import { useMemo, useState } from 'react'
import PropTypes from 'prop-types'
import { Button, Modal, Typography, theme, Flex } from 'antd'
import { presentableDiff } from '@codemirror/merge'
import CodeDiffViewer from './CodeDiffViewer'
import { toEditorCode } from './codeBlockEditorUtils'

const { Link, Text } = Typography

const SQUARE_COUNT = 10

const countLines = (str) => {
  if (!str) return 0
  const parts = str.split('\n')
  if (parts[parts.length - 1] === '') parts.pop()
  return Math.max(parts.length, 1)
}

export function getCodeDiffStats(oldCode, newCode, language = 'javascript') {
  const oldText = toEditorCode(oldCode, language)
  const newText = toEditorCode(newCode, language)
  const changes = presentableDiff(oldText, newText)
  let additions = 0
  let deletions = 0

  for (const change of changes) {
    const deleted = oldText.slice(change.fromA, change.toA)
    const added = newText.slice(change.fromB, change.toB)
    if (deleted) deletions += countLines(deleted)
    if (added) additions += countLines(added)
  }

  return { additions, deletions }
}

export default function DiffLabel({
  oldCode = '',
  newCode = '',
  language = 'javascript'
}) {
  const { token } = theme.useToken()
  const [open, setOpen] = useState(false)
  const [viewerReady, setViewerReady] = useState(false)
  const { additions, deletions } = useMemo(
    () => getCodeDiffStats(oldCode, newCode, language),
    [oldCode, newCode, language]
  )

  const greenCount = Math.round(
    (additions / (additions + deletions)) * SQUARE_COUNT
  )

  return (
    <>
      <Link
        className='diff-label'
        onClick={() => {
          setOpen(true)
        }}
      >
        <Flex gap='small' align='center' style={{ marginTop: 0.5 }}>
          <Text style={{ color: token.colorSuccess }}>+{additions}</Text>
          <Flex gap='4px' align='center' style={{ marginBottom: 2 }}>
            {Array.from({ length: SQUARE_COUNT }).map((_, i) => (
              <div
                key={i}
                className='diff-label-square'
                style={{
                  backgroundColor:
                    i < greenCount ? token.colorSuccess : token.colorError
                }}
              />
            ))}
          </Flex>
          <Text style={{ color: token.colorError }}>-{deletions}</Text>
        </Flex>
      </Link>
      <Modal
        closeIcon={false}
        open={open}
        width='90%'
        destroyOnClose
        afterOpenChange={setViewerReady}
        onCancel={() => {
          setOpen(false)
        }}
        footer={
          <Button
            onClick={() => {
              setOpen(false)
            }}
          >
            Close
          </Button>
        }
      >
        {viewerReady ? (
          <CodeDiffViewer
            oldCode={oldCode}
            newCode={newCode}
            language={language}
          />
        ) : null}
      </Modal>
    </>
  )
}

DiffLabel.propTypes = {
  oldCode: PropTypes.oneOfType([PropTypes.string, PropTypes.object]),
  newCode: PropTypes.oneOfType([PropTypes.string, PropTypes.object]),
  language: PropTypes.oneOfType([
    PropTypes.string,
    PropTypes.arrayOf(PropTypes.string)
  ])
}