package config

import (
	"fmt"
	"testing"
)

type interpolateTestCase struct {
	String   string
	Data     map[string]string
	Expected string
}

var interpolateTestCases = []interpolateTestCase{
	{
		String: "${foo}",
		Data: map[string]string{
			"foo": "bar",
		},
		Expected: "bar",
	},
	{
		String:   "${hello:-world}",
		Data:     map[string]string{},
		Expected: "world",
	},
	{
		String:   "${hello:-}",
		Data:     map[string]string{},
		Expected: "${hello:-}",
	},
	{
		String:   "foo",
		Data:     map[string]string{},
		Expected: "foo",
	},
	{
		String:   "",
		Data:     map[string]string{},
		Expected: "",
	},
}

func TestInterpolate(t *testing.T) {
	for idx, tc := range interpolateTestCases {
		func(idx int, tc interpolateTestCase) {
			t.Run(fmt.Sprintf("Case_%d", idx), func(t *testing.T) {
				result := interpolate(tc.String, func(name string) string {
					value, exists := tc.Data[name]
					if !exists {
						return ""
					}

					return value
				})

				if e, g := tc.Expected, result; e != g {
					t.Errorf("result: expected '%v', got '%v'", tc.Expected, result)
				}
			})
		}(idx, tc)
	}
}