package net.sergeych.ling

import kotlin.math.*

class Script(
    override val pos: Pos,
    private val statements: List<Statement> = emptyList(),
) : Statement() {

    override suspend fun execute(context: Context): Obj {
        // todo: run script
        println("exec script in $context <- ${context.parent}")
        var lastResult: Obj = ObjVoid
        for (s in statements) {
            lastResult = s.execute(context)
        }
        return lastResult
    }

    suspend fun execute() = execute(defaultContext.copy())

    companion object {
        val defaultContext: Context = Context(null).apply {
            addFn("println") {
                print("yn: ")
                for( (i,a) in args.withIndex() ) {
                    if( i > 0 ) print(' ' + a.asStr.value)
                    else print(a.asStr.value)
                }
                println()
                ObjVoid
            }
            addFn("floor") {
                val x = args.firstAndOnly()
                if( x is ObjInt ) x
                else ObjReal(floor(x.toDouble()))
            }
            addFn("ceil") {
                val x = args.firstAndOnly()
                if( x is ObjInt ) x
                else ObjReal(ceil(x.toDouble()))
            }
            addFn("round") {
                val x = args.firstAndOnly()
                if( x is ObjInt ) x
                else ObjReal(round(x.toDouble()))
            }
            addFn("sin") {
                sin(args.firstAndOnly().toDouble())
            }
            val pi = ObjReal(PI)
            addConst(pi, "π")
            getOrCreateNamespace("Math").also { ns ->
                ns.addConst(pi, "PI")
            }
        }
    }
}