[CmdletBinding()]
param(
    [ValidateSet('combined')]
    [string]$Profile = 'combined',
    [string]$Configuration = 'rev_d',
    [string]$RepositoryRoot = '',
    [string]$IarBuild = ''
)

$ErrorActionPreference = 'Stop'
$repositoryCandidate = if ($RepositoryRoot) {
    $RepositoryRoot
} else {
    Join-Path $PSScriptRoot '..'
}
$resolvedRepository = (Resolve-Path -LiteralPath $repositoryCandidate).Path
$firmwareRoot = Join-Path $resolvedRepository 'firmware\t2g'
$repositoryFirmware = Join-Path $firmwareRoot 'Seat_Controller_demo'
$repositoryProject = Join-Path $repositoryFirmware 'IAR\Seat_Controller_demo.ewp'
$vendorCommon = Join-Path $firmwareRoot 'common'
$vendorDevice = Join-Path $firmwareRoot 'tviibh8m'

function Resolve-IarBuild {
    param([string]$ConfiguredPath)

    $candidates = @()
    if ($ConfiguredPath) {
        $candidates += $ConfiguredPath
    }
    if ($env:COGNITIVE_AGENT_IAR_BUILD) {
        $candidates += $env:COGNITIVE_AGENT_IAR_BUILD
    }
    $command = Get-Command iarbuild.exe -ErrorAction SilentlyContinue
    if ($command) {
        $candidates += $command.Source
    }
    $candidates += @(
        'D:\Program Files\IAR Systems\Embedded Workbench 9.2\common\bin\iarbuild.exe',
        'C:\Program Files\IAR Systems\Embedded Workbench 9.2\common\bin\iarbuild.exe'
    )
    foreach ($candidate in $candidates) {
        if ($candidate -and (Test-Path -LiteralPath $candidate -PathType Leaf)) {
            return (Resolve-Path -LiteralPath $candidate).Path
        }
    }
    throw 'IAR iarbuild.exe was not found; pass -IarBuild or set COGNITIVE_AGENT_IAR_BUILD.'
}

foreach ($required in @($repositoryProject, $vendorCommon, $vendorDevice)) {
    if (-not (Test-Path -LiteralPath $required)) {
        throw "Self-contained firmware dependency is missing: $required"
    }
}
$resolvedIarBuild = Resolve-IarBuild -ConfiguredPath $IarBuild

function Invoke-IarBuild {
    param([string]$ProjectPath)

    Write-Host "Building Seat_Controller_demo ($Configuration)..."
    & $resolvedIarBuild $ProjectPath -build $Configuration -log all
    if ($LASTEXITCODE -ne 0) {
        throw "IAR build failed with exit code $LASTEXITCODE"
    }
}

function Write-ImageSummary {
    param([string]$ImagePath)

    if (-not (Test-Path -LiteralPath $ImagePath -PathType Leaf)) {
        throw "Build completed but HEX image was not found: $ImagePath"
    }
    $hash = Get-FileHash -LiteralPath $ImagePath -Algorithm SHA256
    Write-Host "Seat_Controller_demo HEX: $ImagePath"
    Write-Host "Seat_Controller_demo SHA256: $($hash.Hash.ToLowerInvariant())"
}

# Preserve the IAR project's original ../../common and ../../tviibh8m layout
# while keeping both vendor trees inside this repository.  Building in a
# temporary staging root avoids committing IAR Obj/BrowseInfo/List products.
$temporaryParent = Join-Path $resolvedRepository '.codex_tmp'
New-Item -ItemType Directory -Path $temporaryParent -Force | Out-Null
$stagingRoot = Join-Path $temporaryParent (
    'seat-firmware-build-' + [guid]::NewGuid().ToString('N')
)
$stagingRootFull = [System.IO.Path]::GetFullPath($stagingRoot)
$temporaryParentFull = [System.IO.Path]::GetFullPath($temporaryParent)
if (-not $stagingRootFull.StartsWith(
    $temporaryParentFull + [System.IO.Path]::DirectorySeparatorChar,
    [System.StringComparison]::OrdinalIgnoreCase)) {
    throw "Firmware staging directory escaped repository temporary root: $stagingRootFull"
}

try {
    New-Item -ItemType Directory -Path $stagingRootFull | Out-Null
    $stagingProjectRoot = Join-Path $stagingRootFull 'Seat_Controller_demo'
    Copy-Item -LiteralPath $repositoryFirmware -Destination $stagingProjectRoot -Recurse
    New-Item -ItemType Junction -Path (Join-Path $stagingRootFull 'common') -Target $vendorCommon | Out-Null
    New-Item -ItemType Junction -Path (Join-Path $stagingRootFull 'tviibh8m') -Target $vendorDevice | Out-Null

    $stagedProject = Join-Path $stagingProjectRoot 'IAR\Seat_Controller_demo.ewp'
    Invoke-IarBuild -ProjectPath $stagedProject

    $stagedExe = Join-Path $stagingProjectRoot "IAR\$Configuration\Exe"
    $repositoryExe = Join-Path $repositoryFirmware "IAR\$Configuration\Exe"
    New-Item -ItemType Directory -Path $repositoryExe -Force | Out-Null
    foreach ($artifact in @('Seat_Controller_demo.hex', 'Seat_Controller_demo.out')) {
        $sourceArtifact = Join-Path $stagedExe $artifact
        if (-not (Test-Path -LiteralPath $sourceArtifact -PathType Leaf)) {
            throw "IAR build did not produce $sourceArtifact"
        }
        Copy-Item -LiteralPath $sourceArtifact -Destination (
            Join-Path $repositoryExe $artifact
        ) -Force
    }
    Write-ImageSummary -ImagePath (
        Join-Path $repositoryExe 'Seat_Controller_demo.hex'
    )
}
finally {
    if (Test-Path -LiteralPath $stagingRootFull) {
        foreach ($dependencyLink in @('common', 'tviibh8m')) {
            $linkPath = Join-Path $stagingRootFull $dependencyLink
            if (Test-Path -LiteralPath $linkPath) {
                $link = Get-Item -LiteralPath $linkPath -Force
                if (($link.Attributes -band [System.IO.FileAttributes]::ReparsePoint) -eq 0) {
                    throw "Refusing to remove non-junction dependency path: $linkPath"
                }
                [System.IO.Directory]::Delete($linkPath, $false)
            }
        }
        $remainingLinks = @(
            Get-ChildItem -LiteralPath $stagingRootFull -Recurse -Force -Attributes ReparsePoint -ErrorAction SilentlyContinue
        )
        if ($remainingLinks.Count -ne 0) {
            throw "Refusing recursive cleanup because a reparse point remains in $stagingRootFull"
        }
        [System.IO.Directory]::Delete($stagingRootFull, $true)
    }
}

Write-Host 'Build complete. This script never flashes or starts a physical actuator.'