# MiroSociety background launcher (Windows / PowerShell, dev mode)
# Prereq: run deploy.ps1 first to install dependencies.
# Frontend: http://localhost:31400  Backend: http://localhost:31401
#
# Usage (PowerShell):   .\start.ps1
# Already-running services will be restarted.

$ErrorActionPreference = 'Stop'

$ScriptDir    = Split-Path -Parent $MyInvocation.MyCommand.Path
$FrontendPort = 31400
$BackendPort  = 31401
$VenvDir      = Join-Path $ScriptDir 'backend\.venv'
$VenvPy       = Join-Path $VenvDir 'Scripts\python.exe'
$BackendDir   = Join-Path $ScriptDir 'backend'
$FrontendDir  = Join-Path $ScriptDir 'frontend'
$RunDir       = Join-Path $ScriptDir '.run'
$BackendPidFile  = Join-Path $RunDir 'backend.pid'
$FrontendPidFile = Join-Path $RunDir 'frontend.pid'
$BackendLog   = Join-Path $ScriptDir 'backend.log'
$FrontendLog  = Join-Path $ScriptDir 'frontend.log'
$BackendLogErr  = Join-Path $ScriptDir 'backend.err.log'
$FrontendLogErr = Join-Path $ScriptDir 'frontend.err.log'

Set-Location $ScriptDir

function Log($msg)  { Write-Host "[start.ps1] $msg" -ForegroundColor Green }
function Warn($msg) { Write-Host "[start.ps1] $msg" -ForegroundColor Yellow }
function Err($msg)  { Write-Host "[start.ps1] $msg" -ForegroundColor Red }

# --- Check dependencies ---
foreach ($cmd in @('npm','node','curl')) {
    if (-not (Get-Command $cmd -ErrorAction SilentlyContinue)) {
        Err "Missing required command: $cmd"
        exit 1
    }
}
if (-not (Test-Path $VenvPy)) {
    Err "Not found: $VenvPy -- please run deploy.ps1 first."
    exit 1
}
try {
    & $VenvPy -c "import uvicorn" 2>$null | Out-Null
    if ($LASTEXITCODE -ne 0) { throw }
} catch {
    Err "uvicorn is missing in venv -- please run deploy.ps1 first."
    exit 1
}
if (-not (Test-Path (Join-Path $FrontendDir 'node_modules'))) {
    Err "Not found: frontend/node_modules -- please run deploy.ps1 first."
    exit 1
}

if (-not (Test-Path $RunDir)) { New-Item -ItemType Directory -Path $RunDir | Out-Null }

# --- Helpers ---
function Get-PidFromFile($file) {
    if (Test-Path $file) { return (Get-Content $file -Raw).Trim() }
    return $null
}

function Stop-PidFile($pidFile, $label) {
    $procId = Get-PidFromFile $pidFile
    if ($procId -and (Get-Process -Id $procId -ErrorAction SilentlyContinue)) {
        try {
            Stop-Process -Id $procId -Force -ErrorAction SilentlyContinue
            Log "$label stopped (pid=$procId)"
        } catch { }
    }
    if (Test-Path $pidFile) { Remove-Item $pidFile -Force }
}

function Free-Port($port) {
    $conns = Get-NetTCPConnection -LocalPort $port -State Listen -ErrorAction SilentlyContinue
    if ($conns) {
        $pids = ($conns | Select-Object -ExpandProperty OwningProcess -Unique)
        Warn "Port $port is occupied (pid: $($pids -join ',' )), killing..."
        foreach ($p in $pids) {
            try { Stop-Process -Id $p -Force -ErrorAction SilentlyContinue } catch { }
        }
        Start-Sleep -Seconds 1
    }
}

# --- Start backend ---
Free-Port $BackendPort
Stop-PidFile $BackendPidFile 'Backend'
Log "Starting backend FastAPI @ :$BackendPort (background)"
if (Test-Path $BackendLog)     { Clear-Content $BackendLog -Force }
if (Test-Path $BackendLogErr)  { Clear-Content $BackendLogErr -Force }

$backendArgs = @(
    '-m','uvicorn','app.main:app',
    '--host','0.0.0.0','--port',"$BackendPort"
)

$backendProc = Start-Process -FilePath $VenvPy `
    -ArgumentList $backendArgs `
    -WorkingDirectory $BackendDir `
    -RedirectStandardOutput $BackendLog `
    -RedirectStandardError  $BackendLogErr `
    -NoNewWindow `
    -PassThru
$backendProc.Id | Out-File -FilePath $BackendPidFile -Encoding ascii -Force

# --- Start frontend ---
Free-Port $FrontendPort
Stop-PidFile $FrontendPidFile 'Frontend'
Log "Starting frontend Vite @ :$FrontendPort (background)"
if (Test-Path $FrontendLog)     { Clear-Content $FrontendLog -Force }
if (Test-Path $FrontendLogErr)  { Clear-Content $FrontendLogErr -Force }

# On Windows, Start-Process cannot launch a `.cmd` shim by bare name.
# Resolve `npx.cmd` -> its underlying `node.exe` and run `node ./node_modules/vite/bin/vite.js`.
$npmCmd    = (Get-Command npm.cmd -ErrorAction SilentlyContinue).Source
if (-not $npmCmd) { Err 'Cannot locate npm.cmd in PATH'; exit 1 }
$nodeExe   = (Get-Command node -ErrorAction SilentlyContinue).Source
$viteEntry = Join-Path $FrontendDir 'node_modules\vite\bin\vite.js'
if (-not (Test-Path $viteEntry)) {
    Err "Not found: $viteEntry -- please run deploy.ps1 first."
    exit 1
}

$frontendProc = Start-Process -FilePath $nodeExe `
    -ArgumentList @($viteEntry) `
    -WorkingDirectory $FrontendDir `
    -RedirectStandardOutput $FrontendLog `
    -RedirectStandardError  $FrontendLogErr `
    -NoNewWindow `
    -PassThru
$frontendProc.Id | Out-File -FilePath $FrontendPidFile -Encoding ascii -Force

# --- Health check ---
Log "Waiting for services..."
function Wait-For($url, $name) {
    for ($i = 0; $i -lt 30; $i++) {
        try {
            $r = curl.exe -sf $url
            if ($LASTEXITCODE -eq 0) {
                Log "$name is up (v) ($url)"
                return $true
            }
        } catch { }
        Start-Sleep -Seconds 1
    }
    Err "$name failed to start in time, check $name.log"
    return $false
}

Wait-For "http://localhost:$BackendPort/health"  'Backend' | Out-Null
Wait-For "http://localhost:$FrontendPort"        'Frontend' | Out-Null

Write-Host ''
Log "All services ready (v)"
Write-Host "  Frontend: http://localhost:$FrontendPort"
Write-Host "  Backend : http://localhost:$BackendPort  (health: /health)"
Write-Host "  Logs    : backend.log / backend.err.log  /  frontend.log / frontend.err.log"