Set-StrictMode -Version 3.0
$ErrorActionPreference = 'Stop'

$script:BellAllowedEnvironment = @(
    'BELL_HOST', 'BELL_PORT', 'BELL_WEB_HOST', 'BELL_WEB_PORT',
    'BELL_DATABASE_URL', 'BELL_JWT_SECRET', 'BELL_BOOTSTRAP_USERNAME',
    'BELL_BOOTSTRAP_PASSWORD', 'BELL_AUTO_MIGRATE',
    'BELL_SYNTHETIC_EVENTS_ENABLED'
)

function Get-BellPackageRoot {
    param([string]$ScriptDirectory = $PSScriptRoot)
    return [IO.Path]::GetFullPath((Join-Path $ScriptDirectory '..\..'))
}
function Import-BellEnvironment {
    param([Parameter(Mandatory = $true)][string]$Path)
    if (-not (Test-Path -LiteralPath $Path -PathType Leaf)) { throw "Bell configuration file not found: $Path" }
    $lineNumber = 0
    foreach ($rawLine in Get-Content -LiteralPath $Path -Encoding UTF8) {
        $lineNumber++
        $line = $rawLine.Trim()
        if ($line.Length -eq 0 -or $line.StartsWith('#')) { continue }
        $separator = $line.IndexOf('=')
        if ($separator -lt 1) { throw "Invalid Bell configuration at line $lineNumber. Expected NAME=value." }
        $name = $line.Substring(0, $separator).Trim()
        if ($script:BellAllowedEnvironment -notcontains $name) { throw "Unsupported Bell configuration key at line ${lineNumber}: $name" }
        $value = $line.Substring($separator + 1)
        if ($value.Length -ge 2) {
            $first, $last = $value[0], $value[$value.Length - 1]
            if (($first -eq '"' -and $last -eq '"') -or ($first -eq "'" -and $last -eq "'")) { $value = $value.Substring(1, $value.Length - 2) }
        }
        if ([string]::IsNullOrWhiteSpace([Environment]::GetEnvironmentVariable($name, 'Process'))) {
            [Environment]::SetEnvironmentVariable($name, $value, 'Process')
        }
    }
}

function Get-BellEnvironmentValue {
    param([Parameter(Mandatory = $true)][string]$Name, [string]$Default = '')
    $value = [Environment]::GetEnvironmentVariable($Name, 'Process')
    if ([string]::IsNullOrWhiteSpace($value)) { return $Default }
    return $value
}

function Test-BellTcpEndpoint {
    param([Parameter(Mandatory = $true)][string]$HostName, [Parameter(Mandatory = $true)][int]$Port, [int]$TimeoutMilliseconds = 2000)
    $client = [Net.Sockets.TcpClient]::new()
    try { return $client.ConnectAsync($HostName, $Port).Wait($TimeoutMilliseconds) -and $client.Connected } catch { return $false } finally { $client.Dispose() }
}

function Test-BellListenPortAvailable {
    param([Parameter(Mandatory = $true)][string]$HostName, [Parameter(Mandatory = $true)][int]$Port)
    $ip = if ($HostName -eq '0.0.0.0') { [Net.IPAddress]::Any } elseif ($HostName -in @('127.0.0.1', 'localhost')) { [Net.IPAddress]::Loopback } else { [Net.IPAddress]::Parse($HostName) }
    $listener = [Net.Sockets.TcpListener]::new($ip, $Port)
    try { $listener.Start(); return $true } catch { return $false } finally { try { $listener.Stop() } catch {} }
}

function Get-BellDatabaseEndpoint {
    param([Parameter(Mandatory = $true)][string]$Connection)
    if ($Connection -match '^postgres(?:ql)?://') {
        $uri = [Uri]$Connection
        return [pscustomobject]@{ Host = $uri.Host; Port = $(if ($uri.IsDefaultPort) { 5432 } else { $uri.Port }); Database = $uri.AbsolutePath.TrimStart('/') }
    }
    $values = @{}
    foreach ($match in [regex]::Matches($Connection, '(?:^|\s)(?<key>[A-Za-z_][A-Za-z0-9_]*)=(?<value>''(?:[^'']|'''')*''|"(?:[^"]|"")*"|[^\s]+)')) {
        $value = $match.Groups['value'].Value.Trim("'", '"')
        $values[$match.Groups['key'].Value.ToLowerInvariant()] = $value
    }
    if ($values.Count -eq 0) { throw 'BELL_DATABASE_URL must be a PostgreSQL URI or keyword connection string.' }
    return [pscustomobject]@{ Host = $(if ($values.host) { $values.host } else { '127.0.0.1' }); Port = $(if ($values.port) { [int]$values.port } else { 5432 }); Database = [string]$values.dbname }
}

