package go_environment

import (
	"os"
	"testing"
)

func TestReplaceEnvironmentVariables(t *testing.T) {
	testCases := []struct {
		input       string
		environment map[string]string
		expected    string
	}{
		{},
		{
			input:       "a",
			environment: map[string]string{},
			expected:    "a",
		},
		{
			input:       "%testVar1%",
			environment: map[string]string{},
			expected:    "%testVar1%",
		},
		{
			input: "%testVar1%",
			environment: map[string]string{
				"testVar1": "b",
			},
			expected: "b",
		},
		{
			input: "%testVar1%&%testVar1%",
			environment: map[string]string{
				"testVar1": "b",
			},
			expected: "b&b",
		},
		{
			input:       "%testVar1%&%testVar2%",
			environment: map[string]string{},
			expected:    "%testVar1%&%testVar2%",
		},
		{
			input: "%testVar1%&%testVar2%",
			environment: map[string]string{
				"testVar1": "b",
			},
			expected: "b&%testVar2%",
		},
		{
			input: "%testVar2%&%testVar1%",
			environment: map[string]string{
				"testVar1": "b",
			},
			expected: "%testVar2%&b",
		},
		{
			input:       "$(testVar1)",
			environment: map[string]string{},
			expected:    "$(testVar1)",
		},
		{
			input: "$(testVar1)",
			environment: map[string]string{
				"testVar1": "b",
			},
			expected: "b",
		},
		{
			input: "$(testVar1)&$(testVar1)",
			environment: map[string]string{
				"testVar1": "b",
			},
			expected: "b&b",
		},
		{
			input:       "$(testVar1)&$(testVar2)",
			environment: map[string]string{},
			expected:    "$(testVar1)&$(testVar2)",
		},
		{
			input: "$(testVar1)&$(testVar2)",
			environment: map[string]string{
				"testVar1": "b",
			},
			expected: "b&$(testVar2)",
		},
		{
			input: "$(testVar2)&$(testVar1)",
			environment: map[string]string{
				"testVar1": "b",
			},
			expected: "$(testVar2)&b",
		},
	}

	for i, testCase := range testCases {
		for key, value := range testCase.environment {
			os.Setenv(key, value)
		}

		if result := ReplaceEnvironmentVariables(testCase.input); result != testCase.expected {
			t.Errorf("TestReplaceEnvironmentVariables: test case %d: expected '%s' but got '%s'", i+1, testCase.expected, result)
		}

		for key := range testCase.environment {
			os.Unsetenv(key)
		}
	}
}