/*
 This file is part of GNU Taler
 (C) 2021 Taler Systems S.A.

 GNU Taler is free software; you can redistribute it and/or modify it under the
 terms of the GNU General Public License as published by the Free Software
 Foundation; either version 3, or (at your option) any later version.

 GNU Taler is distributed in the hope that it will be useful, but WITHOUT ANY
 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
 A PARTICULAR PURPOSE.  See the GNU General Public License for more details.

 You should have received a copy of the GNU General Public License along with
 GNU Taler; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
 */

/**
 *
 * @author Sebastian Javier Marchano (sebasjm)
 */
import { h, VNode } from 'preact';
import { useLayoutEffect, useRef, useState } from 'preact/hooks';

const MAX_IMAGE_UPLOAD_SIZE = 1024 * 1024;

export interface FileTypeContent {
  content: string;
  type: string;
  name: string;
}

export interface FileInputProps {
  label: string;
  grabFocus?: boolean;
  disabled?: boolean;
  error?: string;
  placeholder?: string;
  tooltip?: string;
  onChange: (v: FileTypeContent | undefined) => void;
}

export function FileInput(props: FileInputProps): VNode {
  const inputRef = useRef<HTMLInputElement>(null);
  useLayoutEffect(() => {
    if (props.grabFocus) 
      inputRef.current?.focus();
    
  }, [props.grabFocus]);

  const fileInputRef = useRef<HTMLInputElement>(null);
  const [sizeError, setSizeError] = useState(false);
  return (
    <div class="field">
      <label class="label">
        <a class="button" onClick={(e) => fileInputRef.current?.click()}>
          <div class="icon is-small ">
            <i class="mdi mdi-folder" />
          </div>
          <span>
            {props.label}
          </span>
        </a>
        {props.tooltip && (
          <span class="icon has-tooltip-right" data-tooltip={props.tooltip}>
            <i class="mdi mdi-information" />
          </span>
        )}
      </label>
      <div class="control">
        <input
          ref={fileInputRef}
          style={{ display: 'none' }}
          type="file"
          // name={String(name)}
          onChange={(e) => {
            const f: FileList | null = e.currentTarget.files;
            if (!f || f.length != 1) 
              return props.onChange(undefined);
            
            console.log(f)
            if (f[0].size > MAX_IMAGE_UPLOAD_SIZE) {
              setSizeError(true);
              return props.onChange(undefined);
            }
            setSizeError(false);
            return f[0].arrayBuffer().then((b) => {
              const b64 = btoa(
                new Uint8Array(b).reduce(
                  (data, byte) => data + String.fromCharCode(byte),
                  '',
                ),
              );
              return props.onChange({content: `data:${f[0].type};base64,${b64}`, name: f[0].name, type: f[0].type});
            });
          }}
        />
        {props.error && <p class="help is-danger">{props.error}</p>}
        {sizeError && (
          <p class="help is-danger">File should be smaller than 1 MB</p>
        )}
      </div>
    </div>
  );
}
