# Shared helpers for USMT-Server.ps1, USMT-Worker.ps1 and Get-Software.ps1.
# Dot-source this file; it must stay compatible with Windows PowerShell 5.1 and PowerShell 7.

function Import-DashConfig {
    param([string]$Path, [switch]$Demo)

    if (-not $Path) { $Path = Join-Path (Split-Path $PSScriptRoot -Parent) "Config\usmt-dash.psd1" }
    $Path = $Path -replace '[\\/]', [System.IO.Path]::DirectorySeparatorChar
    if (-not (Test-Path $Path)) { throw "Config file not found: $Path" }

    $cfg = Import-PowerShellDataFile -Path $Path
    if ($Demo -or $env:USMT_MODE -eq 'Demo') { $cfg.Mode = 'Demo' }
    $cfg.IsDemo = ($cfg.Mode -eq 'Demo')
    return $cfg
}

function Join-DashPath {
    # Join-Path that tolerates the backslash-separated relative paths used in config on Linux
    param([string]$Base, [string]$Child)
    return Join-Path $Base ($Child -replace '[\\/]', [System.IO.Path]::DirectorySeparatorChar)
}

# -----------------------------------------------------------------------------------------
#  Console log mirror
#
#  Write-Host is proxied so every line printed to the console is also appended to a JSON
#  lines file: {"i":<id>,"t":"<time>","s":[["text","Color"],...]}. The server's /get-logs
#  route tails that file for the dashboard terminal panel. Call sites are unchanged.
# -----------------------------------------------------------------------------------------
$script:ConsoleLog = $null

function Initialize-ConsoleLog {
    param([string]$Path, [int]$MaxLines = 3000, [string]$CommandLine)

    $dir = Split-Path $Path -Parent
    if (-not (Test-Path $dir)) { New-Item -ItemType Directory -Path $dir -Force | Out-Null }

    $script:ConsoleLog = @{
        Path     = $Path
        MaxLines = $MaxLines
        NextId   = [long]([DateTimeOffset]::UtcNow.ToUnixTimeMilliseconds()) * 1000
        Pending  = [System.Collections.Generic.List[object]]::new()
        Written  = 0
    }
    if ($CommandLine) { Add-ConsoleLogLine -Segments @(, @($CommandLine, 'Prompt')) }
}

function ConvertTo-JsonString([string]$s) {
    $sb = [System.Text.StringBuilder]::new('"')
    foreach ($ch in $s.ToCharArray()) {
        switch ($ch) {
            '"'  { [void]$sb.Append('\"') }
            '\'  { [void]$sb.Append('\\') }
            "`r" { }
            "`t" { [void]$sb.Append('\t') }
            default {
                if ([int]$ch -lt 32) { [void]$sb.AppendFormat('\u{0:x4}', [int]$ch) } else { [void]$sb.Append($ch) }
            }
        }
    }
    [void]$sb.Append('"')
    return $sb.ToString()
}

function Add-ConsoleLogLine {
    param([object[]]$Segments)
    $log = $script:ConsoleLog
    if (-not $log) { return }

    $log.NextId++
    $segJson = ($Segments | ForEach-Object { "[" + (ConvertTo-JsonString $_[0]) + "," + (ConvertTo-JsonString $_[1]) + "]" }) -join ','
    $line = '{"i":' + $log.NextId + ',"t":"' + (Get-Date).ToString('HH:mm:ss') + '","s":[' + $segJson + ']}'

    for ($try = 0; $try -lt 5; $try++) {
        try { [System.IO.File]::AppendAllText($log.Path, $line + "`n"); break }
        catch { Start-Sleep -Milliseconds 20 }
    }

    $log.Written++
    if ($log.Written % 250 -eq 0) { Limit-ConsoleLog }
}

function Limit-ConsoleLog {
    $log = $script:ConsoleLog
    try {
        $lines = [System.IO.File]::ReadAllLines($log.Path)
        if ($lines.Count -gt $log.MaxLines) {
            $keep = $lines[($lines.Count - $log.MaxLines)..($lines.Count - 1)]
            $tmp = "$($log.Path).tmp"
            [System.IO.File]::WriteAllLines($tmp, $keep)
            Move-Item -Path $tmp -Destination $log.Path -Force
        }
    } catch {}
}

function Write-Host {
    param(
        [Parameter(Position = 0)][object]$Object = '',
        [switch]$NoNewline,
        [object]$Separator = ' ',
        [System.ConsoleColor]$ForegroundColor,
        [System.ConsoleColor]$BackgroundColor
    )
    Microsoft.PowerShell.Utility\Write-Host @PSBoundParameters

    $log = $script:ConsoleLog
    if (-not $log) { return }

    $color = if ($PSBoundParameters.ContainsKey('ForegroundColor')) { "$ForegroundColor" } else { 'Default' }
    $parts = "$Object" -split "`n"
    for ($p = 0; $p -lt $parts.Count; $p++) {
        if ($parts[$p] -ne '') { $log.Pending.Add(@($parts[$p], $color)) }
        $isLast = ($p -eq $parts.Count - 1)
        if (-not $isLast -or -not $NoNewline) {
            Add-ConsoleLogLine -Segments $log.Pending.ToArray()
            $log.Pending.Clear()
        }
    }
}

# Reads a file without locking it against the other process (worker writes while server reads)
function Read-SharedText {
    param([string]$Path)
    $fs = New-Object System.IO.FileStream($Path, [System.IO.FileMode]::Open, [System.IO.FileAccess]::Read, [System.IO.FileShare]::ReadWrite)
    try {
        $sr = New-Object System.IO.StreamReader($fs)
        return $sr.ReadToEnd()
    } finally { $fs.Close() }
}