package io

import (
	"testing"

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

// --- MockMedium Tests ---

func TestNewMockMedium(t *testing.T) {
	m := NewMockMedium()
	assert.NotNil(t, m)
	assert.NotNil(t, m.Files)
	assert.NotNil(t, m.Dirs)
	assert.Empty(t, m.Files)
	assert.Empty(t, m.Dirs)
}

func TestMockMedium_Read(t *testing.T) {
	t.Run("reads existing file", func(t *testing.T) {
		m := NewMockMedium()
		m.Files["test.txt"] = "hello world"
		content, err := m.Read("test.txt")
		assert.NoError(t, err)
		assert.Equal(t, "hello world", content)
	})

	t.Run("returns error for non-existent file", func(t *testing.T) {
		m := NewMockMedium()
		_, err := m.Read("nonexistent.txt")
		assert.Error(t, err)
	})
}

func TestMockMedium_Write(t *testing.T) {
	m := NewMockMedium()
	err := m.Write("test.txt", "content")
	assert.NoError(t, err)
	assert.Equal(t, "content", m.Files["test.txt"])

	// Overwrite existing file
	err = m.Write("test.txt", "new content")
	assert.NoError(t, err)
	assert.Equal(t, "new content", m.Files["test.txt"])
}

func TestMockMedium_EnsureDir(t *testing.T) {
	m := NewMockMedium()
	err := m.EnsureDir("/path/to/dir")
	assert.NoError(t, err)
	assert.True(t, m.Dirs["/path/to/dir"])
}

func TestMockMedium_IsFile(t *testing.T) {
	m := NewMockMedium()
	m.Files["exists.txt"] = "content"

	assert.True(t, m.IsFile("exists.txt"))
	assert.False(t, m.IsFile("nonexistent.txt"))
}

func TestMockMedium_FileGet(t *testing.T) {
	m := NewMockMedium()
	m.Files["test.txt"] = "content"
	content, err := m.FileGet("test.txt")
	assert.NoError(t, err)
	assert.Equal(t, "content", content)
}

func TestMockMedium_FileSet(t *testing.T) {
	m := NewMockMedium()
	err := m.FileSet("test.txt", "content")
	assert.NoError(t, err)
	assert.Equal(t, "content", m.Files["test.txt"])
}

// --- Wrapper Function Tests ---

func TestRead(t *testing.T) {
	m := NewMockMedium()
	m.Files["test.txt"] = "hello"
	content, err := Read(m, "test.txt")
	assert.NoError(t, err)
	assert.Equal(t, "hello", content)
}

func TestWrite(t *testing.T) {
	m := NewMockMedium()
	err := Write(m, "test.txt", "hello")
	assert.NoError(t, err)
	assert.Equal(t, "hello", m.Files["test.txt"])
}

func TestEnsureDir(t *testing.T) {
	m := NewMockMedium()
	err := EnsureDir(m, "/my/dir")
	assert.NoError(t, err)
	assert.True(t, m.Dirs["/my/dir"])
}

func TestIsFile(t *testing.T) {
	m := NewMockMedium()
	m.Files["exists.txt"] = "content"

	assert.True(t, IsFile(m, "exists.txt"))
	assert.False(t, IsFile(m, "nonexistent.txt"))
}

func TestCopy(t *testing.T) {
	t.Run("copies file between mediums", func(t *testing.T) {
		source := NewMockMedium()
		dest := NewMockMedium()
		source.Files["test.txt"] = "hello"
		err := Copy(source, "test.txt", dest, "test.txt")
		assert.NoError(t, err)
		assert.Equal(t, "hello", dest.Files["test.txt"])
	})

	t.Run("copies to different path", func(t *testing.T) {
		source := NewMockMedium()
		dest := NewMockMedium()
		source.Files["original.txt"] = "content"
		err := Copy(source, "original.txt", dest, "copied.txt")
		assert.NoError(t, err)
		assert.Equal(t, "content", dest.Files["copied.txt"])
	})

	t.Run("returns error for non-existent source", func(t *testing.T) {
		source := NewMockMedium()
		dest := NewMockMedium()
		err := Copy(source, "nonexistent.txt", dest, "dest.txt")
		assert.Error(t, err)
	})
}

// --- Local Global Tests ---

func TestLocalGlobal(t *testing.T) {
	// io.Local should be initialized by init()
	assert.NotNil(t, Local, "io.Local should be initialized")

	// Should be able to use it as a Medium
	var m Medium = Local
	assert.NotNil(t, m)
}