#Requires -Version 5.1
<#
.SYNOPSIS
    Installs bash-for-windows and registers it as a Windows Terminal profile.
.DESCRIPTION
    Copies bash.exe to a permanent location, adds it to the user PATH,
    and adds a "Bash for Windows" entry to Windows Terminal so it appears
    in the new-tab dropdown.
.EXAMPLE
    .\install.ps1
    .\install.ps1 -InstallDir "$env:APPDATA\BashForWindows"
    .\install.ps1 -NoPath -NoTerminal
    .\install.ps1 -Uninstall
#>

param(
    [string]$InstallDir  = "$env:LOCALAPPDATA\Programs\BashForWindows",
    [switch]$NoPath,
    [switch]$NoTerminal,
    [switch]$Uninstall
)

$ErrorActionPreference = "Stop"

$ExeName     = "bash.exe"
$ProfileGuid = "{7a86baf2-f5b9-4b78-b3f8-5e1e4f3d9b2a}"
$ProfileName = "Bash for Windows"

# ── Pretty output helpers ─────────────────────────────────────────────────────

function Write-Header {
    Write-Host ""
    Write-Host "  bash-for-windows" -ForegroundColor White -NoNewline
    Write-Host " installer" -ForegroundColor DarkGray
    Write-Host "  ─────────────────────────────────────────" -ForegroundColor DarkGray
}

function Write-Step  { param([string]$s) Write-Host "`n  ▸ $s" -ForegroundColor Cyan }
function Write-Ok    { param([string]$s) Write-Host "    ✓  $s" -ForegroundColor Green }
function Write-Warn  { param([string]$s) Write-Host "    ⚠  $s" -ForegroundColor Yellow }
function Write-Fatal { param([string]$s) Write-Host "    ✗  $s" -ForegroundColor Red; exit 1 }

# ── Locate source bash.exe (must live next to this script) ────────────────────

$ScriptDir = Split-Path -Parent $MyInvocation.MyCommand.Definition
$SourceExe = Join-Path $ScriptDir $ExeName

if (-not (Test-Path $SourceExe)) {
    Write-Header
    Write-Fatal "'$ExeName' not found next to this script.  Expected: $SourceExe"
}

# ── Windows Terminal settings.json locations ──────────────────────────────────

function Get-WTSettingsPath {
    @(
        "$env:LOCALAPPDATA\Packages\Microsoft.WindowsTerminal_8wekyb3d8bbwe\LocalState\settings.json",
        "$env:LOCALAPPDATA\Packages\Microsoft.WindowsTerminalPreview_8wekyb3d8bbwe\LocalState\settings.json",
        "$env:LOCALAPPDATA\Microsoft\Windows Terminal\settings.json"
    ) | Where-Object { Test-Path $_ } | Select-Object -First 1
}

# ── PATH helpers ──────────────────────────────────────────────────────────────

function Add-ToUserPath {
    param([string]$Dir)
    $current = [Environment]::GetEnvironmentVariable("PATH", "User") -split ";" |
               Where-Object { $_ -ne "" }
    if ($Dir -in $current) {
        Write-Warn "Already in user PATH: $Dir"
        return
    }
    [Environment]::SetEnvironmentVariable("PATH", (($current + $Dir) -join ";"), "User")
    Write-Ok "Added to user PATH: $Dir"
    Write-Warn "Re-open your terminal for the PATH change to take effect."
}

function Remove-FromUserPath {
    param([string]$Dir)
    $current = [Environment]::GetEnvironmentVariable("PATH", "User") -split ";" |
               Where-Object { $_ -ne "" -and $_ -ne $Dir }
    [Environment]::SetEnvironmentVariable("PATH", ($current -join ";"), "User")
    Write-Ok "Removed from user PATH: $Dir"
}

# ── Windows Terminal profile helpers ──────────────────────────────────────────

function Register-WTProfile {
    param([string]$ExePath)

    $settingsPath = Get-WTSettingsPath
    if (-not $settingsPath) {
        Write-Warn "Windows Terminal not found — skipping profile registration."
        Write-Warn "Install Windows Terminal from the Microsoft Store and re-run the installer."
        return
    }

    try {
        $raw  = Get-Content $settingsPath -Raw -Encoding UTF8
        $json = $raw | ConvertFrom-Json
    } catch {
        Write-Warn "Could not parse settings.json: $_"
        return
    }

