#Requires -Version 7
<#
.SYNOPSIS
    Starts the Redefined Designs stack locally for testing and review.

.DESCRIPTION
    Brings up a Postgres container, runs migrations, builds and starts the
    backend, and starts the Vite dev server. Safe to run repeatedly: an
    existing container is reused rather than recreated, and processes already
    listening are left alone.

    Logs and process ids go to .local/ at the repository root.

.PARAMETER Fresh
    Drop the database container and its data before starting, so migrations
    run against an empty database.

.PARAMETER Stop
    Stop the backend, the dev server and the database container, then exit.

.PARAMETER DbPort
    Host port for Postgres. Change it if something already holds the default.

.EXAMPLE
    .\scripts\start-local.ps1
    .\scripts\start-local.ps1 -Fresh
    .\scripts\start-local.ps1 -Stop
#>
[CmdletBinding()]
param(
    # Deliberately not 55432. That port is reserved by Hyper-V on at least one
    # machine here, and Docker's failure when it cannot bind does not mention
    # reservations, which has cost time more than once.
    [int]$DbPort = 55500,
    [int]$ApiPort = 3000,
    [int]$WebPort = 5173,
    [switch]$Fresh,
    [switch]$Stop
)

$ErrorActionPreference = 'Stop'

$RepoRoot = Split-Path -Parent $PSScriptRoot
$StateDir = Join-Path $RepoRoot '.local'
$PidFile = Join-Path $StateDir 'pids.json'
$Container = 'redefined-designs-local-db'
$DbUser = 'redefined_local'
$DbPassword = 'redefined_local'
$DbName = 'redefined_local'

function Write-Step { param([string]$Message) Write-Host "==> $Message" -ForegroundColor Cyan }
function Write-Note { param([string]$Message) Write-Host "    $Message" -ForegroundColor DarkGray }
function Write-Good { param([string]$Message) Write-Host "    $Message" -ForegroundColor Green }

# $ErrorActionPreference = 'Stop' does NOT stop the script when a native
# executable exits non-zero, only when a cmdlet throws. Everything here is
# node, npm or docker, so without this wrapper a failed migration is a line of
# red text the script prints and then carries straight past. It did exactly
# that once, and reported a healthy stack sitting on an empty database.
function Invoke-Checked {
    param([scriptblock]$Command, [string]$What)
    & $Command
    if ($LASTEXITCODE -ne 0) {
        throw "$What failed (exit code $LASTEXITCODE)."
    }
}

function Assert-Docker {
    docker info *>$null
    if ($LASTEXITCODE -ne 0) {
        throw "Docker is not running. Start Docker Desktop and try again."
    }
}

# node-pg-migrate pulls in an lru-cache that calls
# diagnostics_channel.tracingChannel, which does not exist before Node 20. On
# Node 18 the migration dies in minified library code with "(0 , U.tracingChannel)
# is not a function", which says nothing about versions. CI runs Node 20.
function Assert-NodeVersion {
    $raw = (node --version)
    $major = [int](($raw -replace '^v', '') -split '\.')[0]
    if ($major -lt 20) {
        throw @"
Node $raw is too old. This needs Node 20 or newer.

If you use nvm-windows:

    nvm use 24.13.1

Then run this script again in a new shell.
"@
    }
    Write-Note "node $raw"
}

# Reads back only the ids this script wrote. Killing by port would be shorter
# and would also kill whatever else happened to be listening.
function Get-TrackedProcesses {
    if (-not (Test-Path $PidFile)) { return @{} }
    try { return (Get-Content $PidFile -Raw | ConvertFrom-Json -AsHashtable) }
    catch { return @{} }
}

function Stop-Tracked {
    param([string]$Name)
    $tracked = Get-TrackedProcesses
    if (-not $tracked.ContainsKey($Name)) { return }
    $process = Get-Process -Id $tracked[$Name] -ErrorAction SilentlyContinue
    if ($process) {
        Stop-Process -Id $process.Id -Force -ErrorAction SilentlyContinue
        Write-Good "stopped $Name (pid $($process.Id))"
    }
}

function Set-Tracked {
    param([string]$Name, [int]$ProcessId)
    $tracked = Get-TrackedProcesses
    $tracked[$Name] = $ProcessId
    $tracked | ConvertTo-Json | Set-Content $PidFile
}

function Test-Listening {
    param([int]$Port)
    return [bool](Get-NetTCPConnection -LocalPort $Port -State Listen -ErrorAction SilentlyContinue)
}

function Wait-For {
    param(
        [scriptblock]$Condition,
        [string]$What,
        [int]$TimeoutSeconds = 60
    )
    for ($i = 1; $i -le $TimeoutSeconds; $i++) {
        if (& $Condition) {
            Write-Good "$What ready after ${i}s"
            return
        }
        Start-Sleep -Seconds 1
    }
    throw "$What did not become ready within ${TimeoutSeconds}s."
}

function Stop-Environment {
    Write-Step 'Stopping'
    Stop-Tracked 'backend'
    Stop-Tracked 'frontend'
    docker stop $Container *>$null
    if ($LASTEXITCODE -eq 0) { Write-Good "stopped container $Container" }
    else { Write-Note "container $Container was not running" }
    Remove-Item $PidFile -ErrorAction SilentlyContinue
    Write-Host ''
    Write-Host 'Stopped.' -ForegroundColor Green
}

function Start-Database {
    if ($Fresh) {
        Write-Step 'Removing the existing database (-Fresh)'
        docker rm -f $Container *>$null
        Write-Good 'removed'
    }

