private static String createSourceCodeErrorMessage()

in freemarker-core/src/main/java/freemarker/core/JSONParser.java [511:589]
77 lines of code
20 McCabe index (conditional complexity)

    private static String createSourceCodeErrorMessage(String message, String srcCode, int position) {
        int ln = srcCode.length();
        if (position < 0) {
            position = 0;
        }
        if (position >= ln) {
            return message + "\n"
                    + "Error location: At the end of text.";
        }

        int i;
        char c;
        int rowBegin = 0;
        int rowEnd;
        int row = 1;
        char lastChar = 0;
        for (i = 0; i <= position; i++) {
            c = srcCode.charAt(i);
            if (lastChar == 0xA) {
                rowBegin = i;
                row++;
            } else if (lastChar == 0xD && c != 0xA) {
                rowBegin = i;
                row++;
            }
            lastChar = c;
        }
        for (i = position; i < ln; i++) {
            c = srcCode.charAt(i);
            if (c == 0xA || c == 0xD) {
                if (c == 0xA && i > 0 && srcCode.charAt(i - 1) == 0xD) {
                    i--;
                }
                break;
            }
        }
        rowEnd = i - 1;
        if (position > rowEnd + 1) {
            position = rowEnd + 1;
        }
        int col = position - rowBegin + 1;
        if (rowBegin > rowEnd) {
            return message + "\n"
                    + "Error location: line "
                    + row + ", column " + col + ":\n"
                    + "(Can't show the line because it is empty.)";
        }
        String s1 = srcCode.substring(rowBegin, position);
        String s2 = srcCode.substring(position, rowEnd + 1);
        s1 = expandTabs(s1, 8);
        int ln1 = s1.length();
        s2 = expandTabs(s2, 8, ln1);
        int ln2 = s2.length();
        if (ln1 + ln2 > MAX_QUOTATION_LENGTH) {
            int newLn2 = ln2 - ((ln1 + ln2) - MAX_QUOTATION_LENGTH);
            if (newLn2 < 6) {
                newLn2 = 6;
            }
            if (newLn2 < ln2) {
                s2 = s2.substring(0, newLn2 - 3) + "...";
                ln2 = newLn2;
            }
            if (ln1 + ln2 > MAX_QUOTATION_LENGTH) {
                s1 = "..." + s1.substring((ln1 + ln2) - MAX_QUOTATION_LENGTH + 3);
            }
        }
        StringBuilder res = new StringBuilder(message.length() + 80);
        res.append(message);
        res.append("\nError location: line ").append(row).append(", column ").append(col).append(":\n");
        res.append(s1).append(s2).append("\n");
        int x = s1.length();
        while (x != 0) {
            res.append(' ');
            x--;
        }
        res.append('^');

        return res.toString();
    }