    # Build the profile object
    $newProfile = [PSCustomObject]@{
        guid             = $ProfileGuid
        name             = $ProfileName
        commandline      = $ExePath
        startingDirectory = "%USERPROFILE%"
        hidden           = $false
    }

    # Ensure profiles.list exists
    if (-not $json.PSObject.Properties["profiles"]) {
        Add-Member -InputObject $json -MemberType NoteProperty `
                   -Name "profiles" -Value ([PSCustomObject]@{ list = @() })
    }
    if (-not $json.profiles.PSObject.Properties["list"]) {
        Add-Member -InputObject $json.profiles -MemberType NoteProperty `
                   -Name "list" -Value @() -Force
    }

    $list = @($json.profiles.list)

    # Find existing entry by GUID
    $existingIdx = -1
    for ($i = 0; $i -lt $list.Count; $i++) {
        if ($list[$i].guid -eq $ProfileGuid) { $existingIdx = $i; break }
    }

    if ($existingIdx -ge 0) {
        $list[$existingIdx] = $newProfile
        Write-Ok "Updated existing '$ProfileName' profile."
    } else {
        # Prepend so it appears near the top of the dropdown
        $list = @($newProfile) + $list
        Write-Ok "Added '$ProfileName' profile."
    }

    $json.profiles.list = $list

    # Write back — high depth so nested keybindings etc. aren't truncated
    $updated = $json | ConvertTo-Json -Depth 50
    [System.IO.File]::WriteAllText($settingsPath, $updated, [System.Text.UTF8Encoding]::new($false))
    Write-Ok "Saved settings: $settingsPath"
    Write-Ok "Open Windows Terminal, click '+', and select '$ProfileName'."
}

function Remove-WTProfile {
    $settingsPath = Get-WTSettingsPath
    if (-not $settingsPath) { return }

    try {
        $json = Get-Content $settingsPath -Raw -Encoding UTF8 | ConvertFrom-Json
    } catch { return }

    if (-not $json.profiles -or -not $json.profiles.list) { return }

    $list = @($json.profiles.list) | Where-Object { $_.guid -ne $ProfileGuid }
    $json.profiles.list = $list
    $updated = $json | ConvertTo-Json -Depth 50
    [System.IO.File]::WriteAllText($settingsPath, $updated, [System.Text.UTF8Encoding]::new($false))
    Write-Ok "Removed '$ProfileName' from Windows Terminal."
}

# ─────────────────────────────────────────────────────────────────────────────
# UNINSTALL
# ─────────────────────────────────────────────────────────────────────────────

if ($Uninstall) {
    Write-Header
    Write-Step "Removing files"
    if (Test-Path $InstallDir) {
        Remove-Item $InstallDir -Recurse -Force
        Write-Ok "Deleted: $InstallDir"
    } else {
        Write-Warn "Not found (already removed?): $InstallDir"
    }

    Write-Step "Removing from PATH"
    Remove-FromUserPath $InstallDir

    Write-Step "Removing Windows Terminal profile"
    Remove-WTProfile

    Write-Host "`n  Uninstall complete." -ForegroundColor Green
    Write-Host ""
    exit 0
}

# ─────────────────────────────────────────────────────────────────────────────
# INSTALL
# ─────────────────────────────────────────────────────────────────────────────

Write-Header

Write-Step "Installing binary"
New-Item -ItemType Directory -Path $InstallDir -Force | Out-Null
$DestExe = Join-Path $InstallDir $ExeName
Copy-Item -Path $SourceExe -Destination $DestExe -Force
Write-Ok "Copied to: $DestExe"

if (-not $NoPath) {
    Write-Step "Updating user PATH"
    Add-ToUserPath $InstallDir
}

if (-not $NoTerminal) {
    Write-Step "Registering Windows Terminal profile"
    Register-WTProfile $DestExe
}

Write-Host "`n  Install complete." -ForegroundColor Green
Write-Host ""