package tokenize

import (
	"fmt"
	"testing"
)

func ExampleCursor_move() {
	c := Cursor{}
	fmt.Printf("after initialization    : %s\n", c)
	fmt.Printf("after 'some words'      : %s\n", c.move("some words"))
	fmt.Printf("after '\\n'              : %s\n", c.move("\n"))
	fmt.Printf("after '\\r\\nskip\\nlines' : %s\n", c.move("\r\nskip\nlines"))

	// Output:
	// after initialization    : start of file
	// after 'some words'      : line 1, column 11
	// after '\n'              : line 2, column 1
	// after '\r\nskip\nlines' : line 4, column 6
}

func ExampleCursor_String() {
	c := Cursor{}
	fmt.Println(c.String())

	c.move("\nfoobar")
	fmt.Println(c.String())

	// Output:
	// start of file
	// line 2, column 7
}

func TestGivenCursor_WhenMoving_CursorIsUpdated(t *testing.T) {
	for _, test := range []struct {
		name   string
		input  []string
		byte   int
		rune   int
		line   int
		column int
	}{
		{"No input at all", []string{""}, 0, 0, 0, 0},
		{"One ASCII char", []string{"a"}, 1, 1, 0, 1},
		{"Multiple ASCII chars", []string{"abc"}, 3, 3, 0, 3},
		{"One newline", []string{"\n"}, 1, 1, 1, 0},
		{"Carriage return", []string{"\r\r\r"}, 3, 3, 0, 3},
		{"One UTF8 3 byte char", []string{"⌘"}, 3, 1, 0, 1},
		{"Mixture", []string{"Hello\n\npretty\nW⌘O⌘R⌘L⌘D"}, 31, 23, 3, 9},
		{"Multiple calls", []string{"hello", "world"}, 10, 10, 0, 10},
	} {
		c := Cursor{}
		for _, s := range test.input {
			c.move(s)
		}
		if c.Byte != test.byte {
			t.Errorf("[%s] Unexpected byte offset %d (expected %d)", test.name, c.Byte, test.byte)
		}
		if c.Rune != test.rune {
			t.Errorf("[%s] Unexpected rune offset %d (expected %d)", test.name, c.Rune, test.rune)
		}
		if c.Line != test.line {
			t.Errorf("[%s] Unexpected line offset %d (expected %d)", test.name, c.Line, test.line)
		}
		if c.Column != test.column {
			t.Errorf("[%s] Unexpected column offset %d (expected %d)", test.name, c.Column, test.column)
		}
	}
}