param(
  [Parameter(Position = 0)]
  [string]$Target = "hott-online.pdf",
  [switch]$All,
  [switch]$Clean,
  [switch]$DryRun
)

$ErrorActionPreference = "Stop"

function HasCommand([string]$Name) {
  return [bool](Get-Command $Name -ErrorAction SilentlyContinue)
}

function RunStep([string]$Cmd) {
  if ($DryRun) {
    Write-Output $Cmd
    return
  }
  & powershell.exe -NoProfile -ExecutionPolicy Bypass -Command $Cmd
  if ($LASTEXITCODE -ne $null -and $LASTEXITCODE -ne 0) {
    exit $LASTEXITCODE
  }
}

function Ensure-VersionTex {
  $ver = "local"
  if (HasCommand "git") {
    try {
      $ver = (git describe --always --long).Trim()
    } catch {
      $ver = "local"
    }
  }
  $line = "\newcommand{\OPTversion}{$ver}"
  if ($DryRun) {
    Write-Output ('Set-Content -Encoding ascii -Path version.tex -Value "{0}"' -f $line.Replace('"','`"'))
    return
  }
  Set-Content -Encoding ascii -Path version.tex -Value $line
}

function LatexmkPdf([string]$TexFile) {
  RunStep ('latexmk -interaction=batchmode -g -pdf "{0}"' -f $TexFile)
}

function LatexmkDvi([string]$TexFile) {
  RunStep ('latexmk -interaction=batchmode -dvi "{0}"' -f $TexFile)
}

function PdflatexCycle([string]$TexFile) {
  $base = [System.IO.Path]::GetFileNameWithoutExtension($TexFile)
  RunStep ('pdflatex -halt-on-error -interaction=batchmode "{0}" *> $null' -f $TexFile)
  RunStep ('bibtex "{0}"' -f $base)
  RunStep ('makeindex "{0}"' -f $base)
  RunStep ('pdflatex -halt-on-error -interaction=batchmode "{0}" *> $null' -f $TexFile)
  RunStep ('pdflatex -halt-on-error "{0}"' -f $TexFile)
}

function LatexCycle([string]$TexFile) {
  $base = [System.IO.Path]::GetFileNameWithoutExtension($TexFile)
  RunStep ('latex -halt-on-error -interaction=batchmode "{0}" *> $null' -f $TexFile)
  RunStep ('bibtex "{0}"' -f $base)
  RunStep ('makeindex "{0}"' -f $base)
  RunStep ('latex -halt-on-error -interaction=batchmode "{0}" *> $null' -f $TexFile)
  RunStep ('latex -halt-on-error "{0}"' -f $TexFile)
}

function Compile([string]$TargetFile) {
  Ensure-VersionTex

  $ext = [System.IO.Path]::GetExtension($TargetFile)
  $name = [System.IO.Path]::GetFileNameWithoutExtension($TargetFile)
  $tex = "$name.tex"

  if (-not (Test-Path $tex)) {
    throw "Missing tex file: $tex"
  }

  if ($ext -ieq ".pdf") {
    if (HasCommand "latexmk") {
      LatexmkPdf $tex
    } else {
      PdflatexCycle $tex
    }
    return
  }

  if ($ext -ieq ".dvi") {
    if (HasCommand "latexmk") {
      LatexmkDvi $tex
    } else {
      LatexCycle $tex
    }
    return
  }

  throw "Unsupported target: $TargetFile"
}

function LogCheck {
  if (-not (Test-Path "hott-online.ilg")) {
    return
  }
  $hit = Select-String -Path "hott-online.ilg" -SimpleMatch "!! Input index error" -ErrorAction SilentlyContinue
  if ($hit) {
    throw "Indexing error detected in hott-online.ilg"
  }
}

function CleanFiles {
  $exts = @("out","log","pdf","dvi","fls","fdb_latexmk","aux","brf","bbl","idx","ilg","ind","toc","sed")
  Remove-Item -Force -ErrorAction SilentlyContinue "*~"
  Remove-Item -Force -ErrorAction SilentlyContinue "*.aux"
  foreach ($e in $exts) {
    Remove-Item -Force -ErrorAction SilentlyContinue ("exercise_solutions.{0}" -f $e)
    Remove-Item -Force -ErrorAction SilentlyContinue ("errata.{0}" -f $e)
    Remove-Item -Force -ErrorAction SilentlyContinue ("hott-*.{0}" -f $e)
  }
  if (HasCommand "latexmk") {
    RunStep 'latexmk -interaction=batchmode -C hott-*.tex'
  }
}

$targets = @(
  "hott-online.pdf",
  "hott-bilingual.pdf",
  "hott-ustrade.pdf",
  "hott-letter.pdf",
  "hott-letter-exercises.pdf",
  "hott-a4.pdf",
  "hott-a4-exercises.pdf",
  "hott-ebook.pdf",
  "hott-ebook-wide.pdf",
  "hott-ebook-narrow.pdf",
  "hott-arxiv.pdf",
  "exercise_solutions.pdf",
  "errata.pdf",
  "cover-lulu-hardcover.pdf",
  "cover-lulu-paperback.pdf",
  "cover-letter.pdf",
  "cover-a4.pdf"
)

if ($Clean) {
  CleanFiles
  exit 0
}

if ($All) {
  foreach ($t in $targets) {
    Compile $t
  }
  LogCheck
  exit 0
}

Compile $Target
if ($Target -ieq "hott-online.pdf") {
  LogCheck
}