<#
.SYNOPSIS
    Mirror the upstream SimpleDocReview checkout into ./app.

.DESCRIPTION
    ./app is a vendored copy of upstream, trimmed to what the deployment needs:
    the server (app.py, kept for the Dockerfile escape hatch) and the front end
    (static/) that the Static Space actually serves.

    This script wipes and re-mirrors it, then records the upstream commit in
    UPSTREAM.json so the Space can always be traced back to a revision.

    Anything you edit under ./app is destroyed by the next run. Fix upstream
    instead, then re-sync.

.PARAMETER UpstreamPath
    The local SimpleDocReview checkout. Defaults to C:\dev\SimpleDocReview.

.PARAMETER AllowDirty
    Sync even when the upstream checkout has uncommitted changes. Without this,
    a dirty upstream is an error, because the recorded commit would not describe
    what actually got deployed.

.EXAMPLE
    .\scripts\sync-upstream.ps1
#>
[CmdletBinding()]
param(
    [string] $UpstreamPath = 'C:\dev\SimpleDocReview',
    [switch] $AllowDirty
)

$ErrorActionPreference = 'Stop'

$repoRoot = Split-Path -Parent $PSScriptRoot
$appDir = Join-Path $repoRoot 'app'

# --- Validate upstream -----------------------------------------------------

if (-not (Test-Path -LiteralPath $UpstreamPath -PathType Container)) {
    throw "Upstream path not found: $UpstreamPath"
}

$upstreamAppPy = Join-Path $UpstreamPath 'app.py'
if (-not (Test-Path -LiteralPath $upstreamAppPy -PathType Leaf)) {
    throw "No app.py at $UpstreamPath - is that really the SimpleDocReview checkout?"
}

$appPySource = Get-Content -LiteralPath $upstreamAppPy -Raw
if ($appPySource -notmatch 'server_version\s*=\s*"SimpleDocReview/') {
    throw "app.py at $UpstreamPath does not identify itself as SimpleDocReview."
}

$serverVersion = ([regex]'server_version\s*=\s*"(SimpleDocReview/[^"]+)"').Match($appPySource).Groups[1].Value

# --- Read upstream git provenance -----------------------------------------

$commit = 'unknown'
$branch = 'unknown'
$isDirty = $false
$originUrl = 'unknown'

if (Test-Path -LiteralPath (Join-Path $UpstreamPath '.git')) {
    Push-Location $UpstreamPath
    try {
        $commit = (& git rev-parse HEAD).Trim()
        $branch = (& git rev-parse --abbrev-ref HEAD).Trim()
        $status = & git status --porcelain
        $isDirty = -not [string]::IsNullOrWhiteSpace(($status -join ''))
        try { $originUrl = (& git remote get-url origin).Trim() } catch { $originUrl = 'none' }
    }
    finally { Pop-Location }
}
else {
    Write-Warning "$UpstreamPath is not a git repo - provenance will be recorded as 'unknown'."
}

if ($isDirty -and -not $AllowDirty) {
    throw @"
Upstream checkout has uncommitted changes.

Commit them in $UpstreamPath first so the deployed Space maps to a real revision,
or re-run with -AllowDirty to deploy the working tree as-is.
"@
}

# --- Mirror upstream -> ./app ---------------------------------------------

# Local review data is a user's documents, not source. It must never be copied
# into a repo that gets pushed to a public Space.
$excludeDirs = @(
    (Join-Path $UpstreamPath '.git'),
    (Join-Path $UpstreamPath '.github'),
    (Join-Path $UpstreamPath '.claude'),
    (Join-Path $UpstreamPath '.vscode'),
    (Join-Path $UpstreamPath '.idea'),
    (Join-Path $UpstreamPath 'tests'),
    (Join-Path $UpstreamPath 'docs'),
    (Join-Path $UpstreamPath 'scripts'),
    (Join-Path $UpstreamPath 'data'),
    (Join-Path $UpstreamPath 'uploads'),
    '__pycache__', '.pytest_cache', '.ruff_cache', '.mypy_cache'
)

