && !disabled) onSubmit(trimmed);
  }

  return (
    <PremiumPanel variant="compact" className={cn("space-y-3", className)} interactive>
      <form onSubmit={handleSubmit} className="flex flex-col gap-3 sm:flex-row">
        <label className="relative min-w-0 flex-1">
          <span className="sr-only">Study request</span>
          <Search className="pointer-events-none absolute left-3.5 top-1/2 size-4 -translate-y-1/2 text-white/36" />
          <input
            value={value}
            onChange={(event) => onChange(event.target.value)}
            placeholder={placeholder}
            disabled={disabled}
            className="h-12 w-full rounded-xl border border-white/[0.08] bg-black/28 px-10 text-sm text-white outline-none transition placeholder:text-white/32 focus:border-white/22 focus:bg-black/38"
          />
        </label>
        <button
          type="submit"
          disabled={disabled || !value.trim()}
          className="inline-flex h-12 items-center justify-center gap-2 rounded-xl bg-white px-5 text-sm font-semibold text-black transition hover:bg-white/88 disabled:cursor-not-allowed disabled:opacity-45"
        >
          {submitLabel}
          <ArrowRight className="size-4" />
        </button>
      </form>
      {chips.length > 0 && (
        <div className="flex flex-wrap gap-2">
          {chips.map((chip) => (
            <button
              key={chip}
              type="button"
              onClick={() => onChange(chip)}
              className="rounded-full border border-white/[0.08] bg-white/[0.03] px-3 py-1.5 text-xs text-white/62 transition hover:border-white/[0.16] hover:text-white focus:outline-none focus-visible:ring-2 focus-visible:ring-white/22"
            >
              {chip}
            </button>
          ))}
        </div>
      )}
    </PremiumPanel>
  );
}

export interface SafeErrorBannerProps {
  error: unknown;
  title?: string;
  className?: string;
}

export function SafeErrorBanner({ error, title = "We could not finish that", className }: SafeErrorBannerProps) {
  return (
    <div
      role="alert"
      className={cn(
        "rounded-2xl border border-rose-300/18 bg-rose-300/[0.055] p-4 text-sm text-rose-50 shadow-[inset_0_1px_0_rgba(255,255,255,0.04)]",
        className,
      )}
    >
      <div className="flex gap-3">
        <AlertCircle className="mt-0.5 size-4 shrink-0 text-rose-200" />
        <div className="min-w-0">
          <p className="font-semibold">{title}</p>
          <p className="mt-1 leading-5 text-rose-50/72">{cleanStudentError(error)}</p>
        </div>
      </div>
    </div>
  );
}

export interface GeneratorWorkspaceProps {
  title: string;
  description: string;
  setup: ReactNode;
  children?: ReactNode;
  empty?: ReactNode;
  loading?: boolean;
  loadingLabel?: string;
  error?: unknown;
  footer?: ReactNode;
  className?: string;
}

export function GeneratorWorkspace({
  title,
  description,
  setup,
  children,
  empty,
  loading = false,
  loadingLabel = "Preparing your study output",
  error,
  footer,
  className,
}: GeneratorWorkspaceProps) {
  return (
    <div className={cn("grid gap-5 lg:grid-cols-[minmax(17rem,0.82fr)_minmax(0,1.5fr)]", className)}>
      <PremiumPanel className="h-fit" variant="standard">
        <div className="mb-5">
          <p className="text-[11px] font-semibold uppercase text-white/42">Setup</p>
          <h2 className="mt-1 text-lg font-semibold text-white">{title}</h2>
          <p className="mt-2 text-sm leading-6 text-white/56">{description}</p>
        </div>
        {setup}
      </PremiumPanel>
      <div className="min-w-0 space-y-4">
        {error ? <SafeErrorBanner error={error} /> : null}
        {loading ? (
          <PremiumPanel className="min-h-[24rem]">
            <div className="flex min-h-[18rem] flex-col items-center justify-center text-center">
              <LoaderCircle className="size-7 animate-spin text-white/68" />
              <h3 className="mt-4 text-base font-semibold text-white">{loadingLabel}</h3>
              <p className="mt-2 max-w-sm text-sm leading-6 text-white/54">
                Keep this open while DocDoe prepares the result.
              </p>
            </div>
          </PremiumPanel>
        ) : (
          children ?? empty
        )}
        {footer}
      </div>
    </div>
  );
}

export interface StatusTimelineStep {
  id: string;
  label: string;
  description?: string;
  status?: "complete" | "current" | "waiting" | "error";
}

export interface StatusTimelineProps {
  steps: StatusTimelineStep[];
  className?: string;
}

export function StatusTimeline({ steps, className }: StatusTimelineProps) {
  return (
    <div className={cn("space-y-3", className)}>
      {steps.map((step) => {
        const status = step.status ?? "waiting";
        return (
          <div key={step.id} className="flex gap-3">
            <span
              className={cn(
                "mt-0.5 grid size-7 shrink-0 place-items-center rounded-full border",
                status === "complete" && "border-emerald-300/25 bg-emerald-300/[0.08] text-emerald-100",
                status === "current" && "border-white/20 bg-white/[0.08] text-white",
                status === "waiting" && "border-white/[0.08] bg-white/[0.025] text-white/34",
                status === "error" && "border-rose-300/22 bg-rose-300/[0.08] text-rose-100",
              )}
            >
              {status === "complete" ? (
                <Check className="size-3.5" />
              ) : status === "current" ? (
                <LoaderCircle className="size-3.5 animate-spin" />
              ) : status === "error" ? (
                <AlertCircle className="size-3.5" />
              ) : (
                <span className="size-1.5 rounded-full bg-current" />
              )}
            </span>
            <div className="min-w-0 pb-1">
              <p className="text-sm font-semibold text-white">{step.label}</p>
              {step.description && <p className="mt-0.5 text-xs leading-5 text-white/50">{step.description}</p>}
            </div>
          </div>
        );
      })}
    </div>
  );
}