package com.termux.terminal;

/**
 * ${CSI}${top};${bottom}r" - set Scrolling Region [top;bottom] (default = full size of window) (DECSTBM).
 * <p/>
 * "DECSTBM moves the cursor to column 1, line 1 of the page" (http://www.vt100.net/docs/vt510-rm/DECSTBM).
 */
public class ScrollRegionTest extends TerminalTestCase {

    public void testScrollRegionTop() {
        withTerminalSized(3, 4).enterString("111222333444").assertLinesAre("111", "222", "333", "444");
        enterString("\033[2r").assertCursorAt(0, 0);
        enterString("\r\n\r\n\r\n\r\nCDEFGH").assertLinesAre("111", "444", "CDE", "FGH").assertHistoryStartsWith("333");
        enterString("IJK").assertLinesAre("111", "CDE", "FGH", "IJK").assertHistoryStartsWith("444");
        // Reset scroll region and enter line:
        enterString("\033[r").enterString("\r\n\r\n\r\n").enterString("LMNOPQ").assertLinesAre("CDE", "FGH", "LMN", "OPQ");
    }

    public void testScrollRegionBottom() {
        withTerminalSized(3, 4).enterString("111222333444");
        assertLinesAre("111", "222", "333", "444");
        enterString("\033[1;3r").assertCursorAt(0, 0);
        enterString("\r\n\r\nCDEFGH").assertLinesAre("222", "CDE", "FGH", "444").assertHistoryStartsWith("111");
        // Reset scroll region and enter line:
        enterString("\033[r").enterString("\r\n\r\n\r\n").enterString("IJKLMN").assertLinesAre("CDE", "FGH", "IJK", "LMN");
    }

    public void testScrollRegionResetWithOriginMode() {
        withTerminalSized(3, 4).enterString("111222333444");
        assertLinesAre("111", "222", "333", "444");
        // "\033[?6h" sets origin mode, so that the later DECSTBM resets cursor to below margin:
        enterString("\033[?6h\033[2r").assertCursorAt(1, 0);
    }

    public void testScrollRegionLeft() {
        // ${CSI}?69h for DECLRMM enabling, ${CSI}${LEFTMARGIN};${RIGHTMARGIN}s for DECSLRM margin setting.
        withTerminalSized(3, 3).enterString("\033[?69h\033[2sABCDEFG").assertLinesAre("ABC", " DE", " FG");
        enterString("HI").assertLinesAre("ADE", " FG", " HI").enterString("JK").assertLinesAre("AFG", " HI", " JK");
        enterString("\n").assertLinesAre("AHI", " JK", "   ");
    }

    public void testScrollRegionRight() {
        // ${CSI}?69h for DECLRMM enabling, ${CSI}${LEFTMARGIN};${RIGHTMARGIN}s for DECSLRM margin setting.
        withTerminalSized(3, 3).enterString("YYY\033[?69h\033[1;2sABCDEF").assertLinesAre("ABY", "CD ", "EF ");
        enterString("GH").assertLinesAre("CDY", "EF ", "GH ").enterString("IJ").assertLinesAre("EFY", "GH ", "IJ ");
        enterString("\n").assertLinesAre("GHY", "IJ ", "   ");
    }

    public void testScrollRegionOnAllSides() {
        // ${CSI}?69h for DECLRMM enabling, ${CSI}${LEFTMARGIN};${RIGHTMARGIN}s for DECSLRM margin setting.
        withTerminalSized(4, 4).enterString("ABCDEFGHIJKLMNOP").assertLinesAre("ABCD", "EFGH", "IJKL", "MNOP");
        // http://www.vt100.net/docs/vt510-rm/DECOM
        enterString("\033[?6h\033[2;3r").assertCursorAt(1, 0);
        enterString("\033[?69h\033[2;3s").assertCursorAt(1, 1);
        enterString("QRST").assertLinesAre("ABCD", "EQRH", "ISTL", "MNOP");
        enterString("UV").assertLinesAre("ABCD", "ESTH", "IUVL", "MNOP");
    }

