param(
  [string]$Message  = "",
  [switch]$PullOnly,
  [switch]$Verbose
)

if ($Message -eq "" -and -not $PullOnly) {
  $Message = "Update " + (Get-Date -Format "yyyy-MM-dd HH:mm:ss")
}

if (-not $env:HF_TOKEN -or $env:HF_TOKEN.Trim().Length -lt 10) {
  Write-Host "Error: HF_TOKEN not set"
  Write-Host "Set with: [Environment]::SetEnvironmentVariable('HF_TOKEN','YOUR_TOKEN','User')"
  exit 1
}

$repoRoot = git rev-parse --show-toplevel 2>$null
if ($LASTEXITCODE -ne 0) { Write-Host "Error: Not a git repository"; exit 1 }
Set-Location $repoRoot

$hfRemote = git remote get-url huggingface 2>$null
if ($LASTEXITCODE -ne 0) { Write-Host "Error: HuggingFace remote not configured"; exit 1 }

if ($hfRemote -match 'huggingface\.co/spaces/([^/]+)/(.+?)(?:\.git)?$') {
  $hfUser  = $Matches[1]
  $hfSpace = $Matches[2]
} else { Write-Host "Error: Cannot parse HF remote"; exit 1 }

$config = @{ max_file_size_mb = 10; ask_before_upload = $true }
if (Test-Path ".syncconfig") {
  try {
    $configData = Get-Content ".syncconfig" -Raw | ConvertFrom-Json
    $config.max_file_size_mb  = $configData.max_file_size_mb
    $config.ask_before_upload = $configData.ask_before_upload
  } catch {}
}

Write-Host "`n=== 3-Way Date-Priority Sync ===`n"

function Get-RemoteCommit($remote) {
  $commit = git rev-parse "$remote/main" 2>$null
  if ($LASTEXITCODE -eq 0) { return $commit }; return $null
}
function Get-RemoteDate($remote) {
  $date = git log "$remote/main" -1 --format=%ci 2>$null
  if ($LASTEXITCODE -eq 0 -and $date) { return [datetime]$date }
  return [datetime]::MinValue
}
function Get-FileSize($path) {
  if (Test-Path $path) { return (Get-Item $path).Length / 1MB }; return 0
}
function Ask-Upload($fileName, $sizeMB) {
  Write-Host "`n[WARN] Large file: $fileName ($([math]::Round($sizeMB,2)) MB)"
  Write-Host "  1. Yes   - Upload this file"
  Write-Host "  2. No    - Skip this file"
  Write-Host "  3. All   - Upload all large files"
  Write-Host "  4. Skip  - Skip all large files"
  $c = Read-Host "Choice [1-4] (default: 2)"; if ($c -eq "") { $c = "2" }; return $c
}

git add -A
$skipAll = $false; $uploadAll = $false

if ($config.ask_before_upload) {
  $allFiles   = git diff --cached --name-only --diff-filter=ACMR
  $largeFiles = @()
  foreach ($file in $allFiles) {
    if (Test-Path $file) {
      $sizeMB = Get-FileSize $file
      if ($sizeMB -gt $config.max_file_size_mb) { $largeFiles += @{ Path=$file; Size=$sizeMB } }
    }
  }
  if ($largeFiles.Count -gt 0) {
    Write-Host "Found $($largeFiles.Count) large file(s) (>$($config.max_file_size_mb) MB)"
    $filesToSkip = @()
    foreach ($fileInfo in $largeFiles) {
      if ($uploadAll) { continue }
      if ($skipAll)   { $filesToSkip += $fileInfo.Path; continue }
      $c = Ask-Upload $fileInfo.Path $fileInfo.Size
      switch ($c) {
        "1" { continue } "2" { $filesToSkip += $fileInfo.Path }
        "3" { $uploadAll = $true } "4" { $skipAll = $true; $filesToSkip += $fileInfo.Path }
      }
    }
    if ($filesToSkip.Count -gt 0) {
      Write-Host "Skipping $($filesToSkip.Count) file(s):"
      foreach ($f in $filesToSkip) { git reset HEAD $f 2>$null | Out-Null; Write-Host "  - $f" }
    }
  }
}

