import { createFileRoute } from "@tanstack/react-router";
import { useState } from "react";
import { toast } from "sonner";
import { useQuery, useMutation, useQueryClient } from "@tanstack/react-query";
import {
  getSavedKeywords,
  removeSavedKeyword,
} from "@/serverFunctions/keywords";
import { Trash2, Download, Search, Loader2, AlertCircle } from "lucide-react";
import { buildCsv, downloadCsv } from "@/client/lib/csv";
import { getStandardErrorMessage } from "@/client/lib/error-messages";

export const Route = createFileRoute("/p/$projectId/saved")({
  component: SavedKeywordsPage,
});

function SavedKeywordsPage() {
  const { projectId } = Route.useParams();
  const queryClient = useQueryClient();
  const [removeError, setRemoveError] = useState<string | null>(null);
  const [removingId, setRemovingId] = useState<string | null>(null);

  const { data: savedKeywordsData, isLoading } = useQuery({
    queryKey: ["savedKeywords", projectId],
    queryFn: () => getSavedKeywords({ data: { projectId } }),
  });
  const savedKeywords = savedKeywordsData?.rows ?? [];

  const removeMutation = useMutation({
    mutationFn: (savedKeywordId: string) =>
      removeSavedKeyword({ data: { savedKeywordId } }),
    onSuccess: () => {
      void queryClient.invalidateQueries({
        queryKey: ["savedKeywords", projectId],
      });
      toast.success("Keyword removed");
    },
    onError: (error) => {
      setRemoveError(getStandardErrorMessage(error, "Remove failed."));
    },
  });

  const handleRemoveKeyword = (savedKeywordId: string) => {
    setRemoveError(null);
    setRemovingId(savedKeywordId);
    removeMutation.mutate(savedKeywordId, {
      onSettled: () => {
        setRemovingId((current) =>
          current === savedKeywordId ? null : current,
        );
      },
    });
  };

  const exportCsv = () => {
    if (savedKeywords.length === 0) {
      toast.error("No keywords to export");
      return;
    }

    const headers = [
      "Keyword",
      "Volume",
      "CPC",
      "Competition",
      "Difficulty",
      "Intent",
      "Fetched At",
    ];
    const csvRows = savedKeywords.map((kw) => [
      kw.keyword,
      kw.searchVolume ?? "",
      kw.cpc?.toFixed(2) ?? "",
      kw.competition?.toFixed(2) ?? "",
      kw.keywordDifficulty ?? "",
      kw.intent ?? "",
      kw.fetchedAt ?? "",
    ]);
    const csv = buildCsv(headers, csvRows);
    downloadCsv("saved-keywords.csv", csv);
  };

  return (
    <SavedKeywordsContent
      isLoading={isLoading}
      removeError={removeError}
      removingId={removingId}
      savedKeywords={savedKeywords}
      onExportCsv={exportCsv}
      onRemoveKeyword={handleRemoveKeyword}
    />
  );
}

function SavedKeywordsContent({
  isLoading,
  removeError,
  removingId,
  savedKeywords,
  onExportCsv,
  onRemoveKeyword,
}: {
  isLoading: boolean;
  removeError: string | null;
  removingId: string | null;
  savedKeywords: Array<{
    id: string;
    keyword: string;
    searchVolume: number | null;
    cpc: number | null;
    competition: number | null;
    keywordDifficulty: number | null;
    intent: string | null;
    fetchedAt: string | null;
  }>;
  onExportCsv: () => void;
  onRemoveKeyword: (savedKeywordId: string) => void;
}) {
  return (
    <div className="px-4 py-4 md:px-6 md:py-6 pb-24 md:pb-8 overflow-auto">
      <div className="mx-auto max-w-5xl space-y-4">
        <div className="flex items-center justify-between">
          <div>
            <h1 className="text-2xl font-semibold">Saved Keywords</h1>
            <p className="text-sm text-base-content/70">
              Keywords you&apos;ve saved from keyword research.
            </p>
          </div>
          {savedKeywords.length > 0 && (
            <button className="btn btn-sm" onClick={onExportCsv}>
              <Download className="size-4" /> Export CSV
            </button>
          )}
        </div>