    public void testDECCOLMResetsScrollMargin() {
        // DECCOLM — Select 80 or 132 Columns per Page (http://www.vt100.net/docs/vt510-rm/DECCOLM) has the important
        // side effect to clear scroll margins, which is useful for e.g. the "reset" utility to clear scroll margins.
        withTerminalSized(3, 4).enterString("111222333444").assertLinesAre("111", "222", "333", "444");
        enterString("\033[2r\033[?3h\r\nABCDEFGHIJKL").assertLinesAre("ABC", "DEF", "GHI", "JKL");
    }

    public void testScrollOutsideVerticalRegion() {
        withTerminalSized(3, 4).enterString("\033[0;2rhi\033[4;0Hyou").assertLinesAre("hi ", "   ", "   ", "you");
        //enterString("see").assertLinesAre("hi ", "   ", "   ", "see");
    }

    public void testNELRespectsLeftMargin() {
        // vttest "Menu 11.3.2: VT420 Cursor-Movement Test", select "10. Test other movement (CR/HT/LF/FF) within margins".
        // The NEL (ESC E) sequence moves cursor to first position on next line, where first position depends on origin mode and margin.
        withTerminalSized(3, 3).enterString("\033[?69h\033[2sABC\033ED").assertLinesAre("ABC", "D  ", "   ");
        withTerminalSized(3, 3).enterString("\033[?69h\033[2sABC\033[?6h\033ED").assertLinesAre("ABC", " D ", "   ");
    }

    public void testBackwardIndex() {
        // vttest "Menu 11.3.2: VT420 Cursor-Movement Test", test 7.
        // Without margins:
        withTerminalSized(3, 3).enterString("ABCDEF\0336H").assertLinesAre("ABC", "DHF", "   ");
        enterString("\0336\0336I").assertLinesAre("ABC", "IHF", "   ");
        enterString("\0336\0336").assertLinesAre(" AB", " IH", "   ");
        // With left margin:
        withTerminalSized(3, 3).enterString("\033[?69h\033[2sABCDEF\0336\0336").assertLinesAre("A B", "  D", "  F");
    }

    public void testForwardIndex() {
        // vttest "Menu 11.3.2: VT420 Cursor-Movement Test", test 8.
        // Without margins:
        withTerminalSized(3, 3).enterString("ABCD\0339E").assertLinesAre("ABC", "D E", "   ");
        enterString("\0339").assertLinesAre("BC ", " E ", "   ");
        // With right margin:
        withTerminalSized(3, 3).enterString("\033[?69h\033[0;2sABCD\0339").assertLinesAre("B  ", "D  ", "   ");
    }

    public void testScrollDownWithScrollRegion() {
        withTerminalSized(2, 5).enterString("1\r\n2\r\n3\r\n4\r\n5").assertLinesAre("1 ", "2 ", "3 ", "4 ", "5 ");
        enterString("\033[3r").enterString("\033[2T").assertLinesAre("1 ", "2 ", "  ", "  ", "3 ");
    }

    public void testScrollDownBelowScrollRegion() {
        withTerminalSized(2, 5).enterString("1\r\n2\r\n3\r\n4\r\n5").assertLinesAre("1 ", "2 ", "3 ", "4 ", "5 ");
        // DECSTBM margins.
        enterString("\033[1;3r");
        // Place cursor just below bottom margin.
        enterString("\033[4;1H");
        enterString("QQ\r\nRR\r\n\r\n\r\nYY");
        assertLinesAre("1 ", "2 ", "3 ", "QQ", "YY");
    }

    /**
     * See https://github.com/termux/termux-app/issues/1340
     */
    public void testScrollRegionDoesNotLimitCursorMovement() {
        withTerminalSized(6, 4).enterString("\033[4;7r\033[3;1Haaa\033[Axxx").assertLinesAre("      ", "   xxx", "aaa   ", "      ");
        withTerminalSized(6, 4).enterString("\033[1;3r\033[3;1Haaa\033[Bxxx").assertLinesAre("      ", "      ", "aaa   ", "   xxx");
    }
}
