functions/Match-Vars.ps1

<#
    .PARAMETER simpleMode
    for better performance. do not perform variable substitution based on self and root
    should still work for simpler scenarios

#>


function _clone($obj) {
        Measure-function  "$($MyInvocation.MyCommand.Name)" {

    if ($obj -is [System.Collections.Specialized.OrderedDictionary]) {
        $copy = [ordered]@{}
        foreach($e in $obj.GetEnumerator()) {
            $copy.Add($e.Key, $e.Value)
        }

        return $copy
    }
    if ($obj.gettype().name -eq "Hashtable" -and $obj -isnot [Hashtable]) {
        $copy = @{}
        foreach($e in $obj.GetEnumerator()) {
            $copy.Add($e.Key, $e.Value)
        }

        return $copy
    }
    else {
        return $obj.Clone()
    }
        }
}

function get-entry(
    [Parameter(mandatory=$true,Position=1)] $key,
    [Parameter(mandatory=$true,ValueFromPipeline=$true,Position=2)] $map,
    $excludeProperties = @("project"),
    [switch][bool] $simpleMode = $false) {
            Measure-function  "$($MyInvocation.MyCommand.Name)" {

    $root = $map
    $parent = $null
    $entry = $null
    $splits=$key.split(".")
    for($i = 0; $i -lt $splits.length; $i++) {
        $split = $splits[$i]
        $parent = $entry
        if ($i -eq $splits.length-1) {
            $key = $split
            if ($null -ne $map[$key]) { 
                $entry = $map[$key] 
                $vars = @()
            }
            elseif ($key -eq "/" -or $key -eq "\") {
                $entry = $map
                $vars = @()
            } 
            else {     
                foreach($kvp in $map.GetEnumerator()) {
                    $pattern = $kvp.key
                    $vars = _MatchVarPattern $key "$pattern"
                    if ($null -ne $vars) {
                        $entry = $kvp.value   
                        break
                    }
                }
            }

            if ($null -ne $entry) {
                #TODO: should we use a deep clone
                $entry2 = _clone $entry
                if ($entry2 -is [Hashtable]) {
                    $entry2._vars = $vars
                }             
                $warnaction = "SilentlyContinue"
                if ($simpleMode) {
                    $warnaction = "Continue" 
                }
                $entry2 = replace-properties $entry2 -vars $vars -exclude $excludeProperties -WarningAction $warnaction
                if (!$simpleMode) {
                    # replace properties based on self values
                    $entry2 = replace-properties $entry2 -vars $map -exclude $excludeProperties -WarningAction "SilentlyContinue"
                    # replace properties based on root values
                    $entry2 = replace-properties $entry2 -vars $root -exclude $excludeProperties  
                }
                return $entry2
            }

            return $entry
        }
        else {
            $entry = $map.$split
        }
        if ($null -eq $entry) {
            break
        }
        if ($null -ne $entry -and $null -ne $entry.group) {
            $isGroup = $true
            break
        }
        $map = $entry
    }    

            }
}

function Convert-PropertiesFromVars { 
    [CmdletBinding()]
    param($obj, $vars = @{}, [switch][bool]$strict, $exclude = @()) 
    Measure-function  "$($MyInvocation.MyCommand.Name)" {

    $exclude = @($exclude)
    if ($null -eq $vars) {
        throw "vars == NULL"
    }
    if ($obj -is [string]) {
        $replaced = replace-vars -text $obj -vars $vars
        return $replaced
    }
    elseif ($obj -is [System.Collections.IDictionary]) {
        $keys = _clone $obj.keys
        $keys = $keys | Sort-Object        
        foreach($key in $keys) {
            if ($key -notin $exclude) {
                if ($obj[$key] -in $exclude) {
                    continue
                }
                $self = $obj
                try {
                    $obj[$key] = replace-properties $obj[$key] $vars -exclude ($exclude + @($obj))
                }
                finally {
                    $self = $null
                }
                
            }
        }
        return $obj
    }
    elseif ($obj -is [Array]) {
        $obj = _clone $obj
        for($i = 0; $i -lt $obj.length; $i++) {
            if ($obj[$i] -in $exclude) {
                continue
            }
            try {
                $obj[$i] = replace-properties $obj[$i] $vars -exclude ($exclude + @($obj))
            }
            finally {
            }
        }
    }    
    elseif ($strict) {
        throw "unsupported object"
       
    }

    return $obj
    }
}

#TODO: support multiple matches per line
function _replaceVarline ([Parameter(Mandatory=$true)]$text, $vars = @{}) {
       Measure-function  "$($MyInvocation.MyCommand.Name)" {

