import util from 'util'
import childProcess from 'child_process'
const exec = util.promisify(childProcess.exec)
import {getDarcsDiffsFromPatchText} from '../../helpers.ts'

export const getFileList = async(repoName: string, branchName: string, repoLocation: string) => {
  const command = "darcs show files"

  const result = await exec(`(cd ${repoLocation} && ${command})`)
  const files = result.stdout.split("\n").filter(item => item.length > 0 && item != ".")
  return files
}

export const getBranchInfo = async (repoName: string, branchName: string, repoLocation: string) => {
  const patches = new Map()

  const totalPatchesCountRes = await exec(`(cd ${repoLocation} && darcs log --count)`)
  const totalPatchesCount = parseInt(totalPatchesCountRes.stdout)
  let hunkRegex = RegExp(/^ *hunk /)
  // Get 100 patches at a time and parse those
  for (let i = 1; i <= totalPatchesCount; i = i + 100) {
    let patchesSubsetRes = await exec(`(cd ${repoLocation} && darcs log --index=${i}-${i+100} -v)`)
    let patchesSubset = patchesSubsetRes.stdout.split("\n")
    do {
      const nextPatchStart = patchesSubset.findIndex((line, index) => {
        return (index > 0 && line.startsWith("patch ")) || index === patchesSubset.length - 1
      })
      const isEndOfFile = nextPatchStart === patchesSubset.length - 1
      const currentPatch = patchesSubset.slice(0, isEndOfFile ? nextPatchStart : nextPatchStart - 1)
      patchesSubset = patchesSubset.slice(nextPatchStart)
      const hash = currentPatch[0].replace("patch ", "").trim()
      const author = currentPatch[1].replace("Author: ", "").trim()
      const date = currentPatch[2].replace("Date: ", "").trim()
      const name = currentPatch[3].replace("  * ", "").trim()
      const diffStart = currentPatch.findIndex((line) => {
        return line.match(hunkRegex)
      })
      const description = currentPatch.slice(5, diffStart).map(str => str.replace("  ", "")).join("\n").trim()
      const diffs = getDarcsDiffsFromPatchText(currentPatch.slice(diffStart).map(str => str.trimStart()).join("\n"))
      patches.set(hash, {
        name,
        description,
        author,
        date,
        hash,
        diffs,
      })
    } while (patchesSubset.length > 1)
  }

  return Array.from(patches.values())
}

export const getFileLastTouchInfo = async (repoName: string, branchName: string, filename: string, repoLocation: string) => {
  const command = `darcs annotate --machine-readable ${filename}`
  const res = await exec(`(cd ${repoLocation} && ${command})`)
  const output = res.stdout
  const outputLines = output.split("\n").map((line) => {
    return line.split(' ')[0]
  })

  return outputLines.map((line) => {
    return {sha: line, author: ''}
  })
}