param(
    [Parameter(Mandatory=$true)][string]$Server,
    [Parameter(Mandatory=$true)][string]$Owner,
    [Parameter(Mandatory=$true)][string]$Repo,
    [Parameter(Mandatory=$true)][string]$Token
)

$ErrorActionPreference = 'Stop'

$headers = @{ Authorization = "token $Token" }

# Get latest release
$latest = Invoke-RestMethod -Headers $headers -Method GET -Uri "$Server/api/v1/repos/$Owner/$Repo/releases/latest"
if (-not $latest -or -not $latest.id) {
    throw "Failed to get latest release"
}
$rid = [string]$latest.id
Write-Host "Operating on release id: $rid"

# Load full release including attachments/assets list
$release = Invoke-RestMethod -Headers $headers -Method GET -Uri "$Server/api/v1/repos/$Owner/$Repo/releases/$rid"
$assets = $release.assets
if (-not $assets) { $assets = $release.attachments }

if ($assets) {
    $groups = $assets | Group-Object -Property name
    foreach ($g in $groups) {
        $sorted = $g.Group | Sort-Object -Property id -Descending
        if ($sorted.Count -gt 1) {
            $keep = $sorted[0]
            foreach ($extra in $sorted[1..($sorted.Count-1)]) {
                if ($null -ne $extra -and $extra.id -ne $keep.id) {
                    $delUrl = "$Server/api/v1/repos/$Owner/$Repo/releases/assets/$($extra.id)"
                    try {
                        Invoke-RestMethod -Headers $headers -Method DELETE -Uri $delUrl | Out-Null
                        Write-Host ("Deleted duplicate asset: " + $extra.name + " (id=" + $extra.id + ")")
                    } catch {
                        Write-Host ("Failed to delete asset id=" + $extra.id + ": " + $_.Exception.Message) -ForegroundColor Red
                    }
                }
            }
        }
    }
} else {
    Write-Host 'No assets found on release.'
}

# Compose release notes with known checksums if they exist locally
$zipShaPath = (Resolve-Path 'dist\lib-privatebin-v0.1.1.3-windows-x64.zip.sha256' -ErrorAction SilentlyContinue)
$dllShaPath = (Resolve-Path 'dist\windows_bin\privatebinapi.dll.sha256' -ErrorAction SilentlyContinue)
$libShaPath = (Resolve-Path 'dist\windows_bin\privatebinapi.lib.sha256' -ErrorAction SilentlyContinue)
$exeShaPath = (Resolve-Path 'dist\windows_bin\example.exe.sha256' -ErrorAction SilentlyContinue)

$lines = @('# Downloadable artifacts', '')
$lines += ("- [lib-privatebin-v0.1.1.3-windows-x64.zip]($Server/$Owner/$Repo/releases/download/$tag/lib-privatebin-v0.1.1.3-windows-x64.zip)")
$lines += ("- [privatebinapi.dll]($Server/$Owner/$Repo/releases/download/$tag/privatebinapi.dll)")
$lines += ("- [privatebinapi.lib]($Server/$Owner/$Repo/releases/download/$tag/privatebinapi.lib)")
$lines += ("- [example.exe]($Server/$Owner/$Repo/releases/download/$tag/example.exe)")
$lines += ''
$lines += '# SHA256 checksums'
if ($zipShaPath) { $lines += ("- [lib-privatebin-v0.1.1.3-windows-x64.zip.sha256]($Server/$Owner/$Repo/releases/download/$tag/lib-privatebin-v0.1.1.3-windows-x64.zip.sha256)") }
if ($dllShaPath) { $lines += ("- [privatebinapi.dll.sha256]($Server/$Owner/$Repo/releases/download/$tag/privatebinapi.dll.sha256)") }
if ($libShaPath) { $lines += ("- [privatebinapi.lib.sha256]($Server/$Owner/$Repo/releases/download/$tag/privatebinapi.lib.sha256)") }
if ($exeShaPath) { $lines += ("- [example.exe.sha256]($Server/$Owner/$Repo/releases/download/$tag/example.exe.sha256)") }

$lines += ''
$lines += '# Changes'
try {
    $changelog = Get-Content -Raw -LiteralPath 'CHANGELOG.md'
    $sections = $changelog -split "\r?\n## "
    $section = $sections | Where-Object { $_ -like 'v0.1.1.3*' } | Select-Object -First 1
    if ($section) {
        $secLines = $section -split "\r?\n"
        if ($secLines[0] -like 'v0.1.1.3*') { $secLines[0] = 'v0.1.1.3' }
        $lines += $secLines
    } else {
        $lines += 'See CHANGELOG.md'
    }
} catch {
    $lines += 'See CHANGELOG.md'
}

$bodyText = ($lines -join "`n")
$payload = @{ body = $bodyText } | ConvertTo-Json -Depth 3

Invoke-RestMethod -Headers (@{ Authorization = ("token " + $Token); 'Content-Type' = 'application/json' }) -Method PATCH -Uri "$Server/api/v1/repos/$Owner/$Repo/releases/$rid" -Body $payload | Out-Null
Write-Host 'Release notes updated.'