[CmdletBinding()]
param(
    [string]$ConfigPath,
    [switch]$ValidateConfigOnly
)

$ErrorActionPreference = "Stop"
$workspaceRoot = Split-Path -Parent $PSScriptRoot
$webDirectory = Join-Path $workspaceRoot "web"

function ConvertFrom-YamlScalar {
    param([string]$Value)

    $value = $Value.Trim()
    if ($value.Length -ge 2) {
        if ($value.StartsWith('"') -and $value.EndsWith('"')) {
            return $value.Substring(1, $value.Length - 2).Replace('\"', '"').Replace('\\', '\')
        }
        if ($value.StartsWith("'") -and $value.EndsWith("'")) {
            return $value.Substring(1, $value.Length - 2).Replace("''", "'")
        }
    }
    return $value
}

function Read-PortConfig {
    param([string]$Path)

    if (-not (Test-Path -LiteralPath $Path -PathType Leaf)) {
        throw "Local configuration file was not found: $Path. Copy config.example.yaml to config.yaml."
    }
    $values = @{}
    $insidePorts = $false
    foreach ($line in Get-Content -LiteralPath $Path) {
        if ($line -match '^\s*(#.*)?$') {
            continue
        }
        if ($line -match '^ports\s*:\s*$') {
            $insidePorts = $true
            continue
        }
        if ($insidePorts -and $line -match '^\S') {
            break
        }
        if ($insidePorts -and $line -match '^\s+(server|web)\s*:\s*(.*?)\s*$') {
            $values[$Matches[1]] = ConvertFrom-YamlScalar $Matches[2]
        }
    }
    foreach ($key in 'server', 'web') {
        $parsedPort = 0
        if (-not $values.ContainsKey($key) -or
            -not [int]::TryParse([string]$values[$key], [ref]$parsedPort) -or
            $parsedPort -lt 1 -or $parsedPort -gt 65535) {
            throw "ports.$key must be an integer between 1 and 65535 in: $Path"
        }
        $values[$key] = $parsedPort
    }
    if ($values.server -eq $values.web) {
        throw "ports.server and ports.web must be different in: $Path"
    }
    return @{ Server = [int]$values.server; Web = [int]$values.web }
}

if ([string]::IsNullOrWhiteSpace($ConfigPath)) {
    $ConfigPath = Join-Path $workspaceRoot "config.yaml"
}
elseif (-not [IO.Path]::IsPathRooted($ConfigPath)) {
    $ConfigPath = Join-Path $workspaceRoot $ConfigPath
}
$ConfigPath = [IO.Path]::GetFullPath($ConfigPath)
$ports = Read-PortConfig $ConfigPath

Write-Host "GoAuto web UI" -ForegroundColor Cyan
Write-Host "Config: $ConfigPath"
Write-Host "Ports: server=$($ports.Server), web=$($ports.Web)"
if ($ValidateConfigOnly) {
    Write-Host "Local port configuration is valid." -ForegroundColor Green
    return
}

$pnpm = Get-Command pnpm.cmd -ErrorAction SilentlyContinue
if (-not $pnpm) {
    throw "pnpm was not found. Install pnpm and try again."
}

Push-Location $webDirectory
try {
    if (-not (Test-Path -LiteralPath "node_modules" -PathType Container)) {
        Write-Host "Installing frontend dependencies..." -ForegroundColor Cyan
        & $pnpm.Source install --frozen-lockfile
        if ($LASTEXITCODE -ne 0) {
            throw "Frontend dependency installation failed."
        }
    }

    $env:VUE_APP_BASE_API = "http://127.0.0.1:$($ports.Server)"
    Write-Host "Starting GoAuto web UI at http://127.0.0.1:$($ports.Web)" -ForegroundColor Green
    & $pnpm.Source exec vite --host 127.0.0.1 --port $ports.Web --strictPort
    if ($LASTEXITCODE -ne 0) {
        throw "Frontend exited with code $LASTEXITCODE."
    }
}
finally {
    Remove-Item Env:VUE_APP_BASE_API -ErrorAction SilentlyContinue
    Pop-Location
}