java-commons/muscript-ast/src/main/java/io/gitlab/jfronny/muscript/ast/context/ExprUtils.java

package io.gitlab.jfronny.muscript.ast.context;

import io.gitlab.jfronny.commons.StringFormatter;
import io.gitlab.jfronny.muscript.ast.*;
import io.gitlab.jfronny.muscript.ast.bool.BoolAssign;
import io.gitlab.jfronny.muscript.ast.bool.BoolConditional;
import io.gitlab.jfronny.muscript.ast.bool.BoolLiteral;
import io.gitlab.jfronny.muscript.ast.bool.BoolUnpack;
import io.gitlab.jfronny.muscript.ast.dynamic.*;
import io.gitlab.jfronny.muscript.ast.number.NumberAssign;
import io.gitlab.jfronny.muscript.ast.number.NumberConditional;
import io.gitlab.jfronny.muscript.ast.number.NumberLiteral;
import io.gitlab.jfronny.muscript.ast.number.NumberUnpack;
import io.gitlab.jfronny.muscript.ast.string.*;

import java.util.Set;

public class ExprUtils {
    public static DynamicExpr asDynamic(Expr expression) {
        expression = unpack(expression);
        return expression instanceof DynamicExpr dynamic ? dynamic : new DynamicCoerce(expression);
    }

    public static BoolExpr asBool(Expr expression) {
        return switch (unpack(expression)) {
            case BoolExpr bool -> bool;
            case DynamicConditional(var location, var condition, var ifTrue, var ifFalse) -> new BoolConditional(location, condition, asBool(ifTrue), asBool(ifFalse));
            case DynamicAssign(var location, var left, var right) -> new BoolAssign(location, left, asBool(right));
            case DynamicExpr dynamic -> new BoolUnpack(dynamic);
            case NullLiteral nl -> throw new TypeMismatchException("Expected boolean expression but got null");
            case StringExpr string -> throw new TypeMismatchException("Expected boolean expression but got string");
            case NumberExpr number -> throw new TypeMismatchException("Expected boolean expression but got number");
        };
    }

    public static NumberExpr asNumber(Expr expression) {
        return switch (unpack(expression)) {
            case NumberExpr number -> number;
            case DynamicConditional(var location, var condition, var ifTrue, var ifFalse) -> new NumberConditional(location, condition, asNumber(ifTrue), asNumber(ifFalse));
            case DynamicAssign(var location, var left, var right) -> new NumberAssign(location, left, asNumber(right));
            case DynamicExpr dynamic -> new NumberUnpack(dynamic);
            case NullLiteral nl -> throw new TypeMismatchException("Expected number expression but got null");
            case StringExpr string -> throw new TypeMismatchException("Expected number expression but got string");
            case BoolExpr bool -> throw new TypeMismatchException("Expected number expression but got boolean");
        };
    }

    public static StringExpr asString(Expr expression) {
        return switch (unpack(expression)) {
            case StringExpr string -> string;
            case NumberLiteral number -> new StringLiteral(expression.location(), StringFormatter.toStringPrecise(number.value()));
            case BoolLiteral bool -> new StringLiteral(expression.location(), bool.value() ? "true" : "false");
            case NullLiteral nl -> new StringLiteral(expression.location(), "null");
            case DynamicConditional(var location, var condition, var ifTrue, var ifFalse) -> new StringConditional(location, condition, asString(ifTrue), asString(ifFalse));
            case BoolConditional(var location, var condition, var ifTrue, var ifFalse) -> new StringConditional(location, condition, asString(ifTrue), asString(ifFalse));
            case NumberConditional(var location, var condition, var ifTrue, var ifFalse) -> new StringConditional(location, condition, asString(ifTrue), asString(ifFalse));
            case DynamicAssign(var location, var left, var right) -> new StringAssign(location, left, asString(right));
            case DynamicExpr dynamic -> new StringUnpack(dynamic);
            default -> new StringCoerce(expression);
        };
    }

    public static Expr unpack(Expr expression) {
        return switch (expression) {
            case null -> throw new NullPointerException();
            case BoolUnpack(var inner) -> unpack(inner);
            case NumberUnpack(var inner) -> unpack(inner);
            case StringUnpack(var inner) -> unpack(inner);
            case DynamicCoerce(var inner) -> unpack(inner);
            case StringCoerce(var inner) -> unpack(inner);
            default -> expression;
        };
    }

    private static final Set<String> allowedVariables = Set.of("date", "time", "enum", "listOf");
    public static boolean isDirect(Expr expr) {
        return switch (expr) {
            case NullLiteral ignored -> true;
            case StringLiteral ignored -> true;
            case NumberLiteral ignored -> true;
            case BoolLiteral ignored -> true;
            case DynamicLiteral(var location, var value) -> value.isDirect();
            case DynamicCoerce(var inner) -> isDirect(inner);
            case ObjectLiteral(var location, var content) -> content.values().stream().allMatch(ExprUtils::isDirect);
            case Concatenate(var location, var left, var right) -> isDirect(left) && isDirect(right);
            case BoolUnpack(var inner) -> isDirect(inner);
            case NumberUnpack(var inner) -> isDirect(inner);
            case StringUnpack(var inner) -> isDirect(inner);
            case Bind(var location, var callable, var parameter) -> isDirect(callable) && isDirect(parameter);
            case Call(var location, var left, var args) -> isDirect(left) && args.stream().allMatch(a -> !a.variadic() && isDirect(a.value()));
            case Variable(var location, var name) -> allowedVariables.contains(name);
            default -> false;
        };
    }
}