param(
    [int] $Port = 7788,
    [string] $Log = "$PSScriptRoot\sc_crier.log"
)

function Say($msg) {
    for ($i = 0; $i -lt 5; $i++) {
        try { "$msg" | Out-File -FilePath $Log -Append -Encoding utf8; return }
        catch { Start-Sleep -Milliseconds 100 }
    }
}

"" | Out-File -FilePath $Log -Encoding utf8
Say "[crier-sc] starting on 127.0.0.1:$Port"

$listener = New-Object System.Net.Sockets.TcpListener([System.Net.IPAddress]::Loopback, $Port)
$listener.Server.SetSocketOption('Socket', 'ReuseAddress', $true)
$bound = $false
for ($i = 0; $i -lt 30 -and -not $bound; $i++) {
    try { $listener.Start(); $bound = $true } catch { Start-Sleep -Seconds 1 }
}
if (-not $bound) { Say "[crier-sc] could not bind"; exit 1 }
Say "[crier-sc] listening"

$client = $listener.AcceptTcpClient()
Say "[crier-sc] === shard connected ==="
$stream = $client.GetStream()
$stream.ReadTimeout = 1500
$reader = New-Object System.IO.StreamReader($stream)
$writer = New-Object System.IO.StreamWriter($stream)
$writer.AutoFlush = $true
Start-Sleep -Milliseconds 500

# Blocking read with a timeout, so StreamReader-buffered lines are not missed the way
# checking $stream.DataAvailable does.
function Drain($seconds) {
    $deadline = (Get-Date).AddSeconds($seconds)
    while ((Get-Date) -lt $deadline) {
        try {
            $l = $reader.ReadLine()
            if ($null -ne $l) { Say "[crier-sc] <- $l" }
        } catch { Start-Sleep -Milliseconds 50 }
    }
}

function Send($obj) {
    $writer.WriteLine($obj)
    Say "[crier-sc] -> $obj"
    Drain 1.5
}

# 1. valid add
Send '{"kind":"towncrier.add","id":"n1","lines":["Hear ye, hear ye!","The market tax is now 5 percent."],"durationSec":3600}'
# 2. add exceeding the line cap (default 6) -> error
Send '{"kind":"towncrier.add","id":"n2","lines":["1","2","3","4","5","6","7","8"],"durationSec":60}'
# 3. remove the valid one
Send '{"kind":"towncrier.remove","id":"n1"}'
# 4. remove an unknown id -> error
Send '{"kind":"towncrier.remove","id":"does-not-exist"}'

Drain 3

Say "[crier-sc] done"
$client.Close(); $listener.Stop()