import { useMutation, useQuery, useQueryClient } from "@tanstack/react-query";
import { useState } from "react";
import { useNavigate } from "react-router";
import { useApi } from "../api/context";
import { errorMessage } from "../state/actions";
import { PLAYER_STATE_KEY } from "../state/player";
import { Button, Sheet } from "../ui";

/** The file a save is shared as: plain text, dated. */
export function saveFile(code: string, now = new Date()): File {
  const day = now.toISOString().slice(0, 10);
  return new File([code], `deadhead-save-${day}.txt`, { type: "text/plain" });
}

/** Shares the file where the device can (the share sheet), otherwise downloads it. */
async function shareFile(file: File): Promise<void> {
  if (navigator.canShare?.({ files: [file] })) {
    await navigator.share({ files: [file], title: "Deadhead save" });
    return;
  }
  const url = URL.createObjectURL(file);
  const link = document.createElement("a");
  link.href = url;
  link.download = file.name;
  link.click();
  URL.revokeObjectURL(url);
}

const codeBox =
  "mt-1 h-28 w-full resize-none rounded-lg border border-space-600 bg-space-950/70 px-3 py-2 font-mono text-xs break-all text-ink-100 focus:border-amber-400 focus:outline-none";

/** "Export save" (decision 0.5.92): the whole company as one code, to copy or share as a file. */
export function ExportSave() {
  const api = useApi();
  const [open, setOpen] = useState(false);
  const [copied, setCopied] = useState(false);
  const exported = useQuery({
    queryKey: ["export-save"],
    queryFn: () => api.call("exportSave", {}),
    enabled: open,
    gcTime: 0,
    staleTime: 0,
  });
  const code = exported.data?.code;

  const close = () => {
    setOpen(false);
    setCopied(false);
  };

  return (
    <>
      <Button variant="secondary" size="sm" onClick={() => setOpen(true)}>
        Export save
      </Button>
      {open && (
        <Sheet titleId="export-title" title="Export save" eyebrow="Your company">
          <p className="mt-3 text-sm text-ink-200">
            This code is your whole company. Keep it somewhere safe, or import it on another device.
          </p>
          {code ? (
            <>
              <textarea readOnly aria-label="Save code" value={code} className={codeBox} />
              <div className="mt-3 flex gap-2">
                <Button
                  block
                  onClick={() => {
                    void navigator.clipboard
                      ?.writeText(code)
                      .then(() => setCopied(true))
                      .catch(() => setCopied(false));
                  }}
                >
                  {copied ? "Copied" : "Copy"}
                </Button>
                <Button
                  variant="secondary"
                  block
                  onClick={() => void shareFile(saveFile(code)).catch(() => undefined)}
                >
                  Share as file
                </Button>
              </div>
            </>
          ) : exported.isError ? (
            <p role="alert" className="mt-3 text-sm text-rose-300">
              {errorMessage(exported.error)}
            </p>
          ) : (
            <p className="mt-3 text-sm text-ink-400">Packing up your company…</p>
          )}
          <Button variant="secondary" block className="mt-3" onClick={close}>
            Done
          </Button>
        </Sheet>
      )}
    </>
  );
}

/**
 * "Import save": paste a code or open a file, then confirm. `hasCompany`
 * warns that the company on this device is replaced.
 */
export function ImportSave({ hasCompany }: { hasCompany: boolean }) {
  const api = useApi();
  const queryClient = useQueryClient();
  const navigate = useNavigate();
  const [open, setOpen] = useState(false);
  const [code, setCode] = useState("");
  const [confirming, setConfirming] = useState(false);
  const importSave = useMutation({
    mutationFn: () => api.call("importSave", { code }),
    onSuccess: async ({ state }) => {
      queryClient.setQueryData(PLAYER_STATE_KEY, state);
      await queryClient.invalidateQueries();
      close();
      void navigate("/");
    },
    onError: () => setConfirming(false),
  });

  const close = () => {
    setOpen(false);
    setCode("");
    setConfirming(false);
    importSave.reset();
  };

  return (
    <>
      <Button variant="secondary" size="sm" onClick={() => setOpen(true)}>
        Import save
      </Button>
      {open && (
        <Sheet titleId="import-title" title="Import save" eyebrow="Save code" layer="z-30">
          {hasCompany && (
            <p
              role="note"
              className="mt-3 rounded-lg bg-amber-950/50 p-2 text-sm text-amber-200 ring-1 ring-amber-400/40"
            >
              This replaces the company on this device. Export it first if you want to keep it.
            </p>
          )}
          <form
            className="mt-3 space-y-3"
            onSubmit={(e) => {
              e.preventDefault();
              if (!code.trim()) return;
              if (confirming) importSave.mutate();
              else setConfirming(true);
            }}
          >
            <label className="block text-sm">
              <span className="text-ink-300">Paste a save code</span>
              <textarea
                value={code}
                onChange={(e) => {
                  setCode(e.target.value);
                  setConfirming(false);
                }}
                autoComplete="off"
                spellCheck={false}
                className={codeBox}
              />
            </label>
            <label className="block text-sm">
              <span className="text-ink-300">…or open a save file</span>
              <input
                type="file"
                accept=".txt,text/plain"
                onChange={(e) => {
                  const file = e.target.files?.[0];
                  if (file) {
                    void file.text().then((text) => {
                      setCode(text.trim());
                      setConfirming(false);
                    });
                  }
                }}
                className="mt-1 block w-full text-xs text-ink-300 file:mr-3 file:rounded-lg file:border-0 file:bg-space-700 file:px-3 file:py-1.5 file:text-ink-100"
              />
            </label>
            {importSave.isError && (
              <p role="alert" className="text-sm text-rose-300">
                {errorMessage(importSave.error)}
              </p>
            )}
            {confirming && (
              <p className="text-sm text-amber-200">
                {hasCompany ? "Replace your company with this save?" : "Open this company?"}
              </p>
            )}
            <div className="flex gap-2">
              <Button type="submit" block disabled={!code.trim() || importSave.isPending}>
                {confirming ? (hasCompany ? "Replace company" : "Open company") : "Import"}
              </Button>
              <Button variant="secondary" block onClick={close}>
                Cancel
              </Button>
            </div>
          </form>
        </Sheet>
      )}
    </>
  );
}