import { Text, useTheme, useToasts } from '@geist-ui/core'
import { memo } from 'react'
import { useDropzone } from 'react-dropzone'
import styles from './drag-and-drop.module.css'
import type { Document } from '@lib/types'
import generateUUID from '@lib/generate-uuid'
import { allowedFileTypes, allowedFileNames, allowedFileExtensions } from '@lib/constants'


function FileDropzone({ setDocs }: { setDocs: ((docs: Document[]) => void) }) {
    const { palette } = useTheme()
    const { setToast } = useToasts()
    const onDrop = async (acceptedFiles: File[]) => {
        const newDocs = await Promise.all(acceptedFiles.map((file) => {
            return new Promise<Document>((resolve) => {
                const reader = new FileReader()

                reader.onabort = () => setToast({ text: 'File reading was aborted', type: 'error' })
                reader.onerror = () => setToast({ text: 'File reading failed', type: 'error' })
                reader.onload = () => {
                    const content = reader.result as string
                    resolve({
                        title: file.name,
                        content,
                        id: generateUUID()
                    })
                }
                reader.readAsText(file)
            })
        }))

        setDocs(newDocs)
    }

    const validator = (file: File) => {
        const byteToMB = (bytes: number) => Math.round(bytes / 1024 / 1024 * 100) / 100

        // TODO: make this configurable
        const maxFileSize = 50000000;
        if (file.size > maxFileSize) {
            return {
                code: 'file-too-big',
                message: 'File is too big. Maximum file size is ' + byteToMB(maxFileSize) + ' MB.',
            }
        }

        // We initially try to use the browser provided mime type, and then fall back to file names and finally extensions
        if (allowedFileTypes.includes(file.type) || allowedFileNames.includes(file.name) || allowedFileExtensions.includes(file.name?.split('.').pop() || '')) {
            return null
        } else {
            return {
                code: "not-plain-text",
                message: `Only plain text files are allowed.`
            };
        }
    }

    const { getRootProps, getInputProps, isDragActive, fileRejections } = useDropzone({ onDrop, validator })

    const fileRejectionItems = fileRejections.map(({ file, errors }) => (
        <li key={file.name}>
            {file.name}:
            <ul>
                {errors.map(e => (
                    <li key={e.code}><Text>{e.message}</Text></li>
                ))}
            </ul>
        </li>
    ));

    return (
        <div className={styles.container}>
            <div {...getRootProps()} className={styles.dropzone} style={{
                borderColor: palette.accents_3,
            }}>
                <input {...getInputProps()} />
                {!isDragActive && <Text p>Drag some files here, or click to select files</Text>}
                {isDragActive && <Text p>Release to drop the files here</Text>}
            </div>
            {fileRejections.length > 0 && <ul className={styles.error}>
                {/* <Button style={{ float: 'right' }} type="abort" onClick={() => fileRejections.splice(0, fileRejections.length)} auto iconRight={<XCircle />}></Button> */}
                <Text h5>There was a problem with one or more of your files.</Text>
                {fileRejectionItems}
            </ul>}
        </div>
    )
}

export default memo(FileDropzone)