package termenv

import (
	"fmt"
	"strings"
)

const (
	CursorUpSeq              = "%dA"
	CursorDownSeq            = "%dB"
	CursorForwardSeq         = "%dC"
	CursorBackSeq            = "%dD"
	CursorNextLineSeq        = "%dE"
	CursorPreviousLineSeq    = "%dF"
	CursorHorizontalSeq      = "%dG"
	CursorPositionSeq        = "%d;%dH"
	EraseDisplaySeq          = "%dJ"
	EraseLineSeq             = "%dK"
	ScrollUpSeq              = "%dS"
	ScrollDownSeq            = "%dT"
	SaveCursorPositionSeq    = "s"
	RestoreCursorPositionSeq = "u"
	ChangeScrollingRegionSeq = "%d;%dr"
	InsertLineSeq            = "%dL"
	DeleteLineSeq            = "%dM"

	// Explicit values for EraseLineSeq.
	EraseLineRightSeq  = "0K"
	EraseLineLeftSeq   = "1K"
	EraseEntireLineSeq = "2K"

	ShowCursorSeq             = "?25h"
	HideCursorSeq             = "?25l"
	EnableMousePressSeq       = "?9h" // press only (X10)
	DisableMousePressSeq      = "?9l"
	EnableMouseSeq            = "?1000h" // press, release, wheel
	DisableMouseSeq           = "?1000l"
	EnableMouseHiliteSeq      = "?1001h" // highlight
	DisableMouseHiliteSeq     = "?1001l"
	EnableMouseCellMotionSeq  = "?1002h" // press, release, move on pressed, wheel
	DisableMouseCellMotionSeq = "?1002l"
	EnableMouseAllMotionSeq   = "?1003h" // press, release, move, wheel
	DisableMouseAllMotionSeq  = "?1003l"
	AltScreenSeq              = "?1049h"
	ExitAltScreenSeq          = "?1049l"
)

// Reset the terminal to its default style, removing any active styles.
func Reset() {
	fmt.Print(CSI + ResetSeq + "m")
}

// AltScreen switches to the alternate screen buffer. The former view can be
// restored with ExitAltScreen().
func AltScreen() {
	fmt.Print(CSI + AltScreenSeq)
}

// ExitAltScreen exits the alternate screen buffer and returns to the former
// terminal view.
func ExitAltScreen() {
	fmt.Print(CSI + ExitAltScreenSeq)
}

// ClearScreen clears the visible portion of the terminal.
func ClearScreen() {
	fmt.Printf(CSI+EraseDisplaySeq, 2)
	MoveCursor(1, 1)
}

// MoveCursor moves the cursor to a given position.
func MoveCursor(row int, column int) {
	fmt.Printf(CSI+CursorPositionSeq, row, column)
}

// HideCursor hides the cursor.
func HideCursor() {
	fmt.Printf(CSI + HideCursorSeq)
}

// ShowCursor shows the cursor.
func ShowCursor() {
	fmt.Printf(CSI + ShowCursorSeq)
}

// SaveCursorPosition saves the cursor position.
func SaveCursorPosition() {
	fmt.Print(CSI + SaveCursorPositionSeq)
}

// RestoreCursorPosition restores a saved cursor position.
func RestoreCursorPosition() {
	fmt.Print(CSI + RestoreCursorPositionSeq)
}

// CursorUp moves the cursor up a given number of lines.
func CursorUp(n int) {
	fmt.Printf(CSI+CursorUpSeq, n)
}

// CursorDown moves the cursor down a given number of lines.
func CursorDown(n int) {
	fmt.Printf(CSI+CursorDownSeq, n)
}

// CursorForward moves the cursor up a given number of lines.
func CursorForward(n int) {
	fmt.Printf(CSI+CursorForwardSeq, n)
}

// CursorBack moves the cursor backwards a given number of cells.
func CursorBack(n int) {
	fmt.Printf(CSI+CursorBackSeq, n)
}

// CursorNextLine moves the cursor down a given number of lines and places it at
// the beginning of the line.
func CursorNextLine(n int) {
	fmt.Printf(CSI+CursorNextLineSeq, n)
}

// CursorPrevLine moves the cursor up a given number of lines and places it at
// the beginning of the line.
func CursorPrevLine(n int) {
	fmt.Printf(CSI+CursorPreviousLineSeq, n)
}

// ClearLine clears the current line.
func ClearLine() {
	fmt.Print(CSI + EraseEntireLineSeq)
}

// ClearLineLeft clears the line to the left of the cursor.
func ClearLineLeft() {
	fmt.Print(CSI + EraseLineLeftSeq)
}

// ClearLineRight clears the line to the right of the cursor.
func ClearLineRight() {
	fmt.Print(CSI + EraseLineRightSeq)
}

// ClearLines clears a given number of lines.
func ClearLines(n int) {
	clearLine := fmt.Sprintf(CSI+EraseLineSeq, 2)
	cursorUp := fmt.Sprintf(CSI+CursorUpSeq, 1)
	fmt.Print(clearLine + strings.Repeat(cursorUp+clearLine, n))
}

// ChangeScrollingRegion sets the scrolling region of the terminal.
func ChangeScrollingRegion(top, bottom int) {
	fmt.Printf(CSI+ChangeScrollingRegionSeq, top, bottom)
}

// InsertLines inserts the given number of lines at the top of the scrollable
// region, pushing lines below down.
func InsertLines(n int) {
	fmt.Printf(CSI+InsertLineSeq, n)
}

// DeleteLines deletes the given number of lines, pulling any lines in
// the scrollable region below up.
func DeleteLines(n int) {
	fmt.Printf(CSI+DeleteLineSeq, n)
}

// EnableMousePress enables X10 mouse mode. Button press events are sent only.
func EnableMousePress() {
	fmt.Print(CSI + EnableMousePressSeq)
}

// DisableMousePress disables X10 mouse mode.
func DisableMousePress() {
	fmt.Print(CSI + EnableMousePressSeq)
}

// EnableMouse enables Mouse Tracking mode.
func EnableMouse() {
	fmt.Print(CSI + EnableMouseSeq)
}

// DisableMouse disables Mouse Tracking mode.
func DisableMouse() {
	fmt.Print(CSI + DisableMouseSeq)
}

// EnableMouseHilite enables Hilite Mouse Tracking mode.
func EnableMouseHilite() {
	fmt.Print(CSI + EnableMouseHiliteSeq)
}

// DisableMouseHilite disables Hilite Mouse Tracking mode.
func DisableMouseHilite() {
	fmt.Print(CSI + DisableMouseHiliteSeq)
}

// EnableMouseCellMotion enables Cell Motion Mouse Tracking mode.
func EnableMouseCellMotion() {
	fmt.Print(CSI + EnableMouseCellMotionSeq)
}

// DisableMouseCellMotion disables Cell Motion Mouse Tracking mode.
func DisableMouseCellMotion() {
	fmt.Print(CSI + DisableMouseCellMotionSeq)
}

// EnableMouseAllMotion enables All Motion Mouse mode.
func EnableMouseAllMotion() {
	fmt.Print(CSI + EnableMouseAllMotionSeq)
}

// DisableMouseAllMotion disables All Motion Mouse mode.
func DisableMouseAllMotion() {
	fmt.Print(CSI + DisableMouseAllMotionSeq)
}