# Shared helpers for the ebook-skill command line (Windows PowerShell 5.1+ / pwsh 7+).

$ErrorActionPreference = 'Stop'

function Get-ProjectRoot {
    param([string]$Start = $PSScriptRoot)
    $dir = (Resolve-Path $Start).Path
    while ($dir) {
        if (Test-Path (Join-Path $dir 'vendor\so-novel\pom.xml')) { return $dir }
        $parent = Split-Path $dir -Parent
        if ($parent -eq $dir -or -not $parent) { break }
        $dir = $parent
    }
    throw "Cannot locate project root (vendor/so-novel/pom.xml not found above $Start). Run: git submodule update --init"
}

function Get-ToolPaths {
    param([string]$Root = (Get-ProjectRoot))
    [pscustomobject]@{
        Root    = $Root
        Vendor  = Join-Path $Root 'vendor\so-novel'
        Tools   = Join-Path $Root 'tools'
        Runtime = Join-Path $Root 'tools\runtime'
        Build   = Join-Path $Root 'tools\build'
        Classes = Join-Path $Root 'tools\build\classes'
        AppJar  = Join-Path $Root 'tools\runtime\app.jar'
        ToolJar = Join-Path $Root 'tools\runtime\sonovel-tool.jar'
        Config  = Join-Path $Root 'tools\runtime\config.ini'
        Rules   = Join-Path $Root 'tools\runtime\rules'
        Books   = Join-Path $Root 'books'
    }
}

function Test-Jdk21 {
    param([string]$JdkHome)
    if (-not $JdkHome) { return $false }
    $java = Join-Path $JdkHome 'bin\java.exe'
    if (-not (Test-Path $java)) { return $false }
    try {
        $out = (& $java -version 2>&1 | Out-String)
    } catch {
        return $false
    }
    if ($out -match 'version "(?:1\.)?(\d+)') {
        return ([int]$Matches[1] -ge 21)
    }
    return $false
}

function Find-Jdk21 {
    param([switch]$AllowDownload)

    $candidates = New-Object System.Collections.Generic.List[string]
    if ($env:EBOOK_NOVEL_JAVA_HOME) { $candidates.Add($env:EBOOK_NOVEL_JAVA_HOME) }
    if ($env:JAVA_HOME) { $candidates.Add($env:JAVA_HOME) }

    $patterns = @(
        (Join-Path $PSScriptRoot '.jdk\*\*'),
        (Join-Path $PSScriptRoot '.jdk'),
        'C:\Program Files\Java\jdk-21*',
        'C:\Program Files\Eclipse Adoptium\jdk-21*',
        'C:\Program Files\JetBrains\*\jbr',
        (Join-Path $env:LOCALAPPDATA 'mise\installs\java\21*'),
        (Join-Path $env:LOCALAPPDATA 'mise\installs\java\2*')
    )
    foreach ($pattern in $patterns) {
        foreach ($dir in (Get-ChildItem -Path $pattern -Directory -ErrorAction SilentlyContinue)) {
            $candidates.Add($dir.FullName)
        }
    }

    foreach ($candidate in $candidates) {
        if (Test-Jdk21 -JdkHome $candidate) { return (Resolve-Path $candidate).Path }
    }

    if ($AllowDownload) { return (Install-Jdk21) }
    return $null
}

# Downloads a portable Temurin JDK 21 (used only when no local JDK 21 exists).
function Install-Jdk21 {
    $dest = Join-Path $PSScriptRoot '.jdk'
    New-Item -ItemType Directory -Force $dest | Out-Null

    Write-Host '[setup] no JDK 21 found, downloading Temurin 21 from the Tsinghua mirror ...' -ForegroundColor Yellow
    $mirror = 'https://mirrors.tuna.tsinghua.edu.cn/Adoptium/21/jdk/x64/windows/'
    $listing = (Invoke-WebRequest -Uri $mirror -UseBasicParsing -TimeoutSec 60).Content
    $names = [regex]::Matches($listing, 'OpenJDK21U-jdk_x64_windows_hotspot_[0-9._]+\.zip') |
        ForEach-Object { $_.Value } | Sort-Object -Unique
    if (-not $names) { throw "Could not find a JDK 21 archive at $mirror" }
    $zipName = $names[$names.Count - 1]

    $zip = Join-Path $env:TEMP $zipName
    if (-not (Test-Path $zip)) {
        Invoke-WebRequest -Uri ($mirror + $zipName) -OutFile $zip -UseBasicParsing -TimeoutSec 1800
    }
    Expand-Archive -Path $zip -DestinationPath $dest -Force

    $java = Get-ChildItem -Path (Join-Path $dest '*\bin\java.exe') -ErrorAction SilentlyContinue | Select-Object -First 1
    if (-not $java) { throw "JDK extraction failed under $dest" }
    $JdkHome = Split-Path (Split-Path $java.FullName -Parent) -Parent
    Write-Host "[setup] JDK 21 installed at $JdkHome" -ForegroundColor Green
    return $JdkHome
}

function Get-JavaCommand {
    param([string]$Root = (Get-ProjectRoot))
    $jdkHome = Find-Jdk21
    if (-not $jdkHome) {
        throw 'JDK 21 is required. Run tools\build.ps1 (it can download one), or set EBOOK_NOVEL_JAVA_HOME.'
    }
    return (Join-Path $jdkHome 'bin\java.exe')
}

function Find-JarTool {
    # JBR ships without jar.exe, so fall back to any other JDK on the machine.
    foreach ($pattern in @('C:\Program Files\Java\*\bin\jar.exe',
                           (Join-Path $env:LOCALAPPDATA 'mise\installs\java\*\bin\jar.exe'),
                           'C:\Program Files\Eclipse Adoptium\*\bin\jar.exe')) {
        $exe = Get-ChildItem -Path $pattern -ErrorAction SilentlyContinue | Select-Object -First 1
        if ($exe) { return $exe.FullName }
    }
    $cmd = Get-Command jar.exe -ErrorAction SilentlyContinue
    if ($cmd) { return $cmd.Source }
    return $null
}