# Copyright (C) 2021 Free Software Foundation, Inc.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

# Create a TUI window in Python that responds to GDB event.  Each
# event will trigger the TUI window to redraw itself.
#
# This test is checking how GDB behaves if the user first displays a
# Python based tui window, and then does 'tui disable'.  At one point
# it was possible that GDB would try to redraw the tui window even
# though the tui should be disabled.

load_lib gdb-python.exp
tuiterm_env

standard_testfile

if {[build_executable "failed to prepare" ${testfile} ${srcfile}] == -1} {
    return -1
}

# Copy the Python script to where the tests are being run.
set remote_python_file [gdb_remote_download host \
			    ${srcdir}/${subdir}/${testfile}.py]

proc clean_restart_and_setup { prefix } {
    global testfile
    global remote_python_file

    with_test_prefix $prefix {

	Term::clean_restart 24 80 $testfile

	# Skip all tests if Python scripting is not enabled.
	if { [skip_python_tests] } { return 0 }

	# Now source the python script.
	gdb_test_no_output "source ${remote_python_file}" \
	    "source ${testfile}.py"

	# Create a new layout making use of our new event window.
	gdb_test_no_output "tui new-layout test events 1 cmd 1"

	# Disable source code highlighting.
	gdb_test_no_output "set style sources off"

	if {![runto_main]} {
	    perror "test suppressed"
	    return
	}
    }

    return 1
}

# Run the test.  CLEANUP_PROPERLY is either true or false.  This is
# used to set a flag in the Python code which controls whether the
# Python TUI window cleans up properly or not.
#
# When the Python window does not cleanup properly then it retains a
# cyclic reference to itself, this means that it is still possible for
# the object to try and redraw itself even when the tui is disabled.
proc run_test { cleanup_properly } {

    if { ![clean_restart_and_setup "initial restart"] } {
	unsupported "couldn't restart GDB"
	return
    }

    if { $cleanup_properly } {
	gdb_test_no_output "python cleanup_properly = True"
    } else {
	gdb_test_no_output "python cleanup_properly = False"
    }

    if {![Term::enter_tui]} {
	unsupported "TUI not supported"
	return
    }

    Term::command "layout test"

    # Confirm that the events box is initially empty, then perform two
    # actions that will add two events to the window.
    Term::check_box_contents "no events yet" 0 0 80 16 ""
    Term::command "next"
    Term::check_box_contents "single stop event" 0 0 80 16 "stop"
    Term::command "next"
    Term::check_box_contents "two stop events" 0 0 80 16 \
	"stop\[^\n\]+\nstop"

    # Now disable the tui, we should end up back at a standard GDB prompt.
    Term::command "tui disable"

    # Do something just so we know that the CLI is working.
    gdb_test "print 1 + 1 + 1" " = 3"

    # Now perform an action that would trigger an event.  At one point
    # there was a bug where the TUI window might try to redraw itself.
    # This is why we use GDB_TEST_MULTIPLE here, so we can spot the tui
    # window title and know that things have gone wrong.
    gdb_test_multiple "next" "next at cli" {
	-re -wrap "func \\(3\\);" {
	    pass $gdb_test_name
	}

	-re "This Is The Event Window" {
	    fail $gdb_test_name
	}
    }

    # Do something just so we know that the CLI is still working.  This
    # also serves to drain the expect buffer if the above test failed.
    gdb_test "print 2 + 2 + 2" " = 6"

    # Now tell the Python code not to check the window is valid before
    # calling rerended.  The result is the Python code will try to draw to
    # the screen.  This should throw a Python exception.
    gdb_test_no_output "python perform_valid_check = False"
    set exception_pattern "\r\nPython Exception\[^\n\r\]+TUI window is invalid\[^\n\r\]+"
    gdb_test_multiple "next" "next at cli, with an exception" {
	-re -wrap "func \\(4\\);${exception_pattern}" {
	    pass $gdb_test_name
	}

	-re "This Is The Event Window" {
	    fail $gdb_test_name
	}
    }

    # Do something just so we know that the CLI is still working.  This
    # also serves to drain the expect buffer if the above test failed.
    gdb_test "print 3 + 3 + 3" " = 9"

    # Set 'update_title' to True.  The Python script will now try to set
    # the window title when an event occurs (instead of trying to redraw
    # the window). As the window is still not displayed this will again
    # through an exception.
    gdb_test_no_output "python update_title = True"
    gdb_test_multiple "next" "next at cli, with an exception for setting the title" {
	-re -wrap "func \\(5\\);${exception_pattern}" {
	    pass $gdb_test_name
	}

	-re "This Is The Event Window" {
	    fail $gdb_test_name
	}
    }

    # We need to perform a restart here as the TUI library we use for
    # testing doesn't seem to handle output in the command window
    # correctly, and gets really upset as we approach the bottom of
    # the screen.
    #
    # Restart GDB, enable tui mode, select the new layout.  Then
    # disable tui and re-enable again.
    if { ![clean_restart_and_setup "second restart"] } {
	unsupported "couldn't restart GDB"
	return
    }

    with_test_prefix "enter tui again" {
	if {![Term::enter_tui]} {
	    unsupported "TUI not supported"
	    return
	}
    }

    Term::command "layout test"
    Term::command "tui disable"
    send_gdb "tui enable\n"
    Term::check_box "check for python window" 0 0 80 16
}

# Run the tests in both cleanup modes.
foreach_with_prefix cleanup_properly { True False } {
    run_test $cleanup_properly
}