param(
    [Parameter(Mandatory = $true)]
    [string]$Name,
    [Parameter(Mandatory = $true)]
    [string]$TargetDir,
    [string]$TopModule = "top"
)

$ErrorActionPreference = "Stop"
$templateRoot = Join-Path (Split-Path $PSScriptRoot -Parent) "templates"

if (Test-Path $TargetDir) {
    throw "Target already exists: $TargetDir"
}

New-Item -ItemType Directory -Force -Path (Join-Path $TargetDir "src") | Out-Null

# gprj
$gprj = @"
<?xml version="1" encoding="UTF-8"?>
<!DOCTYPE gowin-fpga-project>
<Project>
    <Template>FPGA</Template>
    <Version>5</Version>
    <Device name="GW5A-25A" pn="GW5A-LV25UG324C2/I1">gw5a25a-008</Device>
    <FileList>
        <File path="src/$TopModule.v" type="file.verilog" enable="1"/>
        <File path="src/$TopModule.cst" type="file.cst" enable="1"/>
        <File path="src/$TopModule.sdc" type="file.sdc" enable="1"/>
    </FileList>
</Project>
"@
[System.IO.File]::WriteAllText((Join-Path $TargetDir "$Name.gprj"), $gprj, (New-Object System.Text.UTF8Encoding $false))

# build.tcl (ASCII, no BOM)
$tcl = @"
open_project $Name.gprj
set_option -output_base_name $Name
set_option -synthesis_tool gowinsynthesis
set_option -top_module $TopModule
set_option -use_sspi_as_gpio 1
set_option -use_mspi_as_gpio 1
set_option -use_ready_as_gpio 1
set_option -use_done_as_gpio 1
set_option -use_cpu_as_gpio 1
run all
exit
"@
[System.IO.File]::WriteAllText((Join-Path $TargetDir "build.tcl"), $tcl, (New-Object System.Text.UTF8Encoding $false))

Copy-Item (Join-Path $templateRoot "src\top.v") (Join-Path $TargetDir "src\$TopModule.v")
Copy-Item (Join-Path $templateRoot "src\top.cst") (Join-Path $TargetDir "src\$TopModule.cst")
Copy-Item (Join-Path $templateRoot "src\top.sdc") (Join-Path $TargetDir "src\$TopModule.sdc")

# fix module name inside copied files
$v = Get-Content (Join-Path $TargetDir "src\$TopModule.v") -Raw
$v = $v -replace "module top", "module $TopModule"
[System.IO.File]::WriteAllText((Join-Path $TargetDir "src\$TopModule.v"), $v, (New-Object System.Text.UTF8Encoding $false))

Write-Host "Created project: $TargetDir"
Write-Host "Next: gwin-skill\scripts\build_and_download.ps1 -ProjectDir $TargetDir"