        {isLoading ? (
          <div className="card bg-base-100 border border-base-300">
            <div className="card-body gap-3" aria-busy>
              <div className="skeleton h-4 w-48" />
              {Array.from({ length: 8 }).map((_, index) => (
                <div
                  key={index}
                  className="grid grid-cols-8 gap-3 items-center"
                >
                  <div className="skeleton h-4 col-span-2" />
                  <div className="skeleton h-4" />
                  <div className="skeleton h-4" />
                  <div className="skeleton h-4" />
                  <div className="skeleton h-4" />
                  <div className="skeleton h-4" />
                  <div className="skeleton h-4" />
                </div>
              ))}
            </div>
          </div>
        ) : savedKeywords.length === 0 ? (
          <div className="card bg-base-100 border border-base-300">
            <div className="card-body text-center py-12 text-base-content/50">
              <Search className="size-8 mx-auto mb-2 opacity-40" />
              <p>
                No saved keywords yet. Use the Keyword Research page to find and
                save keywords.
              </p>
            </div>
          </div>
        ) : (
          <div className="card bg-base-100 border border-base-300">
            <div className="card-body gap-3">
              {removeError ? (
                <div className="rounded-lg border border-error/30 bg-error/10 p-3 text-sm text-error flex items-start gap-2">
                  <AlertCircle className="size-4 shrink-0 mt-0.5" />
                  <span>{removeError}</span>
                </div>
              ) : null}
              <p className="text-sm text-base-content/70">
                {savedKeywords.length} saved keyword
                {savedKeywords.length !== 1 ? "s" : ""}
              </p>
              <SavedKeywordsTable
                rows={savedKeywords}
                removingId={removingId}
                onRemoveKeyword={onRemoveKeyword}
              />
            </div>
          </div>
        )}
      </div>
    </div>
  );
}

function SavedKeywordsTable({
  rows,
  removingId,
  onRemoveKeyword,
}: {
  rows: Array<{
    id: string;
    keyword: string;
    searchVolume: number | null;
    cpc: number | null;
    competition: number | null;
    keywordDifficulty: number | null;
    intent: string | null;
    fetchedAt: string | null;
  }>;
  removingId: string | null;
  onRemoveKeyword: (savedKeywordId: string) => void;
}) {
  return (
    <div className="overflow-x-auto">
      <table className="table table-zebra table-sm">
        <thead>
          <tr>
            <th>Keyword</th>
            <th>Volume</th>
            <th>CPC</th>
            <th>Competition</th>
            <th>Difficulty</th>
            <th>Intent</th>
            <th>Last Fetched</th>
            <th></th>
          </tr>
        </thead>
        <tbody>
          {rows.map((kw) => (
            <tr key={kw.id}>
              <td className="font-medium">{kw.keyword}</td>
              <td>{formatNumber(kw.searchVolume)}</td>
              <td>{kw.cpc == null ? "-" : `$${kw.cpc.toFixed(2)}`}</td>
              <td>
                {kw.competition == null ? "-" : kw.competition.toFixed(2)}
              </td>
              <td>
                <DifficultyBadge value={kw.keywordDifficulty} />
              </td>
              <td>
                <span className="badge badge-sm badge-ghost">
                  {kw.intent ?? "?"}
                </span>
              </td>
              <td className="text-xs text-base-content/50">
                {kw.fetchedAt
                  ? new Date(kw.fetchedAt).toLocaleDateString()
                  : "-"}
              </td>
              <td>
                <button
                  className="btn btn-ghost btn-xs text-error"
                  onClick={() => onRemoveKeyword(kw.id)}
                  disabled={removingId === kw.id}
                  title="Remove"
                >
                  {removingId === kw.id ? (
                    <Loader2 className="size-3 animate-spin" />
                  ) : (
                    <Trash2 className="size-3" />
                  )}
                </button>
              </td>
            </tr>
          ))}
        </tbody>
      </table>
    </div>
  );
}

function DifficultyBadge({ value }: { value: number | null }) {
  if (value == null)
    return <span className="badge badge-ghost badge-sm">-</span>;
  if (value < 30)
    return <span className="badge badge-success badge-sm">{value}</span>;
  if (value <= 60)
    return <span className="badge badge-warning badge-sm">{value}</span>;
  return <span className="badge badge-error badge-sm">{value}</span>;
}

function formatNumber(value: number | null | undefined) {
  if (value == null) return "-";
  return new Intl.NumberFormat().format(value);
}