param(
  [string]$RepoUrl = "https://fun-md.com/Fun_MD/devops-skills.git",
  [string]$CodexHome = "$HOME\.codex",
  [switch]$SkipJj,
  [ValidateSet("auto", "winget", "scoop", "cargo")]
  [string]$JjInstallMethod = $(if ($env:JJ_INSTALL_METHOD) { $env:JJ_INSTALL_METHOD } else { "auto" }),
  [ValidateSet("release", "prerelease")]
  [string]$JjChannel = $(if ($env:JJ_CHANNEL) { $env:JJ_CHANNEL } else { "release" })
)

$ErrorActionPreference = "Stop"

$skillName = "gitea-issue-devops-agent"
$targetDir = Join-Path $CodexHome "skills\$skillName"
$tmpRoot = Join-Path $env:TEMP ("devops-skills-" + [Guid]::NewGuid().ToString("N"))
$installJj = $true
if ($SkipJj.IsPresent) {
  $installJj = $false
}
if ($env:INSTALL_JJ -and $env:INSTALL_JJ -eq "0") {
  $installJj = $false
}

function Write-InstallLog {
  param([string]$Message)
  Write-Host "[install] $Message"
}

function Write-InstallWarn {
  param([string]$Message)
  Write-Warning "[install] $Message"
}

function Test-CommandAvailable {
  param([string]$Name)
  return $null -ne (Get-Command $Name -ErrorAction SilentlyContinue)
}

function Show-JjManualHelp {
  Write-InstallWarn "jj was not installed automatically."
  Write-InstallWarn "Manual options:"
  Write-InstallWarn "  - winget install jj-vcs.jj"
  Write-InstallWarn "  - scoop install main/jj"
  if ($JjChannel -eq "prerelease") {
    Write-InstallWarn "  - cargo install --git https://github.com/jj-vcs/jj.git --locked --bin jj jj-cli"
  }
  else {
    Write-InstallWarn "  - cargo install --locked --bin jj jj-cli"
  }
  Write-InstallWarn "After installation, verify with: jj --version"
}

function Install-JjWithWinget {
  if (-not (Test-CommandAvailable winget)) {
    return $false
  }
  if ($JjChannel -ne "release") {
    Write-InstallWarn "winget path skipped because prerelease jj is requested."
    return $false
  }

  Write-InstallLog "attempting jj installation via winget"
  & winget install --id jj-vcs.jj -e --accept-source-agreements --accept-package-agreements
  return $LASTEXITCODE -eq 0
}

function Install-JjWithScoop {
  if (-not (Test-CommandAvailable scoop)) {
    return $false
  }
  if ($JjChannel -ne "release") {
    Write-InstallWarn "scoop path skipped because prerelease jj is requested."
    return $false
  }

  Write-InstallLog "attempting jj installation via scoop"
  & scoop install main/jj
  return $LASTEXITCODE -eq 0
}

function Install-JjWithCargo {
  if (-not (Test-CommandAvailable cargo)) {
    return $false
  }

  Write-InstallLog "attempting jj installation via cargo"
  if ($JjChannel -eq "prerelease") {
    & cargo install --git https://github.com/jj-vcs/jj.git --locked --bin jj jj-cli
  }
  else {
    & cargo install --locked --bin jj jj-cli
  }
  return $LASTEXITCODE -eq 0
}

function Invoke-JjInstall {
  if (-not $installJj) {
    Write-InstallLog "skipping jj installation because INSTALL_JJ=0 or -SkipJj was provided"
    return
  }

  if (Test-CommandAvailable jj) {
    Write-InstallLog "jj already installed: $(& jj --version)"
    return
  }

  $installed = $false
  switch ($JjInstallMethod) {
    "auto" {
      $installed = (Install-JjWithWinget) -or (Install-JjWithScoop) -or (Install-JjWithCargo)
      break
    }
    "winget" {
      $installed = Install-JjWithWinget
      break
    }
    "scoop" {
      $installed = Install-JjWithScoop
      break
    }
    "cargo" {
      $installed = Install-JjWithCargo
      break
    }
  }

  if (-not $installed) {
    Show-JjManualHelp
    return
  }

  if (Test-CommandAvailable jj) {
    Write-InstallLog "jj installation succeeded: $(& jj --version)"
  }
  else {
    Show-JjManualHelp
  }
}

try {
  if (-not (Test-CommandAvailable git)) {
    throw "[install] git is required but not found."
  }

  Write-InstallLog "downloading $skillName from $RepoUrl"
  git clone --depth 1 $RepoUrl $tmpRoot | Out-Null

  $sourceDir = Join-Path $tmpRoot "skills\$skillName"
  if (-not (Test-Path $sourceDir)) {
    throw "[install] skill directory not found in repository."
  }

  New-Item -ItemType Directory -Force (Join-Path $CodexHome "skills") | Out-Null
  if (Test-Path $targetDir) {
    Remove-Item -Recurse -Force $targetDir
  }
  Copy-Item -Path $sourceDir -Destination $targetDir -Recurse -Force

  Write-InstallLog "skill installed"
  Write-InstallLog "installed path: $targetDir"
  Invoke-JjInstall
  Write-InstallLog "done"
}
finally {
  if (Test-Path $tmpRoot) {
    Remove-Item -Recurse -Force $tmpRoot
  }
}