// helpers_test.go
package expr

import (
	"fmt"
	"testing"
)

func subtract(ctx ExprContext, name string, args []any) (result any, err error) {
	if len(args) != 2 {
		err = fmt.Errorf("%s(): requires exactly two arguments", name)
		return
	}
	x, xok := args[0].(int64)
	y, yok := args[1].(int64)
	if xok && yok {
		result = x - y
	} else {
		err = fmt.Errorf("expected integer (int64) arguments, got %T and %T values", x, y)
	}
	return
}

func TestEvalStringA(t *testing.T) {

	source := `a + b * subtract(4,2)`
	args := []EvalArg{
		{"a", uint8(1)},
		{"b", int8(2)},
		{"subtract", FuncTemplate(subtract)},
		// force coverage
		{"a16", uint16(1)},
		{"b16", int16(2)},
		{"a32", uint32(1)},
		{"b32", int32(2)},
		{"a64", uint64(1)},
		{"b64", int64(2)},
		{"f32", float32(1.0)},
		{"f64", float64(1.0)},
	}

	wantResult := int64(5)
	gotResult, gotErr := EvalStringA(source, args...)
	if value, ok := gotResult.(int64); ok && value != wantResult {
		t.Errorf("Source %q got %v, want %v", source, gotResult, wantResult)
		t.Errorf("Error: %v", gotErr)
	}
	fmt.Println("Hello World!")
}

func TestEvalString(t *testing.T) {

	ctx := NewSimpleVarStore()
	ctx.SetVar("a", uint8(1))
	ctx.SetVar("b", int8(2))
	ctx.SetVar("f", 2.0)
	// force coverage
	ctx.SetVar("a16", uint16(1))
	ctx.SetVar("b16", int16(2))
	ctx.SetVar("a32", uint32(1))
	ctx.SetVar("b32", int32(2))
	ctx.SetVar("a64", uint64(1))
	ctx.SetVar("b64", int64(2))
	ctx.SetVar("f32", float32(1.0))
	ctx.SetVar("f64", float64(1.0))

	// force coverage
	ctx.GetFuncInfo("dummy")
	ctx.Call("dummy", []any{})

	source := `a + b * f`

	wantResult := float64(5)
	gotResult, gotErr := EvalString(ctx, source)
	if value, ok := gotResult.(float64); ok && value != wantResult {
		t.Errorf("Source %q got %v, want %v", source, gotResult, wantResult)
		t.Errorf("Error: %v", gotErr)
	}
	fmt.Println("Hello World!")
}