# E01-S05: link the memory-map skeleton against cfg/compiler.cfg.
#   build-map-skeleton.ps1                 normal build, prints segment usage
#   build-map-skeleton.ps1 -Overflow ZP    build that must fail in ld65
[CmdletBinding()]
param(
    [ValidateSet("", "ZP", "COMMON", "MAIN", "SWSTACK", "TABLES")]
    [string]$Overflow = ""
)

$ErrorActionPreference = "Stop"
$project = Split-Path $PSScriptRoot -Parent
$build = Join-Path $project "build"
$config = Join-Path $project "cfg\compiler.cfg"
$sources = @(
    (Join-Path $project "src\compiler\mmu.s"),
    (Join-Path $project "tests\platform\map-skeleton.s")
)
$suffix = if ($Overflow) { "-overflow-" + $Overflow.ToLowerInvariant() } else { "" }
$stem = Join-Path $build ("map-skeleton" + $suffix)
$program = "$stem.prg"
$map = "$stem.map"
$labels = "$stem.lbl"

$ca65 = (Get-Command ca65 -ErrorAction Stop).Source
$ld65 = (Get-Command ld65 -ErrorAction Stop).Source
New-Item -ItemType Directory -Force -Path $build | Out-Null
foreach ($path in @($program, $map, $labels)) {
    if (Test-Path -LiteralPath $path) { Remove-Item -LiteralPath $path -Force }
}

$objects = @()
foreach ($source in $sources) {
    $object = Join-Path $build (([IO.Path]::GetFileNameWithoutExtension($source)) + $suffix + ".o")
    $defines = @()
    if ($Overflow) { $defines = @("-D", "OVERFLOW_$Overflow=1") }
    & $ca65 --cpu 6502 @defines -o $object $source
    if ($LASTEXITCODE -ne 0) { throw "ca65 failed on $source" }
    $objects += $object
}

$linkOutput = & $ld65 -C $config -o $program -m $map -Ln $labels @objects 2>&1
$linkExit = $LASTEXITCODE
if ($Overflow) {
    $text = ($linkOutput | Out-String)
    if ($linkExit -eq 0) { throw "OVERFLOW_$Overflow linked; capacity check failed to fire" }
    if ($text -notmatch "(?i)overflows memory area") {
        throw "OVERFLOW_$Overflow failed for an unexpected reason: $text"
    }
    $area = [regex]::Match($text, "(?i)overflows memory area\W+(\w+)").Groups[1].Value
    Write-Host ("overflow {0}: ld65 rejected it (memory area {1})" -f $Overflow, $area)
    return
}
if ($linkExit -ne 0) { throw ("ld65 failed:`n" + ($linkOutput | Out-String)) }

# Segment usage from the map file: name, start, end, size.
$segments = @{}
$mapText = Get-Content -Raw -LiteralPath $map
$block = [regex]::Match($mapText, "(?s)Segment list:.*?-{5,}\r?\n(.*?)\r?\n\r?\n").Groups[1].Value
foreach ($line in ($block -split "\r?\n")) {
    $m = [regex]::Match($line, "^(\w+)\s+([0-9A-F]{6})\s+([0-9A-F]{6})\s+([0-9A-F]{6})")
    if ($m.Success) {
        $segments[$m.Groups[1].Value] = @{
            Start = [Convert]::ToInt32($m.Groups[2].Value, 16)
            End = [Convert]::ToInt32($m.Groups[3].Value, 16)
            Size = [Convert]::ToInt32($m.Groups[4].Value, 16)
        }
    }
}

# Contract checks that ld65 cannot express: fixed placements.
function Require-Segment([string]$name, [int]$lo, [int]$hi) {
    if (-not $segments.ContainsKey($name)) { throw "segment $name missing from map" }
    $seg = $segments[$name]
    if ($seg.Size -gt 0 -and ($seg.Start -lt $lo -or $seg.End -gt $hi)) {
        throw ("segment {0} `${1:X4}-`${2:X4} outside `${3:X4}-`${4:X4}" -f
            $name, $seg.Start, $seg.End, $lo, $hi)
    }
}
Require-Segment "ZEROPAGE" 0x0002 0x00FF
Require-Segment "COMMON" 0x1300 0x18FF
Require-Segment "MAILBOX" 0x1BF0 0x1BFF
Require-Segment "STARTUP" 0x1C0D 0xB7FF
Require-Segment "CODE" 0x1C0D 0xB7FF
if ($segments["STARTUP"].Start -ne 0x1C0D) { throw "STARTUP does not begin at `$1C0D" }
$labelText = Get-Content -Raw -LiteralPath $labels
if ($labelText -notmatch "(?im)^al\s+001C0D\s+\.skel_entry\s*$") {
    throw "skel_entry is not at `$1C0D (the SYS 7181 target)"
}
Require-Segment "SWSTACK" 0xB800 0xBFFF
Require-Segment "TABLES" 0x6B00 0xBFFF
if ($segments["MAILBOX"].Start -ne 0x1BF0) { throw "mailbox is not at `$1BF0" }

$bytes = [IO.File]::ReadAllBytes($program)
if ($bytes[0] -ne 0x01 -or $bytes[1] -ne 0x1C) { throw "load address is not `$1C01" }

Write-Host ("built {0} ({1} bytes)" -f $program, $bytes.Length)
$limits = [ordered]@{
    ZEROPAGE = 0x00FE; COMMON = 0x0600; SWSTACK = 0x0800; TABLES = 0x5500
}
foreach ($name in ($segments.Keys | Sort-Object { $segments[$_].Start })) {
    $seg = $segments[$name]
    $limit = if ($limits.Contains($name)) { " of {0}" -f $limits[$name] } else { "" }
    Write-Host ("  {0,-9} `${1:X4}-`${2:X4} {3,6} bytes{4}" -f
        $name, $seg.Start, $seg.End, $seg.Size, $limit)
}