import { useMemo, useState } from 'react'
import PropTypes from 'prop-types'
import CodeMirror from '@uiw/react-codemirror'
import { EditorView, Decoration, ViewPlugin } from '@codemirror/view'
import { StateField } from '@codemirror/state'
import {
  farmControlDark,
  farmControlLight
} from '../../../codemirror/farmControlTheme'
import {
  getCodeLanguageExtension,
  toEditorCode
} from './codeBlockEditorUtils'
import { useThemeContext } from '../context/ThemeContext'
import ScrollBox from './ScrollBox'
import { Button, Modal, Typography, Card } from 'antd'

const { Link } = Typography

const codeBlockEditorLayoutTheme = EditorView.theme({
  '&': {
    height: 'auto !important'
  },
  '.cm-scroller': {
    overflow: 'visible !important'
  },
  '.cm-gutters': {
    position: 'sticky',
    left: '0',
    zIndex: 2
  }
})

function createScrollBoxSyncExtension() {
  return ViewPlugin.fromClass(
    class {
      constructor(view) {
        this.view = view
        this.scrollEl = view.dom.closest('.simplebar-content-wrapper')
        this.syncing = false
        this.onExternalScroll = this.onExternalScroll.bind(this)
        this.onEditorScroll = this.onEditorScroll.bind(this)

        if (this.scrollEl) {
          this.scrollEl.addEventListener('scroll', this.onExternalScroll, {
            passive: true
          })
          view.scrollDOM.addEventListener('scroll', this.onEditorScroll, {
            passive: true
          })
        }
      }

      syncFromExternal() {
        const { view, scrollEl } = this
        if (this.syncing || !scrollEl) return
        this.syncing = true
        view.scrollDOM.scrollTop = scrollEl.scrollTop
        view.scrollDOM.scrollLeft = scrollEl.scrollLeft
        view.scrollDOM.dispatchEvent(new Event('scroll'))
        this.syncing = false
      }

      syncFromEditor() {
        const { view, scrollEl } = this
        if (this.syncing || !scrollEl) return
        this.syncing = true
        scrollEl.scrollTop = view.scrollDOM.scrollTop
        scrollEl.scrollLeft = view.scrollDOM.scrollLeft
        this.syncing = false
      }

      onExternalScroll() {
        this.syncFromExternal()
      }

      onEditorScroll() {
        this.syncFromEditor()
      }

      destroy() {
        if (this.scrollEl) {
          this.scrollEl.removeEventListener('scroll', this.onExternalScroll)
          this.view.scrollDOM.removeEventListener('scroll', this.onEditorScroll)
        }
      }
    }
  )
}

function buildErrorLineDecorations(state, errorLineSet) {
  if (!errorLineSet.size) {
    return Decoration.none
  }

  const decorations = []
  for (let i = 1; i <= state.doc.lines; i++) {
    if (errorLineSet.has(i)) {
      const line = state.doc.line(i)
      decorations.push(
        Decoration.line({ class: 'cm-errorLine' }).range(line.from)
      )
    }
  }
  return Decoration.set(decorations, true)
}

function createErrorLineExtension(errorLines) {
  const errorLineSet = new Set(errorLines)

  return StateField.define({
    create(state) {
      return buildErrorLineDecorations(state, errorLineSet)
    },
    update(decorations, tr) {
      if (tr.docChanged) {
        return buildErrorLineDecorations(tr.state, errorLineSet)
      }
      return decorations.map(tr.changes)
    },
    provide: (f) => EditorView.decorations.from(f)
  })
}

export default function CodeBlockEditor({
  code = '',
  value,
  language = 'javascript',
  style = {},
  className = '',
  readOnly = false,
  onChange = null,
  height = 'auto',
  showLineNumbers = true,
  disabled = false,
  minimal = false,
  autoCompleteObject = null,
  errorLines = []
}) {
  const { isDarkMode } = useThemeContext()
  const [codeMirrorOpen, setCodeMirrorOpen] = useState(false)
  const sourceCode = value !== undefined ? value : code
  const editorCode = toEditorCode(sourceCode, language)

