import { Diagnostic } from '../../types/Diagnostic'
import { FileLintRule } from '../../types/LintRule'
import { LintRuleType } from '../../types/LintRuleType'
import { Severity } from '../../types/Severity'
import { trimComments } from '../../utils/trimComments'
import { getColumnNumber } from '../../utils/getColumnNumber'

const name = 'hasMacroNameInMend'
const description =
  'Enforces the presence of the macro name in each %mend statement.'
const message = '%mend statement has missing or incorrect macro name'
const test = (value: string) => {
  const diagnostics: Diagnostic[] = []

  const lines: string[] = value ? value.split('\n') : []

  const declaredMacros: { name: string; lineNumber: number }[] = []
  let isCommentStarted = false
  lines.forEach((line, lineIndex) => {
    const { statement: trimmedLine, commentStarted } = trimComments(
      line,
      isCommentStarted
    )
    isCommentStarted = commentStarted
    const statements: string[] = trimmedLine ? trimmedLine.split(';') : []

    statements.forEach((statement) => {
      const { statement: trimmedStatement, commentStarted } = trimComments(
        statement,
        isCommentStarted
      )
      isCommentStarted = commentStarted

      if (trimmedStatement.startsWith('%macro ')) {
        const macroName = trimmedStatement
          .slice(7, trimmedStatement.length)
          .trim()
          .split('(')[0]
        if (macroName)
          declaredMacros.push({
            name: macroName,
            lineNumber: lineIndex + 1
          })
      } else if (trimmedStatement.startsWith('%mend')) {
        const declaredMacro = declaredMacros.pop()
        const macroName = trimmedStatement
          .split(' ')
          .filter((s: string) => !!s)[1]

        if (!declaredMacro) {
          diagnostics.push({
            message: `%mend statement is redundant`,
            lineNumber: lineIndex + 1,
            startColumnNumber: getColumnNumber(line, '%mend'),
            endColumnNumber:
              getColumnNumber(line, '%mend') + trimmedStatement.length,
            severity: Severity.Warning
          })
        } else if (!macroName) {
          diagnostics.push({
            message: `%mend statement is missing macro name - ${
              declaredMacro!.name
            }`,
            lineNumber: lineIndex + 1,
            startColumnNumber: getColumnNumber(line, '%mend'),
            endColumnNumber: getColumnNumber(line, '%mend') + 6,
            severity: Severity.Warning
          })
        } else if (macroName !== declaredMacro!.name) {
          diagnostics.push({
            message: `%mend statement has mismatched macro name, it should be '${
              declaredMacro!.name
            }'`,
            lineNumber: lineIndex + 1,
            startColumnNumber: getColumnNumber(line, macroName),
            endColumnNumber:
              getColumnNumber(line, macroName) + macroName.length - 1,
            severity: Severity.Warning
          })
        }
      }
    })
  })

  declaredMacros.forEach((declaredMacro) => {
    diagnostics.push({
      message: `Missing %mend statement for macro - ${declaredMacro.name}`,
      lineNumber: declaredMacro.lineNumber,
      startColumnNumber: 1,
      endColumnNumber: 1,
      severity: Severity.Warning
    })
  })

  return diagnostics
}

/**
 * Lint rule that checks for the presence of macro name in %mend statement.
 */
export const hasMacroNameInMend: FileLintRule = {
  type: LintRuleType.File,
  name,
  description,
  message,
  test
}