package feathercalculator

import uk.co.nickthecoder.feather.core.*
import java.lang.reflect.*
import uk.co.nickthecoder.featureful.Scripts

class FeatherCalculatorBehaviour : TextBehaviour( "Calc" ) {

    val clear = Action( "Clear", this:>clearAll )
        .icon( "clean" ).description( "Clear : Ctrl+A then Ctrl+X" )

    val eval = Action( "=", this:>eval )
        .shortcut( FeatherCalculator.evalShortcut )
        .description( "Evaluates the current line, or the selected block of text" )

    override meth toolbar() = listOf<Feature>(
        clear, spacer, eval, spacer
    )

    init {
        append( "// Type an expression, then press Ctrl+ENTER to evaluate the current line.\n" )
        append( "// Or select a block of text, then press Ctrl+ENTER to evaluate the block.\n" )
        append( "// Variables are not remembered from one calculation to the next.\n" )
    }

    meth clearAll() {
        clear()
    }

    meth eval() {
        val selection = selection()

        val toEvaluate = if ( selection.selection == "" ) {
            line(selection.fromRow)
        } else {
            selection.selection
        }
        val insertAtRow = selection.toRow
        val insertAtColumn = if (selection.selection == "") {
            line(selection.fromRow).size()
        } else {
            selection.toColumn
        }

        val config = Scripts.configuration()
        val compiler = FeatherCompiler( config )
        val script = """
class Repl {
    func eval() = if (true) {
        ${toEvaluate}
    } else {
        null
    }
}
"""
        try {
            val results = compiler.compile( StringFeatherScript( script, "FROM_STRING" ) )
            //println( "Results" )
            val klass = results.classLoader.loadClass( "Repl" )
            //println( "klass = $klass" )
            val methods = klass.getMethods()
            for (method in methods) {
                if (method.name == "eval") {
                    val result = method.invoke( null )
                    insertResult( result, insertAtRow, insertAtColumn )
                }
            }
        } catch (e : Exception) {
            // Make this a status message
            println( "ERROR : $e" )
        }        
    }

    meth insertResult( result : Object, row : int, column : int ) {
        if (result == null) return

        val toInsert = if ( result is String ) {
            "\n\"$result\"\n"
        } else {
            "\n$result\n"
        }

        insert( row, column, toInsert )
    }

}