    $existing = (docker ps -a --filter "name=^/$Container$" --format '{{.Names}}')
    if ($existing -eq $Container) {
        Write-Step "Reusing the database container"
        docker start $Container *>$null
    }
    else {
        Write-Step "Creating the database container on port $DbPort"
        docker run -d --name $Container `
            -e "POSTGRES_USER=$DbUser" `
            -e "POSTGRES_PASSWORD=$DbPassword" `
            -e "POSTGRES_DB=$DbName" `
            -p "${DbPort}:5432" `
            postgres:16 *>$null

        if ($LASTEXITCODE -ne 0) {
            # The message Docker gives for a reserved port does not say
            # "reserved", so name the likely cause and the way out of it.
            throw @"
Could not start Postgres on port $DbPort.

If the port is in use, or reserved by Hyper-V (which silently claims ranges on
Windows), pick another one:

    .\scripts\start-local.ps1 -DbPort 55600

Reserved ranges: netsh interface ipv4 show excludedportrange protocol=tcp
"@
        }
    }

    Wait-For -What 'Postgres' -Condition {
        docker exec $Container pg_isready -U $DbUser -d $DbName *>$null
        $LASTEXITCODE -eq 0
    }
}

function Install-IfMissing {
    param([string]$Directory)
    $name = Split-Path -Leaf $Directory
    if (Test-Path (Join-Path $Directory 'node_modules')) {
        Write-Note "$name dependencies already installed"
        return
    }
    Write-Step "Installing $name dependencies"
    Push-Location $Directory
    try { Invoke-Checked { npm install } "$name npm install" } finally { Pop-Location }
}

function Start-Backend {
    $backend = Join-Path $RepoRoot 'backend'

    # The six the backend refuses to boot without, plus the two that make a
    # local run behave. Set in this session so the child process inherits them.
    $env:PGHOST = 'localhost'
    $env:PGPORT = "$DbPort"
    $env:PGUSER = $DbUser
    $env:PGPASSWORD = $DbPassword
    $env:PGDATABASE = $DbName
    $env:UPLOADS_DIR = (Join-Path $StateDir 'uploads')
    $env:PORT = "$ApiPort"
    # No PayPal credentials locally. DEMO_MODE lets the whole cart and checkout
    # path run without them and with no way to reach live PayPal.
    $env:DEMO_MODE = 'true'
    New-Item -ItemType Directory -Force -Path $env:UPLOADS_DIR *>$null

    Write-Step 'Running migrations'
    Push-Location $backend
    try {
        Invoke-Checked { node migrate.js up } 'Migrations'
        Write-Step 'Building the backend'
        Invoke-Checked { npm run build } 'Backend build'
    }
    finally { Pop-Location }

    if (Test-Listening -Port $ApiPort) {
        Write-Note "something is already listening on $ApiPort; leaving it alone"
        return
    }

    Write-Step "Starting the backend on $ApiPort"
    # Separate files: Start-Process cannot redirect both streams to one path.
    $process = Start-Process -FilePath 'node' -ArgumentList 'dist/server.js' `
        -WorkingDirectory $backend `
        -RedirectStandardOutput (Join-Path $StateDir 'backend.log') `
        -RedirectStandardError (Join-Path $StateDir 'backend.err.log') `
        -WindowStyle Hidden -PassThru
    Set-Tracked 'backend' $process.Id

    Wait-For -What 'Backend' -Condition {
        try {
            $null = Invoke-WebRequest "http://localhost:$ApiPort/api/config" -TimeoutSec 2 -UseBasicParsing
            $true
        }
        catch { $false }
    }
}

function Start-Frontend {
    if (Test-Listening -Port $WebPort) {
        Write-Note "something is already listening on $WebPort; leaving it alone"
        return
    }

    Write-Step "Starting the dev server on $WebPort"
    $process = Start-Process -FilePath 'npm.cmd' -ArgumentList 'run', 'dev' `
        -WorkingDirectory (Join-Path $RepoRoot 'frontend') `
        -RedirectStandardOutput (Join-Path $StateDir 'frontend.log') `
        -RedirectStandardError (Join-Path $StateDir 'frontend.err.log') `
        -WindowStyle Hidden -PassThru
    Set-Tracked 'frontend' $process.Id

    Wait-For -What 'Dev server' -Condition { Test-Listening -Port $WebPort }
}

New-Item -ItemType Directory -Force -Path $StateDir *>$null

if ($Stop) {
    Stop-Environment
    return
}

Assert-NodeVersion
Assert-Docker
Start-Database
Install-IfMissing (Join-Path $RepoRoot 'backend')
Install-IfMissing (Join-Path $RepoRoot 'frontend')
Start-Backend
Start-Frontend

Write-Host ''
Write-Host 'Running.' -ForegroundColor Green
Write-Host "  Storefront   http://localhost:$WebPort"
Write-Host "  Admin        http://localhost:$WebPort/admin"
Write-Host "  API          http://localhost:$ApiPort/api/config"
Write-Host "  Postgres     localhost:$DbPort  ($DbUser / $DbPassword / $DbName)"
Write-Host ''
Write-Host "  Logs         $StateDir"
Write-Host "  Stop         .\scripts\start-local.ps1 -Stop"
Write-Host ''