"use client";

import { FileText, X } from "lucide-react";
import type { ApiDocument } from "@/lib/api/types";
import { cn } from "@/lib/utils";

function formatMaterialType(materialType: string | null | undefined): string {
  if (!materialType || materialType === "unknown") return "Unclassified";
  return materialType.replace(/_/g, " ").replace(/\b\w/g, (char) => char.toUpperCase());
}

function getMaterialTypeBadgeColor(materialType: string | null | undefined): string {
  if (!materialType || materialType === "unknown") {
    return "border-white/12 bg-white/[0.04] text-white/46";
  }
  const colors: Record<string, string> = {
    notes: "border-white/14 bg-white/[0.06] text-white/72",
    chapter: "border-blue-300/16 bg-blue-400/[0.08] text-blue-200/80",
    textbook: "border-emerald-300/16 bg-emerald-400/[0.08] text-emerald-200/80",
    handwritten_notes: "border-amber-300/16 bg-amber-400/[0.08] text-amber-200/80",
    question_paper: "border-rose-300/16 bg-rose-400/[0.08] text-rose-200/80",
    pyq_collection: "border-orange-300/16 bg-orange-400/[0.08] text-orange-200/80",
    syllabus: "border-cyan-300/16 bg-cyan-400/[0.08] text-cyan-200/80",
    formula_sheet: "border-pink-300/16 bg-pink-400/[0.08] text-pink-200/80",
    mixed: "border-white/14 bg-white/[0.06] text-white/72",
  };
  return colors[materialType] || colors.notes;
}

function compactEducationBadge(document: ApiDocument): string | null {
  if (document.education_extraction_status === "extraction_failed") return "Extraction failed";
  if (document.education_extraction_status === "needs_review") return "Needs review";
  if (document.material_type === "syllabus" && (document.syllabus_items_count ?? 0) > 0) {
    return `${document.syllabus_items_count} topics`;
  }
  if (document.material_type === "question_paper" && (document.pyq_questions_count ?? 0) > 0) {
    return `${document.pyq_questions_count} PYQ`;
  }
  return null;
}

export function SourcePill({
  document,
  active,
  onToggle,
  onRemove,
}: {
  document: ApiDocument;
  active: boolean;
  onToggle: () => void;
  onRemove?: () => void;
}) {
  const educationBadge = compactEducationBadge(document);
  return (
    <button
      type="button"
      onClick={onToggle}
      className={cn(
        "group inline-flex min-w-0 items-center gap-2 rounded-full border px-3 py-1.5 text-xs font-semibold transition focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-white/22",
        active
          ? "border-white/[0.2] bg-white text-black"
          : "border-white/[0.1] bg-white/[0.035] text-white/58 hover:border-white/[0.18] hover:text-white",
      )}
    >
      <FileText className="size-3.5 shrink-0" />
      <span className="max-w-[9rem] truncate sm:max-w-[12rem]">{document.title}</span>
      <span className={cn("size-1.5 rounded-full", document.status === "ready" ? "bg-current" : "bg-current opacity-45")} />
      {document.material_type && document.material_type !== "unknown" && (
        <span className={cn(
          "rounded-full border px-1.5 py-0.5 text-[9px] font-medium",
          active ? getMaterialTypeBadgeColor(document.material_type).replace("text-", "text-black/") : getMaterialTypeBadgeColor(document.material_type)
        )}>
          {formatMaterialType(document.material_type)}
        </span>
      )}
      {educationBadge ? (
        <span className={cn(
          "rounded-full border px-1.5 py-0.5 text-[9px] font-medium",
          active ? "border-black/10 bg-black/[0.04] text-black/65" : "border-white/[0.08] bg-white/[0.025] text-white/40",
        )}>
          {educationBadge}
        </span>
      ) : null}
      {onRemove ? (
        <span
          role="button"
          tabIndex={-1}
          aria-label={`Remove ${document.title}`}
          onClick={(event) => {
            event.stopPropagation();
            onRemove();
          }}
          className="ml-0.5 rounded-full opacity-55 transition group-hover:opacity-100"
        >
          <X className="size-3.5" />
        </span>
      ) : null}
    </button>
  );
}

export function SelectedSourcesStrip({
  selectedDocuments,
  documents,
  onToggleSource,
  onClear,
}: {
  selectedDocuments: ApiDocument[];
  documents: ApiDocument[];
  onToggleSource: (id: string) => void;
  onClear: () => void;
}) {
  const previewDocuments = selectedDocuments.length > 0 ? selectedDocuments : documents.slice(0, 4);
  if (previewDocuments.length === 0) return null;

  return (
    <div className="flex min-w-0 max-w-full flex-col items-start gap-2 sm:flex-row sm:items-center">
      <span className="text-[11px] font-semibold uppercase tracking-[0.16em] text-white/34">
        {selectedDocuments.length > 0 ? "Selected sources" : "Recent sources"}
      </span>
      <div className="flex w-full min-w-0 max-w-full gap-2 overflow-x-auto pb-1 [scrollbar-width:none] sm:flex-1 [&::-webkit-scrollbar]:hidden">
        {previewDocuments.map((document) => (
          <SourcePill
            key={document.id}
            document={document}
            active={selectedDocuments.some((item) => item.id === document.id)}
            onToggle={() => onToggleSource(document.id)}
            onRemove={selectedDocuments.some((item) => item.id === document.id) ? () => onToggleSource(document.id) : undefined}
          />
        ))}
      </div>
      {selectedDocuments.length > 0 ? (
        <button
          type="button"
          onClick={onClear}
          className="rounded-full px-2.5 py-1 text-[11px] font-semibold text-white/38 transition hover:bg-white/[0.04] hover:text-white/70"
        >
          Clear
        </button>
      ) : null}
    </div>
  );
}