"use client";

import { useMemo } from "react";
import { FileText, Upload, Edit2 } from "lucide-react";
import type { ApiDocument } from "@/lib/api/types";
import { cn } from "@/lib/utils";
import { documentKindLabel, documentStatusLabel } from "./utils";
import { WorkspaceSearch } from "./WorkspacePanelPrimitives";

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 formatEducationSummary(document: ApiDocument): string {
  const status = document.education_extraction_status;
  const warnings = document.education_warnings_json ?? [];
  if (status === "extraction_failed") return "Extraction failed";
  if (status === "needs_review") return warnings[0] ? `Needs review - ${warnings[0]}` : "Needs review";
  if (document.material_type === "syllabus") {
    const count = document.syllabus_items_count ?? 0;
    return count > 0 ? `Syllabus - ${count} chapter${count === 1 ? "" : "s"} extracted` : "Syllabus - extracting topics";
  }
  if (document.material_type === "question_paper") {
    const count = document.pyq_questions_count ?? 0;
    const years = (document.pyq_years_json ?? []).join(", ");
    if (count > 0) {
      return `PYQ paper${years ? ` - ${years}` : ""} - ${count} question${count === 1 ? "" : "s"} extracted`;
    }
    return "Question paper - no questions extracted yet";
  }
  if (document.status === "ready") return "Generic notes - no PYQ data";
  return documentStatusLabel(document.status);
}

type SourceRailProps = {
  documents: ApiDocument[];
  selectedSourceIds: string[];
  isLoading: boolean;
  search: string;
  onSearchChange: (value: string) => void;
  onToggleSource: (id: string) => void;
  onUpload: () => void;
  onEditClassification?: (documentId: string, documentTitle: string, currentMaterialType: string | null) => void;
};

export function SourceRail({
  documents,
  selectedSourceIds,
  isLoading,
  search,
  onSearchChange,
  onToggleSource,
  onUpload,
  onEditClassification,
}: SourceRailProps) {
  const filtered = useMemo(() => {
    const query = search.trim().toLowerCase();
    if (!query) return documents;
    return documents.filter((document) =>
      [document.title, document.subject, document.chapter, document.syllabus, document.file_type, document.material_type]
        .filter(Boolean)
        .some((value) => String(value).toLowerCase().includes(query)),
    );
  }, [documents, search]);

  return (
    <div className="flex h-full min-h-0 flex-col rounded-[1.25rem] border border-white/[0.075] bg-[#080808]/88">
      <div className="border-b border-white/[0.06] p-4">
        <div className="flex items-start justify-between gap-3">
          <div>
            <p className="text-sm font-semibold text-white">Sources</p>
            <p className="mt-0.5 text-xs text-white/36">
              {documents.length ? `${documents.filter((document) => document.status === "ready").length} ready of ${documents.length}` : "Upload study material"}
            </p>
          </div>
          <button
            type="button"
            onClick={onUpload}
            className="grid size-9 shrink-0 place-items-center rounded-xl bg-white text-black transition hover:bg-white/90 focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-white/28"
            aria-label="Upload source"
          >
            <Upload className="size-4" />
          </button>
        </div>
        <div className="mt-3">
          <WorkspaceSearch value={search} onChange={onSearchChange} placeholder="Search sources" />
        </div>
      </div>

      <div className="min-h-0 flex-1 overflow-y-auto p-3 [scrollbar-width:none] [&::-webkit-scrollbar]:hidden">
        {isLoading ? (
          <div className="space-y-2">
            {Array.from({ length: 5 }).map((_, index) => (
              <div key={index} className="h-16 animate-pulse rounded-2xl border border-white/[0.06] bg-white/[0.025]" />
            ))}
          </div>
        ) : filtered.length === 0 ? (
          <div className="flex min-h-[14rem] flex-col items-center justify-center rounded-2xl border border-dashed border-white/[0.08] px-5 text-center">
            <FileText className="size-7 text-white/32" />
            <p className="mt-3 text-sm font-semibold text-white/72">No sources yet</p>
            <p className="mt-1 text-xs leading-5 text-white/36">Upload a selectable-text PDF or TXT file, or paste syllabus text.</p>
            <button
              type="button"
              onClick={onUpload}
              className="mt-4 inline-flex min-h-10 items-center gap-2 rounded-xl bg-white px-3 text-xs font-bold text-black transition hover:bg-white/90"
            >
              <Upload className="size-3.5" />
              Add source
            </button>
          </div>
        ) : (
          <div className="space-y-2">
            {filtered.map((document) => {
              const active = selectedSourceIds.includes(document.id);
              return (
                <div
                  key={document.id}
                  className={cn(
                    "group flex w-full min-w-0 items-start gap-2 rounded-2xl border p-3 text-left transition",
                    active
                      ? "border-white/[0.22] bg-white/[0.08]"
                      : "border-white/[0.065] bg-white/[0.025] hover:border-white/[0.14] hover:bg-white/[0.045]",
                  )}
                >
                  <button
                    type="button"
                    onClick={() => onToggleSource(document.id)}
                    className="flex min-w-0 flex-1 items-start gap-3 text-left focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-white/20"
                  >
                    <span className={cn("mt-0.5 grid size-9 shrink-0 place-items-center rounded-xl border", active ? "border-white/20 bg-white text-black" : "border-white/[0.08] bg-white/[0.035] text-white/58")}>
                      <FileText className="size-4" />
                    </span>
                    <span className="min-w-0 flex-1">
                      <span className="line-clamp-2 text-sm font-semibold leading-5 text-white/86">{document.title}</span>
                      <span className="mt-1 flex items-center flex-wrap gap-1.5 text-[11px] text-white/36">
                        <span className="truncate">{document.subject || documentKindLabel(document)}</span>
                        <span className="size-1 rounded-full bg-white/24" />
                        <span>{documentStatusLabel(document.status)}</span>
                        {document.material_type && document.material_type !== "unknown" && (
                          <>
                            <span className="size-1 rounded-full bg-white/24" />
                            <span className={cn(
                              "rounded-full border px-1.5 py-0.5 text-[9px] font-medium",
                              getMaterialTypeBadgeColor(document.material_type)
                            )}>
                              {formatMaterialType(document.material_type)}
                            </span>
                          </>
                        )}
                      </span>
                      <span className="mt-1 block truncate text-[10.5px] leading-4 text-white/28">
                        {formatEducationSummary(document)}
                      </span>
                    </span>
                  </button>
                  {document.status === "ready" && onEditClassification && (
                    <button
                      type="button"
                      onClick={() => onEditClassification(document.id, document.title, document.material_type ?? null)}
                      className="mt-0.5 grid size-7 shrink-0 place-items-center rounded-lg border border-white/[0.08] bg-white/[0.02] text-white/50 transition-all hover:border-white/20 hover:bg-white/[0.06] hover:text-white focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-white/20"
                      aria-label={`Edit classification for ${document.title}`}
                    >
                      <Edit2 className="size-3" strokeWidth={2} />
                    </button>
                  )}
                </div>
              );
            })}
          </div>
        )}
      </div>
    </div>
  );
}