<#
.SYNOPSIS
    Install a built CMBot release into the local launcher layout.

.DESCRIPTION
    Creates or updates this structure:

      %LOCALAPPDATA%\CMBot\
        update.ps1
        app\
        app.old\
        data\
          config\
          logs\
          output\
        staging\

    The script copies a built release directory (release\CMBot-x.y.z by default)
    into app\, copies scripts\update.ps1 to the install root, and migrates
    config files into data\config without overwriting existing user config.

.PARAMETER ReleaseDir
    Built release directory to install. Defaults to release\CMBot-APP_VERSION.

.PARAMETER InstallRoot
    Local install root. Defaults to %LOCALAPPDATA%\CMBot.

.PARAMETER LegacyDataDir
    Optional old flat install/data root. When provided, config files are copied
    from LegacyDataDir\config before falling back to app.old\config or release
    defaults.

.PARAMETER Force
    Allows replacing an existing app.old directory.
#>
[CmdletBinding()]
param(
    [string]$ReleaseDir = "",
    [string]$InstallRoot = (Join-Path $env:LOCALAPPDATA "CMBot"),
    [string]$LegacyDataDir = "",
    [switch]$Force
)

$ErrorActionPreference = "Stop"

$ScriptDir = Split-Path -Parent $MyInvocation.MyCommand.Path
$RootDir = Split-Path -Parent $ScriptDir
$VersionFile = Join-Path $RootDir "src\version.py"
$ReleaseRoot = Join-Path $RootDir "release"
$LauncherScript = Join-Path $ScriptDir "update.ps1"
$AppExeName = "CMBot"
$AppExe = "$AppExeName.exe"

function Read-VersionValue {
    param(
        [string]$Path,
        [string]$Name
    )

    $pattern = "^\s*$Name\s*=\s*`"([^`"]+)`""
    foreach ($line in Get-Content -LiteralPath $Path -Encoding UTF8) {
        if ($line -match $pattern) {
            return $Matches[1]
        }
    }
    throw "Cannot find $Name in $Path"
}

function Resolve-ExistingPath {
    param(
        [string]$Path,
        [string]$Name
    )
    if (-not (Test-Path -LiteralPath $Path)) {
        throw "$Name not found: $Path"
    }
    return (Resolve-Path -LiteralPath $Path).Path
}

function Assert-Release {
    param([string]$Path)
    $exe = Join-Path $Path $AppExe
    $version = Join-Path $Path "version.txt"
    if (-not (Test-Path -LiteralPath $exe)) {
        throw "Release missing executable: $exe"
    }
    if (-not (Test-Path -LiteralPath $version)) {
        throw "Release missing version.txt: $version"
    }
}

function Copy-ConfigIfMissing {
    param(
        [string]$SourceConfigDir,
        [string]$TargetConfigDir,
        [string]$FileName
    )
    if (-not $SourceConfigDir) {
        return
    }
    $source = Join-Path $SourceConfigDir $FileName
    $target = Join-Path $TargetConfigDir $FileName
    if ((Test-Path -LiteralPath $source) -and -not (Test-Path -LiteralPath $target)) {
        Copy-Item -LiteralPath $source -Destination $target
        Write-Host "Migrated config: $FileName"
    }
}

if (-not $ReleaseDir) {
    $appVersion = Read-VersionValue -Path $VersionFile -Name "APP_VERSION"
    $ReleaseDir = Join-Path $ReleaseRoot "$AppExeName-$appVersion"
}

$ReleaseDir = Resolve-ExistingPath -Path $ReleaseDir -Name "Release directory"
$LauncherScript = Resolve-ExistingPath -Path $LauncherScript -Name "Launcher script"
Assert-Release -Path $ReleaseDir

$InstallRoot = [System.IO.Path]::GetFullPath($InstallRoot)
$AppDir = Join-Path $InstallRoot "app"
$OldAppDir = Join-Path $InstallRoot "app.old"
$DataDir = Join-Path $InstallRoot "data"
$ConfigDir = Join-Path $DataDir "config"
$LogsDir = Join-Path $DataDir "logs"
$OutputDir = Join-Path $DataDir "output"
$StagingDir = Join-Path $InstallRoot "staging"

New-Item -ItemType Directory -Force -Path $InstallRoot | Out-Null
New-Item -ItemType Directory -Force -Path $ConfigDir | Out-Null
New-Item -ItemType Directory -Force -Path $LogsDir | Out-Null
New-Item -ItemType Directory -Force -Path $OutputDir | Out-Null
New-Item -ItemType Directory -Force -Path $StagingDir | Out-Null

if (Test-Path -LiteralPath $AppDir) {
    if (Test-Path -LiteralPath $OldAppDir) {
        if (-not $Force) {
            throw "app.old already exists: $OldAppDir. Re-run with -Force to replace it."
        }
        Remove-Item -LiteralPath $OldAppDir -Recurse -Force
    }
    Move-Item -LiteralPath $AppDir -Destination $OldAppDir
}

Copy-Item -LiteralPath $ReleaseDir -Destination $AppDir -Recurse
Copy-Item -LiteralPath $LauncherScript -Destination (Join-Path $InstallRoot "update.ps1") -Force

$configSources = @()
if ($LegacyDataDir) {
    $configSources += Join-Path ([System.IO.Path]::GetFullPath($LegacyDataDir)) "config"
}
if (Test-Path -LiteralPath $OldAppDir) {
    $configSources += Join-Path $OldAppDir "config"
}
$configSources += Join-Path $AppDir "config"

foreach ($sourceConfig in $configSources) {
    Copy-ConfigIfMissing -SourceConfigDir $sourceConfig -TargetConfigDir $ConfigDir -FileName "app_config.json"
    Copy-ConfigIfMissing -SourceConfigDir $sourceConfig -TargetConfigDir $ConfigDir -FileName "templates.json"
}

Write-Host "Installed CMBot launcher layout:"
Write-Host "  Root: $InstallRoot"
Write-Host "  App:  $AppDir"
Write-Host "  Data: $DataDir"
Write-Host ""
Write-Host "Start with:"
Write-Host "  powershell -ExecutionPolicy Bypass -File `"$InstallRoot\update.ps1`""