import std / [
  os,
  osproc,
  hashes,
  strformat
]

proc runCommand*(
  command: string,
  workingDir: string = ""
): (string, int) =
  echo "-> {command} (workingDir: {workingDir})".fmt
  let (output, code) = execCmdEx(
    command=command,
    workingDir=workingDir
  )
  result = (output, code)

proc ensureDir*(path: string) =
  if not dirExists(path):
    createDir(path)

proc readConfigFile*(configPath: string): string =
  if fileExists(configPath):
    result = readFile(configPath)
  else:
    result = ""
    
proc cloneSource*(
  repoURL: string,
  destinationDir: string
) =
  if dirExists(destinationDir):
    echo "Repository already exists at {destinationDir}".fmt
    echo "Pulling..."
    let (output, code) = runCommand(
      command="git pull",
      workingDir=destinationDir
    )
    echo output
  else:
    echo "Cloning from {repoURL}...".fmt
    let (output, code) = runCommand(
      command="git clone {repoURL} {destinationDir}".fmt
    )
    echo output

proc fetchTags*(
  destinationDir: string
) =
  let (output, code) = runCommand(
    command="git fetch --tags --force",
    workingDir=destinationDir
  )
  echo output


proc resolveTag*(
  destinationDir: string,
  pinnedTag: string = ""
): string =
  ## if pinnedTag is defined, we use that;
  ## otherwise we fall back to newest tag
  if pinnedTag.len > 0:
    result = pinnedTag
    let (output, code) = runCommand(
      command="git rev-parse --verify {pinnedTag}".fmt,
      workingDir=destinationDir
    )
    echo output
    if code != 0:
      # if it fails, we try to fetch the tag
      # just in case
      fetchTags(destinationDir)
      let (newOutput, newCode) = runCommand(
        "git rev-parse --verify {pinnedTag}".fmt,
        workingDir=destinationdir
      )
      echo newOutput
      if newCode != 0:
        quit("Pinned tag {pinnedTag} not found in repo at {destDir}.")
  else:
    let (output, code) = runCommand(
      command="git describe --tags --abbrev=0",
      workingDir=destinationDir
    )
    result = output
    if code != 0:
      quit("There seem to be no releases available from this software")

proc computeSHA256*(
  sourceDir: string,
  chosenTag: string
): string =
  let
    tag = if chosenTag.len > 0: tag else: "HEAD"
    command = "git archive --format=tar {tag} | sha256sum".fmt