  const languageExtension = useMemo(
    () => getCodeLanguageExtension(language, autoCompleteObject),
    [language, autoCompleteObject]
  )

  const errorLineExtension = useMemo(() => {
    if (!errorLines?.length) {
      return []
    }
    return [createErrorLineExtension(errorLines)]
  }, [errorLines])

  const editorExtensions = useMemo(
    () => [
      languageExtension,
      ...errorLineExtension,
      codeBlockEditorLayoutTheme,
      createScrollBoxSyncExtension()
    ],
    [languageExtension, errorLineExtension]
  )

  const handleOnChange = (value) => {
    if (typeof code == 'object' && language == 'json') {
      onChange(JSON.parse(value))
    } else {
      onChange(value)
    }
  }

  const codeMirror = (
    <div
      style={{
        ...(height !== 'auto' ? { height } : {}),
        minHeight: 0,
        overflow: 'visible',
        ...style
      }}
      className={`code-block-editor h-100 ${className}`.trim()}
    >
      <Card
        style={{
          borderRadius: 0,
          height: '100%',
          overflow: 'visible',
          backgroundColor: 'var(--layout-modal-bg)'
        }}
        styles={{ body: { padding: 0, height: '100%', overflow: 'visible' } }}
      >
        <ScrollBox>
          <CodeMirror
            value={editorCode}
            height='auto'
            theme={isDarkMode ? farmControlDark : farmControlLight}
            extensions={editorExtensions}
            readOnly={readOnly || disabled}
            onChange={handleOnChange}
            basicSetup={{
              lineNumbers: showLineNumbers,
              foldGutter: true,
              dropCursor: false,
              allowMultipleSelections: false,
              indentOnInput: false,
              syntaxHighlighting: true,
              bracketMatching: true,
              closeBrackets: true,
              autocompletion: !readOnly,
              rectangularSelection: false,
              crosshairCursor: false,
              highlightActiveLine: !readOnly,
              highlightSelectionMatches: false,
              closeBracketsKeymap: false,
              searchKeymap: false,
              foldKeymap: false,
              completionKeymap: !readOnly,
              lintKeymap: false
            }}
            style={{
              fontSize: '14px'
            }}
          />
        </ScrollBox>
      </Card>
    </div>
  )

  return (
    <>
      {minimal ? (
        <div
          style={{ maxWidth: '300px' }}
          className='minimal-code-block-editor'
        >
          <Link
            onClick={() => {
              setCodeMirrorOpen(true)
            }}
          >
            <pre>{editorCode.slice(-64).trim()}...</pre>
          </Link>
          <Modal
            closeIcon={false}
            open={codeMirrorOpen}
            width={800}
            footer={
              <Button
                onClick={() => {
                  setCodeMirrorOpen(false)
                }}
              >
                Close
              </Button>
            }
          >
            {codeMirror}
          </Modal>
        </div>
      ) : (
        codeMirror
      )}
    </>
  )
}

CodeBlockEditor.propTypes = {
  code: PropTypes.oneOfType([PropTypes.string, PropTypes.object]),
  value: PropTypes.oneOfType([PropTypes.string, PropTypes.object]),
  language: PropTypes.oneOfType([
    PropTypes.string,
    PropTypes.arrayOf(PropTypes.string)
  ]),
  style: PropTypes.object,
  className: PropTypes.string,
  readOnly: PropTypes.bool,
  onChange: PropTypes.func,
  height: PropTypes.oneOfType([PropTypes.string, PropTypes.number]),
  showLineNumbers: PropTypes.bool,
  disabled: PropTypes.bool,
  minimal: PropTypes.bool,
  autoCompleteObject: PropTypes.oneOfType([PropTypes.object, PropTypes.string]),
  errorLines: PropTypes.arrayOf(PropTypes.number)
}