# Repo-hygiene files the deployment does not read. README.md in particular must
# not land in app/, because the Space card at the repository root is the README
# Hugging Face renders.
$excludeFiles = @(
    'README.md', 'CLAUDE.md', 'CHANGELOG.md',
    '.gitignore', '.gitattributes',
    '*.pyc', '*.log', '.env', '.env.local'
)

Write-Host "Syncing $UpstreamPath -> $appDir" -ForegroundColor Cyan

New-Item -ItemType Directory -Force -Path $appDir | Out-Null

$robocopyArgs = @(
    $UpstreamPath, $appDir,
    '/MIR',          # mirror: also deletes files removed upstream
    '/NFL', '/NDL',  # quiet: no per-file or per-directory listing
    '/NJH', '/NP',
    '/R:2', '/W:1'
) + @('/XD') + $excludeDirs + @('/XF') + $excludeFiles

& robocopy @robocopyArgs | Out-Null

# Robocopy exit codes 0-7 are success (8+ means copy failures).
if ($LASTEXITCODE -ge 8) {
    throw "robocopy failed with exit code $LASTEXITCODE"
}

# --- Sanity-check what landed --------------------------------------------

$required = @('app.py', 'static/index.html', 'static/app.js', 'static/styles.css')
$missing = $required | Where-Object { -not (Test-Path -LiteralPath (Join-Path $appDir $_)) }
if ($missing.Count -gt 0) {
    throw "Sync incomplete - missing from app/: $($missing -join ', ')"
}

# --- Warn if the Dockerfile's entry point no longer fits app.py ----------

# The container calls app.run('0.0.0.0', 7860) positionally, so a change to that
# signature breaks the escape hatch without breaking the static build - exactly
# the kind of drift nobody notices until they need the container.
if ($appPySource -notmatch 'def\s+run\s*\(\s*host[^)]*port') {
    Write-Warning "app.py's run() signature changed. Check the CMD line in Dockerfile still matches."
}

# --- Record provenance ---------------------------------------------------

function Get-Sha256([string] $path) {
    return (Get-FileHash -LiteralPath $path -Algorithm SHA256).Hash.ToLowerInvariant()
}

$upstream = [ordered]@{
    upstreamRepo     = $originUrl
    upstreamPath     = $UpstreamPath
    commit           = $commit
    branch           = $branch
    dirtyWorkingTree = $isDirty
    serverVersion    = $serverVersion
    portedSources    = [ordered]@{
        'app.py'        = Get-Sha256 (Join-Path $appDir 'app.py')
        'static/app.js' = Get-Sha256 (Join-Path $appDir 'static/app.js')
    }
    syncedAtUtc      = (Get-Date).ToUniversalTime().ToString('yyyy-MM-ddTHH:mm:ssZ')
}
# Written without a BOM: Windows PowerShell 5.1's -Encoding utf8 emits one, and
# a BOM breaks strict JSON parsers that may read this file later.
$upstreamJson = ($upstream | ConvertTo-Json -Depth 4) + [Environment]::NewLine
[System.IO.File]::WriteAllText(
    (Join-Path $repoRoot 'UPSTREAM.json'),
    $upstreamJson,
    (New-Object System.Text.UTF8Encoding $false)
)

# --- Summary -------------------------------------------------------------

$shortCommit = if ($commit.Length -ge 7) { $commit.Substring(0, 7) } else { $commit }
Write-Host ''
Write-Host "Synced $serverVersion @ $shortCommit ($branch)" -ForegroundColor Green
if ($isDirty) { Write-Warning 'Synced from a dirty upstream working tree.' }
Write-Host ''

Push-Location $repoRoot
try {
    $changes = & git status --porcelain
    if ([string]::IsNullOrWhiteSpace(($changes -join ''))) {
        Write-Host 'No changes - the Space already matches upstream.' -ForegroundColor Yellow
    }
    else {
        Write-Host 'Pending changes:'
        & git status --short
        Write-Host ''
        Write-Host 'Deploy with: .\scripts\deploy.ps1' -ForegroundColor Cyan
    }
}
finally { Pop-Location }