package core

import (
	"git.urbach.dev/cli/q/src/errors"
	"git.urbach.dev/cli/q/src/eval"
	"git.urbach.dev/cli/q/src/expression"
	"git.urbach.dev/cli/q/src/token"
	"git.urbach.dev/cli/q/src/types"
)

// EvaluateCall evaluates a function call.
func (f *Function) EvaluateCall(expr *expression.Expression) (eval.Value, error) {
	if expr.Children[0].Token.Kind == token.Identifier {
		nameNode := expr.Children[0]
		name := nameNode.String(f.File.Bytes)
		typ := types.ByName(name, f.Package, f.All.Structs)

		if typ != nil {
			if len(expr.Children) != 2 {
				return nil, errors.New(&errors.ParameterCountMismatch{Function: name, Count: len(expr.Children), ExpectedCount: 1}, f.File, nameNode.Token.End())
			}

			value, err := f.Evaluate(expr.Children[1])

			if err != nil {
				return nil, err
			}

			switch value := value.(type) {
			case *eval.Register:
				if value.IsAlive() {
					value = &eval.Register{
						Typ:      typ,
						Register: value.Register,
						Alive:    value.Alive,
					}

					return value, nil
				}

				value.Typ = typ
			case *eval.Number:
				value.Typ = typ
			case *eval.Memory:
				value.Typ = typ
			case *eval.Label:
				value.Typ = typ
			}

			return value, nil
		}
	}

	typ, err := f.CompileCall(expr)

	if err != nil {
		return nil, err
	}

	value := &eval.Register{Register: f.CPU.Output[0]}

	if len(typ) > 0 {
		value.Typ = typ[0]
	}

	return value, nil
}