. $PSScriptRoot\..\..\Load-PesterModules.ps1
$here = Split-Path -Parent $MyInvocation.MyCommand.Path
$sut = (Split-Path -Leaf $MyInvocation.MyCommand.Path) -replace '\.tests\.', '.'
$functionPath = Join-Path -Path $here -ChildPath $sut
Write-Host "Overriding SUT: $functionPath"
Import-Module $functionPath -Force
$moduleForMock = ""

#region Get-FileEncoding

$asciiTestString = "The quick brown fox jumps over the lazy dog"
$nonasciiTestString = [string]::Join('',('z', 'a', [char]0x0306, [char]0x01FD, [char]0x03B2, [char]0xD8FF, [char]0xDCFF))

$asciiEncodingExpectedResult = ([System.Text.Encoding]::ASCII).ToString()
$utf8EncodingExpectedResult = ([System.Text.Encoding]::UTF8).ToString()
$uniEncodingExpectedResult = ([System.Text.Encoding]::Unicode).ToString()
$utf7EncodingExpectedResult = ([System.Text.Encoding]::UTF7).ToString()

Describe "Get-FileEncoding" -Tags @("Integration") {
    Mock -ModuleName $moduleForMock Get-LogLeadName { "UUT: Get-FileEncoding" }
    Mock -ModuleName $moduleForMock Write-Host {}

    It "reads a known ASCII file as ASCII" {
        $testDrivePath = "TestDrive:\ascii.txt"
        Set-Content -Path $testDrivePath -Value $asciiTestString -Encoding ASCII
        $result = Get-FileEncoding $testDrivePath

        $result.Encoding | Should -Be $asciiEncodingExpectedResult
    }

    It "reads a known UTF8 file with ASCII text as UTF8" {
        $testDrivePath = "TestDrive:\UTF8.txt"
        Set-Content -Path $testDrivePath -Value $asciiTestString -Encoding UTF8
        $result = Get-FileEncoding $testDrivePath

        $result.Encoding | Should -Be $utf8EncodingExpectedResult
    }

    It "reads a known UTF8 file with non-ASCII text as UTF8" {
        $testDrivePath = "TestDrive:\UTF8.txt"
        Set-Content -Path $testDrivePath -Value $nonasciiTestString -Encoding UTF8
        $result = Get-FileEncoding $testDrivePath

        $result.Encoding | Should -Be $utf8EncodingExpectedResult
    }

    It "reads a known Unicode file with non-ASCII text as Unicode" {
        $testDrivePath = "TestDrive:\Unicode.txt"
        Set-Content -Path $testDrivePath -Value $nonasciiTestString -Encoding Unicode
        $result = Get-FileEncoding $testDrivePath

        $result.Encoding | Should -Be $uniEncodingExpectedResult
    }

    It "reads a known Unicode file with ASCII text as Unicode" {
        $testDrivePath = "TestDrive:\Unicode.txt"
        Set-Content -Path $testDrivePath -Value $asciiTestString -Encoding Unicode
        $result = Get-FileEncoding $testDrivePath

        $result.Encoding | Should -Be $uniEncodingExpectedResult
    }

    # Not running theascii scenario for UTF7
    # It's impossible to read a UTF7 file as UTF7 if it only contains ASCII.
    # UTF7 is a variant of base64 or urlencode for Unicode chars to ASCII files
    It "reads a known UTF7 file with non-ASCII text as UTF7" {
        $testDrivePath = "TestDrive:\UTF7.txt"
        Set-Content -Path $testDrivePath -Value $nonasciiTestString -Encoding UTF7
        $result = Get-FileEncoding $testDrivePath -TestForUTF7

        $result.Encoding | Should -Be $utf7EncodingExpectedResult
    }

    It "reads a known exe file as MZ/PE/NE" {
        $testDrivePath = "c:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe"

        # This file "should" exist if we are testing on Windows.
        # Seems like testing for powershell is an easy win :D ows trick. See what I did there?
        # This is just to prove that testing for PE/NE/MZ files does the thing because .NET .dll files are also PE/NE/MZ
        if (Test-Path $testDrivePath) {
            # this is brittle because if someone updates the result from the actual function, this will break
            $brittleTestStringResult = 'Windows MZ/PE/NE or SYS (driver) file'
            $result = Get-FileEncoding $testDrivePath

            $result.Description | Should -Be $brittleTestStringResult
        }
    }
}

#endregion Get-FileEncoding