param(
    [ValidateSet('production', 'demo', 'check')]
    [string]$Mode = 'production'
)

$ErrorActionPreference = 'Stop'

function Import-SenseEnvironment {
    param([string]$Path)

    if (-not (Test-Path -LiteralPath $Path -PathType Leaf)) {
        return
    }

    $lineNumber = 0
    foreach ($line in Get-Content -LiteralPath $Path -Encoding UTF8) {
        $lineNumber++
        $trimmed = $line.Trim()
        if ($trimmed.Length -eq 0 -or $trimmed.StartsWith('#')) {
            continue
        }
        if ($line -notmatch '^\s*(SENSE_[A-Z0-9_]+)\s*=(.*)$') {
            throw "config\sense.env line $lineNumber must use SENSE_NAME=value format"
        }

        $name = $Matches[1]
        $value = $Matches[2].Trim()
        if ($value.Length -ge 2) {
            $first = $value[0]
            $last = $value[$value.Length - 1]
            if (($first -eq '"' -and $last -eq '"') -or ($first -eq "'" -and $last -eq "'")) {
                $value = $value.Substring(1, $value.Length - 2)
            }
        }

        $current = [Environment]::GetEnvironmentVariable($name, 'Process')
        if ([string]::IsNullOrEmpty($current)) {
            [Environment]::SetEnvironmentVariable($name, $value, 'Process')
        }
    }
}

function Assert-RequiredEnvironment {
    param([string[]]$Names)

    foreach ($name in $Names) {
        if ([string]::IsNullOrWhiteSpace([Environment]::GetEnvironmentVariable($name, 'Process'))) {
            throw "$name is required in production mode"
        }
    }
}

try {
    $runtimeRoot = Split-Path -Parent $MyInvocation.MyCommand.Path
    Import-SenseEnvironment -Path (Join-Path $runtimeRoot 'config\sense.env')

    [Environment]::SetEnvironmentVariable('SENSE_UI_STATIC_DIR', (Join-Path $runtimeRoot 'ui'), 'Process')
    if ([string]::IsNullOrWhiteSpace($env:SENSE_HTTP_ADDRESS)) {
        $env:SENSE_HTTP_ADDRESS = '127.0.0.1:18080'
    }

    if ($Mode -eq 'demo') {
        $env:SENSE_DATABASE_MODE = 'memory'
        Write-Host "Starting Sense in temporary demo mode at http://$($env:SENSE_HTTP_ADDRESS) ..."
        Write-Host 'Demo data is discarded when the process stops. Do not use this mode in production.'
    } else {
        $env:SENSE_DATABASE_MODE = 'postgres'
        Assert-RequiredEnvironment -Names @(
            'SENSE_DATABASE_URL',
            'SENSE_IDENTITY_SIGNING_KEY',
            'SENSE_BOOTSTRAP_TOKEN',
            'SENSE_CREDENTIAL_KEY'
        )
        if ($Mode -eq 'check') {
            Write-Host 'Sense production configuration check passed.'
            exit 0
        }
        Write-Host "Starting Sense in production mode at $($env:SENSE_HTTP_ADDRESS) ..."
    }

    $server = Join-Path $runtimeRoot 'sense-server.exe'
    if (-not (Test-Path -LiteralPath $server -PathType Leaf)) {
        throw 'sense-server.exe was not found beside the start script'
    }
    & $server
    exit $LASTEXITCODE
} catch {
    Write-Host "[ERROR] $($_.Exception.Message)"
    Write-Host 'See README-WINDOWS.md and config\sense.env.example.'
    exit 1
}