# Latchpoint — Perforce change-commit trigger (Windows Helix Core servers)
#
# Install:
#   1. Copy to the Perforce server, e.g. C:\p4\latchpoint-trigger.ps1
#   2. Set for the account running p4d:
#        LATCHPOINT_URL=<endpoint from the Jira admin page>
#        LATCHPOINT_SECRET=<secret from the Jira admin page>
#        LATCHPOINT_SWARM_URL=<optional, e.g. https://swarm.example.com>
#   3. p4 triggers
#        latchpoint change-commit //... "powershell -NoProfile -ExecutionPolicy Bypass -File C:\p4\latchpoint-trigger.ps1 %change% %user%"
#
#      -ExecutionPolicy Bypass is REQUIRED, not defensive. Windows Server defaults to
#      RemoteSigned, which refuses to run any script downloaded from the internet — this
#      one included. Without it PowerShell exits 1 before the script starts, and Perforce
#      reads that as a failed trigger. Admins who prefer not to pass Bypass can instead run
#      `Unblock-File C:\p4\latchpoint-trigger.ps1` once, after reviewing the source.
#
# Design rule: this script MUST NOT be able to block or delay a submit. Every path
# exits 0, nothing prompts, and no unhandled error can escape. A version-control
# server is not a place to be clever.
#
# Runs under Windows PowerShell 5.1 (what `powershell -File` invokes) and PowerShell 7+.

# NOT Mandatory: a mandatory parameter with an empty value prompts for input, and a
# trigger has no console — it would hang until p4d's timeout instead of failing fast.
param(
  [string]$Change = '',
  [string]$User = ''
)

# 'Stop' is actively dangerous here. Under Windows PowerShell 5.1, a native command
# writing ANY stderr while its output is redirected raises NativeCommandError; with
# 'Stop' that terminates the script with exit code 1 and the submit is reported failed.
$ErrorActionPreference = 'Continue'
$PSNativeCommandUseErrorActionPreference = $false
$ProgressPreference = 'SilentlyContinue'

function Get-Payload {
  param([string]$Change, [string]$User)

  $url    = $env:LATCHPOINT_URL
  $secret = $env:LATCHPOINT_SECRET
  $p4     = if ($env:P4_EXE)   { $env:P4_EXE }   else { 'p4' }
  $depot  = if ($env:LATCHPOINT_DEPOT) { $env:LATCHPOINT_DEPOT } else { 'depot' }
  $swarm  = $env:LATCHPOINT_SWARM_URL

  if (-not $Change) { return @{ Skip = 'no changelist number supplied' } }
  if (-not $url)    { return @{ Skip = 'LATCHPOINT_URL not set' } }
  if (-not $secret) { return @{ Skip = 'LATCHPOINT_SECRET not set' } }

  # 2>$null discards stderr rather than merging it into the output stream, which is
  # what makes NativeCommandError possible in the first place.
  $raw = & $p4 -ztag describe -s $Change 2>$null
  if ($LASTEXITCODE -ne 0) { return @{ Skip = 'p4 describe failed' } }

  $fields = @{}
  $fileCount = 0
  foreach ($line in $raw) {
    if ("$line" -match '^\.\.\.\s+(\S+)\s*(.*)$') {
      $k = $matches[1]; $v = $matches[2]
      if ($k -match '^depotFile') { $fileCount++ }
      elseif (-not $fields.ContainsKey($k)) { $fields[$k] = $v }
    }
  }

  $desc = $fields['desc']
  if (-not $desc) { return @{ Skip = 'empty description' } }

  # Cheap local guard: no Jira key, no network call.
  if ($desc -notmatch '\b[A-Z][A-Z0-9]+-\d+\b') {
    return @{ Skip = 'no Jira issue key in description' }
  }

  $epoch = 0
  [void][int]::TryParse("$($fields['time'])", [ref]$epoch)
  $iso = if ($epoch -gt 0) {
    [DateTimeOffset]::FromUnixTimeSeconds($epoch).UtcDateTime.ToString('yyyy-MM-ddTHH:mm:ssZ')
  } else {
    (Get-Date).ToUniversalTime().ToString('yyyy-MM-ddTHH:mm:ssZ')
  }

  # File PATHS are deliberately not sent — only how many. See latchpoint.app/perforce.
  $body = @{
    depot       = $depot
    changelists = @(@{
      change      = if ($fields['change']) { $fields['change'] } else { $Change }
      description = $desc
      user        = if ($User) { $User } else { $fields['user'] }
      time        = $iso
      fileCount   = $fileCount
    })
  }
  if ($swarm) { $body['serverUrl'] = $swarm.TrimEnd('/') }

  return @{ Url = $url; Secret = $secret; Json = ($body | ConvertTo-Json -Depth 6 -Compress) }
}

function Publish {
  param([string]$Change, [string]$User)

  $p = Get-Payload -Change $Change -User $User
  if ($p.Skip) { return "Latchpoint: $($p.Skip); skipping." }

  # Windows Server images often still negotiate TLS 1.0 by default, which Atlassian rejects.
  try {
    [Net.ServicePointManager]::SecurityProtocol =
      [Net.ServicePointManager]::SecurityProtocol -bor [Net.SecurityProtocolType]::Tls12
  } catch { }

  # Encode explicitly so non-ASCII changelist descriptions survive the round trip.
  $bytes = [Text.Encoding]::UTF8.GetBytes($p.Json)

  try {
    $resp = Invoke-WebRequest -Uri $p.Url -Method Post -Body $bytes `
              -ContentType 'application/json; charset=utf-8' `
              -Headers @{ 'X-Latchpoint-Secret' = $p.Secret } `
              -TimeoutSec 20 -UseBasicParsing
  } catch {
    $code = try { [int]$_.Exception.Response.StatusCode } catch { 0 }
    $why  = if ($code) { "HTTP $code" } else { $_.Exception.Message }
    return "Latchpoint: publish failed ($why); submit unaffected."
  }

  if ($resp.StatusCode -ne 200) {
    return "Latchpoint: publish failed (HTTP $($resp.StatusCode)); submit unaffected."
  }

  $published = try { (ConvertFrom-Json $resp.Content).published } catch { $null }
  if ($null -ne $published -and $published -eq 0) {
    return "Latchpoint: changelist $Change accepted, nothing published (no matching Jira issue)."
  }
  return "Latchpoint: published changelist $Change."
}

try {
  $message = Publish -Change $Change -User $User
} catch {
  $message = "Latchpoint: unexpected error ($($_.Exception.Message)); submit unaffected."
}

Write-Output $message
exit 0