function Get-BellPort {
    param([string]$Name, [int]$Default)
    $text = Get-BellEnvironmentValue -Name $Name -Default $Default.ToString()
    $port = 0
    if (-not [int]::TryParse($text, [ref]$port) -or $port -lt 1 -or $port -gt 65535) { throw "$Name must be an integer between 1 and 65535." }
    return $port
}

function Initialize-BellRuntime {
    param([Parameter(Mandatory = $true)][string]$PackageRoot, [switch]$AllowOccupiedPorts)
    Import-BellEnvironment -Path (Join-Path $PackageRoot 'config\bell.env')
    $hostName = Get-BellEnvironmentValue -Name 'BELL_HOST' -Default '127.0.0.1'
    $webHost = Get-BellEnvironmentValue -Name 'BELL_WEB_HOST' -Default '127.0.0.1'
    if ($hostName -notin @('127.0.0.1', 'localhost') -or $webHost -notin @('127.0.0.1', 'localhost')) { throw 'BELL_HOST and BELL_WEB_HOST must be loopback addresses.' }
    $port = Get-BellPort -Name 'BELL_PORT' -Default 18090
    $webPort = Get-BellPort -Name 'BELL_WEB_PORT' -Default 18091
    if ($port -eq $webPort) { throw 'BELL_PORT and BELL_WEB_PORT must be different.' }
    if (-not $AllowOccupiedPorts) {
        if (-not (Test-BellListenPortAvailable -HostName $hostName -Port $port)) { throw "Bell backend port $hostName`:$port is already in use." }
        if (-not (Test-BellListenPortAvailable -HostName $webHost -Port $webPort)) { throw "Bell web port $webHost`:$webPort is already in use." }
    }
    $databaseURL = Get-BellEnvironmentValue -Name 'BELL_DATABASE_URL'
    if ([string]::IsNullOrWhiteSpace($databaseURL)) { throw 'BELL_DATABASE_URL is required.' }
    $database = Get-BellDatabaseEndpoint -Connection $databaseURL
    if ([string]::IsNullOrWhiteSpace($database.Database)) { throw 'BELL_DATABASE_URL must name a database.' }
    if (-not (Test-BellTcpEndpoint -HostName $database.Host -Port $database.Port)) { throw "PostgreSQL is unreachable at $($database.Host):$($database.Port)." }
    $jwt = Get-BellEnvironmentValue -Name 'BELL_JWT_SECRET'
    if ($jwt.Length -lt 32 -or $jwt.StartsWith('__BELL_')) { throw 'BELL_JWT_SECRET must contain at least 32 non-default characters.' }
    $webRoot = Join-Path $PackageRoot 'web'
    if (-not (Test-Path -LiteralPath (Join-Path $webRoot 'index.html') -PathType Leaf)) { throw "Bell web assets are missing: $webRoot" }
    return [pscustomobject]@{
        Host = $hostName; Port = $port; WebHost = $webHost; WebPort = $webPort;
        BackendUrl = "http://$hostName`:$port"; WebUrl = "http://$webHost`:$webPort";
        SettingsPath = (Join-Path $PackageRoot 'config\settings.yml'); WebRoot = $webRoot
    }
}

function Wait-BellHealth {
    param([Parameter(Mandatory = $true)][string]$BaseUrl, [int]$Attempts = 100)
    for ($attempt = 0; $attempt -lt $Attempts; $attempt++) {
        try { $health = Invoke-RestMethod -Uri "$BaseUrl/healthz" -TimeoutSec 2 -NoProxy; if ($health.status -eq 'ok' -and $health.service -eq 'bell') { return } } catch {}
        Start-Sleep -Milliseconds 300
    }
    throw "Bell health check timed out: $BaseUrl/healthz"
}