Write-Host "Fetching from remotes..."
git fetch github 2>$null;      $ghExists = $LASTEXITCODE -eq 0
git fetch huggingface 2>$null; $hfExists = $LASTEXITCODE -eq 0
$isFirstPush = (-not $ghExists -and -not $hfExists)

if (-not $isFirstPush) {
  $localCommit   = git rev-parse HEAD 2>$null
  $ghCommit      = Get-RemoteCommit "github"
  $hfCommit      = Get-RemoteCommit "huggingface"
  $localDate     = git log HEAD -1 --format=%ci 2>$null
  $localDateTime = if ($localDate) { [datetime]$localDate } else { [datetime]::MinValue }
  $ghDate        = Get-RemoteDate "github"
  $hfDate        = Get-RemoteDate "huggingface"

  Write-Host "Last update dates:"
  Write-Host "  Local:       $($localDateTime.ToString('yyyy-MM-dd HH:mm:ss'))"
  if ($ghExists) { Write-Host "  GitHub:      $($ghDate.ToString('yyyy-MM-dd HH:mm:ss'))" }
  if ($hfExists) { Write-Host "  HuggingFace: $($hfDate.ToString('yyyy-MM-dd HH:mm:ss'))" }
  Write-Host ""

  $remotesToMerge = @()
  if ($ghExists -and $ghCommit -and $localCommit -ne $ghCommit) {
    $remotesToMerge += @{ Name="github";      Date=$ghDate; Commit=$ghCommit }
  }
  if ($hfExists -and $hfCommit -and $localCommit -ne $hfCommit) {
    $remotesToMerge += @{ Name="huggingface"; Date=$hfDate; Commit=$hfCommit }
  }
  $remotesToMerge = $remotesToMerge | Sort-Object -Property Date -Descending

  foreach ($remote in $remotesToMerge) {
    $rName = $remote.Name; $rDate = $remote.Date.ToString('yyyy-MM-dd HH:mm:ss')
    Write-Host "Merging from $rName (updated: $rDate)..."
    git diff HEAD --quiet
    if ($LASTEXITCODE -ne 0) { git commit -m "Local changes before $rName merge" 2>$null | Out-Null }
    git merge "$rName/main" --no-edit 2>&1 | Out-Null
    if ($LASTEXITCODE -ne 0) { Write-Host "[WARN] Conflict detected — keeping local version"; git merge --abort 2>$null }
    else { Write-Host "[OK] Merged from $rName" }
    $localCommit = git rev-parse HEAD 2>$null
  }

  $localCommit = git rev-parse HEAD 2>$null
  if ($ghCommit -and $hfCommit -and $localCommit -eq $ghCommit -and $localCommit -eq $hfCommit) {
    Write-Host "[OK] All 3 locations already in sync"
  } elseif ($remotesToMerge.Count -eq 0) { Write-Host "[OK] Already in sync" }
}

if ($PullOnly) { Write-Host "`n[OK] Pull complete`n"; exit 0 }

git diff HEAD --quiet
if ($LASTEXITCODE -ne 0) {
  git commit -m $Message; Write-Host "[OK] Committed: $Message"
} else {
  $localCommit = git rev-parse HEAD 2>$null; $needsPush = $false
  if ($ghExists) { $ghCommit = Get-RemoteCommit "github"; if ($localCommit -ne $ghCommit) { $needsPush = $true } } else { $needsPush = $true }
  if ($hfExists) { $hfCommit = Get-RemoteCommit "huggingface"; if ($localCommit -ne $hfCommit) { $needsPush = $true } } else { $needsPush = $true }
  if (-not $needsPush) { Write-Host "`n[OK] Already up-to-date`n"; exit 0 }
}

Write-Host "`nPushing to remotes..."
git push github main 2>&1 | Out-Null
if ($LASTEXITCODE -eq 0) { Write-Host "[OK] GitHub" }
else {
  git push github main --force 2>&1 | Out-Null
  if ($LASTEXITCODE -eq 0) { Write-Host "[OK] GitHub (forced)" } else { Write-Host "[ERROR] GitHub push failed" }
}

$hfUrl      = "https://${hfUser}:$($env:HF_TOKEN)@huggingface.co/spaces/${hfUser}/${hfSpace}"
$pushOutput = git push $hfUrl main --force 2>&1
if ($Verbose) { Write-Host "Git output: $pushOutput" }
if ($LASTEXITCODE -eq 0) { Write-Host "[OK] HuggingFace" }
else {
  Write-Host "[ERROR] HuggingFace push failed!"
  Write-Host "  $pushOutput"
  Write-Host "  Check: space exists at huggingface.co/spaces/${hfUser}/${hfSpace}"
  Write-Host "  Try:   .\sync.ps1 -Verbose"
  exit 1
}

Write-Host "`n[OK] Sync complete!`n"