package buffer_test

import (
	"fmt"

	"rickub.com/turbo-editors/turbo-core/buffer"
)

// Typing into a buffer and reading the result back.
func ExampleBuffer_Insert() {
	b := buffer.New()
	b.Insert("package main")
	b.InsertNewlineAndIndent()
	b.Insert("\nfunc main() {}")

	fmt.Println(b.Text())
	// Output:
	// package main
	//
	// func main() {}
}

// A run of typed characters is one undo step, not one per keystroke.
func ExampleBuffer_Undo() {
	b := buffer.NewFromString("var ")
	b.MoveBufferEnd()
	for _, r := range "count" {
		b.InsertRune(r)
	}
	fmt.Println(b.Text())

	b.Undo()
	fmt.Println(b.Text())
	// Output:
	// var count
	// var
}

// Selecting a span and replacing it in one go.
func ExampleBuffer_SelectedText() {
	b := buffer.NewFromString("hello world")
	b.SetCursor(buffer.Position{Line: 0, Col: 6})
	b.StartSelection()
	b.Extend(b.MoveLineEnd)

	fmt.Println(b.SelectedText())

	b.Insert("gophers")
	fmt.Println(b.Text())
	// Output:
	// world
	// hello gophers
}

// Tabs occupy several screen columns, so rune columns and screen columns are
// not the same thing.
func ExampleBuffer_DisplayColumn() {
	b := buffer.NewFromString("\tif err != nil {")
	b.SetTabWidth(4)

	fmt.Println(b.DisplayColumn(0, 1)) // just after the tab
	fmt.Println(b.RuneColumn(0, 4))    // back from the screen column
	// Output:
	// 4
	// 1
}