    $r = $text
    if ($null -eq $vars) {
        throw "vars == NULL"
    }

    do {
        #each replace may insert a new variable reference in the string, so we need to iterate again
        $replaced = $false
        foreach($kvp in $vars.GetEnumerator()) {
            $name = $kvp.key
            $val = $kvp.value

            if ($r -match "\{$name\}") {
                $r = $r -replace "\{$name\}",$val
                $replaced = $true
                break
            }
            # support also same placeholder as in template match
            elseif ($r -match "__$($name)__") {
                $r = $r -replace "__$($name)__",$val
                $replaced = $true
                break
            }
            elseif ($r -match "_$($name)_") {
                $r = $r -replace "_$($name)_",$val
                $replaced = $true
                break
            }
        }    
    } while ($replaced)

    return $r    
       }
}

#TODO: support multiple matches per line
function _ReplaceVarsAuto([Parameter(Mandatory=$true)]$__text)  {
        Measure-function  "$($MyInvocation.MyCommand.Name)" {

    do {
        #each replace may insert a new variable reference in the string, so we need to iterate again
        $__replaced = $false
        $__matches = [System.Text.RegularExpressions.Regex]::Matches($__text, "\{(\?{0,1}[a-zA-Z0-9_.:]+?)\}")
        foreach($__match in $__matches) {
            if ($__match.Success) {
                $__name = $__Match.Groups[1].Value
                $__orgname = $__name
                $__defaultifnull = $false
                if ($__name.startswith("?")) {
                    $__name= $__name.substring(1)
                    $__defaultifnull = $true
                }
                $__varpath = $__name 
                $__splits = $__name.split(".")
                $__splitstart = 1
                if (!($__varpath -match ":")) {
                    if ($__varpath.startswith("vars.")) {
                        $__varpath = "variable:" + $__splits[0]                 
                    } else {
                        $__varpath = "cannot-reference-local-script-or-global-vars-without-namespace-prefix"
                    }
                }
                $__val = $null
                # this is a fragile thing. the module itself may define local vars that collide with map vars
                if (test-path "$__varpath") {
                    $__val = (get-item $__varpath).Value
                    for($__i = $__splitstart; $__i -lt $__splits.length; $__i++) {
                        $__s = $__splits[$__i] 
                        $__val = $__val.$__s
                    }  
                }
                elseif (test-path "variable:self") {
                    $__selftmp = (get-item "variable:self").Value
                    $__val = $__selftmp
                    foreach($__s in $__splits) {
                        $__val = $__val.$__s
                    }            
                }
                if ($null -ne $__val) {
                    $__text = $__text -replace "\{$([System.Text.RegularExpressions.Regex]::Escape($__orgname))\}",$__val
                    $__replaced = $true
                } 
                elseif ($__defaultifnull) {
                    $__text = $__text -replace "\{$([System.Text.RegularExpressions.Regex]::Escape($__orgname))\}",""
                    $__replaced = $true                
                }
            }
        }
    }
    while ($__replaced)
    return $__text
        }
}

function convert-vars([Parameter(Mandatory=$true)]$text, $vars = @{}, [switch][bool]$noauto = $false) {
        Measure-function  "$($MyInvocation.MyCommand.Name)" {

    $text = @($text) | % { _replaceVarline $_ $vars }

    $originalself = $self
    try {
        # is this necessary if we're doing replace-properties twice?
        if (!$noauto) {
            # _ReplaceVarsAuto uses $self global variable
            # if it is not set, use $vars as $self
            if ($null -eq $originalself) {
                $self = $vars
            }
            $text = @($text) | % { _ReplaceVarsAuto $_ }
        
            # also use $vars as $self if $self was passed
            if ($null -ne $originalself -and $vars -ne $originalself) {
                $self = $vars
                $text = @($text) | % { _ReplaceVarsAuto $_ }
            }        
        }

    
        $m = [System.Text.RegularExpressions.Regex]::Matches($text, "\{(\?{0,1}[a-zA-Z0-9_.:]+?)\}")
        if ($m.count -gt 0) {
            write-warning "missing variable '$($m[0].Groups[1].Value)'"
            if ($WarningPreference -ne "SilentlyContinue") {
                $a = 0
            }
        }
        return $text
    } finally { 
        $self = $originalself
    }
}
}

function get-vardef ($text) {
 
     Measure-function  "$($MyInvocation.MyCommand.Name)" {
   $result = $null
    $m = [System.Text.RegularExpressions.Regex]::Matches($text, "__([a-zA-Z]+)__");
    if ($m.Count -gt 0) {
        $result = $m | % {
            $_.Groups[1].Value
        }
        return $result
    }

    $m = [System.Text.RegularExpressions.Regex]::Matches($text, "_([a-zA-Z]+)_");
    if ($m.Count -gt 0) {
        $result = $m | % {
            $_.Groups[1].Value
        }
        return $result
    }

    return $null
}
}

function _MatchVarPattern ($text, $pattern) {
     Measure-function  "$($MyInvocation.MyCommand.Name)" {

    $result = $null
    $vars = get-vardef $pattern
    if ($null -eq $vars) {
        return $null 
    }
    $vars = @($vars)
    if ($vars.Length -eq 0) {
        
    }
    $regex = $pattern -replace "__[a-zA-Z]+__","([a-zA-Z0-9]*)"    
    $regex = $regex -replace "_[a-zA-Z]+_","([a-zA-Z0-9]*)"    
    $m = [System.Text.RegularExpressions.Regex]::Matches($text, "^$regex`$");
    
    if ($null -ne $m) {
        try {
            $result = $m | % {
                for($i = 1; $i -lt $_.Groups.Count; $i++) {
                    $val = $_.Groups[$i].Value
                    $name = $vars[$i-1]
                    if ($null -ne $name) {
                        return @{ $name = $val }
                    } else {
                        Write-Warning "null name in vars??"
                    }
                }
            }
        } catch {
            throw
        }
    }
    return $result
}
}

new-alias Replace-Vars Convert-Vars -force
new-alias Replace-Properties Convert-PropertiesFromVars -force