package common

import (
    "testing"

    "github.com/stretchr/testify/assert"
)

func TestNewStringFlag(t *testing.T) {
    tests := []struct {
        name         string
        defaultValue string
        expected     string
    }{
        {
            name:         "empty default",
            defaultValue: "",
            expected:     "",
        },
        {
            name:         "non-empty default",
            defaultValue: "default",
            expected:     "default",
        },
    }

    for _, tt := range tests {
        t.Run(tt.name, func(t *testing.T) {
            flag := NewStringFlag(tt.defaultValue)

            // Check initial state
            assert.Equal(t, tt.expected, flag.Value(), "Value should match default")
            assert.False(t, flag.WasExplicitlySet(), "New flag should not be marked as explicitly set")
        })
    }
}

func TestStringFlag_Set(t *testing.T) {
    tests := []struct {
        name         string
        defaultValue string
        setValue     string
        expected     string
    }{
        {
            name:         "empty default, set value",
            defaultValue: "",
            setValue:     "new value",
            expected:     "new value",
        },
        {
            name:         "non-empty default, set empty",
            defaultValue: "default",
            setValue:     "",
            expected:     "",
        },
        {
            name:         "non-empty default, set new value",
            defaultValue: "default",
            setValue:     "new value",
            expected:     "new value",
        },
    }

    for _, tt := range tests {
        t.Run(tt.name, func(t *testing.T) {
            flag := NewStringFlag(tt.defaultValue)

            // Set the value
            flag.Set(tt.setValue)

            // Check state after setting
            assert.Equal(t, tt.expected, flag.Value(), "Value should match set value")
            assert.True(t, flag.WasExplicitlySet(), "Flag should be marked as explicitly set")
        })
    }
}

func TestStringFlag_MultipleSet(t *testing.T) {
    flag := NewStringFlag("initial")

    // Initial state
    assert.Equal(t, "initial", flag.Value())
    assert.False(t, flag.WasExplicitlySet())

    // First set
    flag.Set("first")
    assert.Equal(t, "first", flag.Value())
    assert.True(t, flag.WasExplicitlySet())

    // Second set
    flag.Set("second")
    assert.Equal(t, "second", flag.Value())
    assert.True(t, flag.WasExplicitlySet(), "Flag should remain explicitly set")
}

func TestStringFlag_Implementation(t *testing.T) {
    // Test that stringFlag properly implements StringFlag interface
    var _ StringFlag = &stringFlag{}
}