#!/usr/bin/env python3
"""A pane whose program exits stays until it is dismissed.

The old behaviour reaped it before the next paint, which meant the last thing
a failing command printed vanished along with the exit status that would have
explained it. Now the pane keeps its contents, says why it is over in its own
backlog and in its frame, and offers the only two verbs left that mean
anything: run it again, or close it.

Buttons are found through the hit list rather than by column, because where
they land is the frame's business and not this test's.
"""

import sys
import tempfile

from harness import Session, check, report

# What a session runs when a layout does not say otherwise: a shell, which
# waits for a line and then exits. (A `cat` in raw mode would not do — raw
# mode is exactly where EOT stops meaning end-of-file.)
SHELL = ["/bin/sh", "-c", 'printf "\\033]2;p\\007"; read x']
LIVES = SHELL
# The same, having painted a known non-default colour into its own content.
GREEN = [
    "/bin/sh",
    "-c",
    'printf "\\033]2;p\\007"; printf "\\033[38;2;0;255;0mBLOCK\\033[0m\\n"; read x',
]
DONE = "q\\n"  # the line those two are waiting for


def cfg(text):
    f = tempfile.NamedTemporaryFile("w", suffix=".kdl", delete=False)
    f.write(text)
    f.close()
    return f.name


def commanded(command):
    """A layout whose single pane was *given* a command.

    That is the distinction the default policy turns on: a pane told to run
    something keeps its corpse, a pane that is just a shell does not. Tests
    about dead panes therefore have to be about commanded ones, or they are
    testing the other half of the rule by accident."""
    return cfg('layout {\n  tab {\n    pane command="%s"\n  }\n}\n' % command)


DIES_CMD = "printf '\\033]2;p\\007'; echo mark-one; exit 3"
# A commanded pane that dies when told, beside a shell that keeps the session
# up: the shape most of the "and then you close it" tests need.
WAITS_CMD = "printf '\\033]2;w\\007'; read x"


def commanded_and_shell(command):
    return cfg('layout {\n  tab {\n    pane command="%s"\n    pane\n  }\n}\n' % command)


def hit(snap, action):
    """(x, y) of the first cell registering an action, or None."""
    for e in snap.hits:
        if e["action"] == action:
            return e["x"], e["y"]
    return None


def output_runs(snap, marker="mark-one"):
    """How many times the command's *output* appears.

    A dead pane now writes the command it ran into its own backlog, and
    `echo mark-one` contains `mark-one` -- so a substring count over the screen
    finds every run twice. The note is the line carrying `[ran:`; every other line
    holding the marker is output. (Counted per line rather than by trimming the
    text: each row still has the pane's frame border on the end of it.)"""
    return sum(1 for l in snap.text if marker in l and "[ran:" not in l)


def test_it_stays_and_says_why():
    with Session(SHELL, cols=60, rows=12, layout=commanded(DIES_CMD)) as s:
        snap = s.until_text("[process exited")
        pane = s.pane()

        check("the pane is still there", len(s.panes()) == 1, str(s.panes()))
        check("and the session with it", s.alive())
        check("what it printed is still on screen", "mark-one" in snap.screen())
        check(
            "the backlog says it exited",
            "[process exited: status 3]" in snap.screen(),
            snap.screen(),
        )
        check("the frame says so too", "exited: status 3" in snap.screen())

        check("json calls it dead", pane["alive"] is False, str(pane))
        check("with the status", pane["exit_code"] == 3, str(pane))
        check("and no signal", pane["exit_signal"] == 0, str(pane))


def test_it_says_what_it_ran():
    """`[re-run]` is one button on a pane whose program is gone. Without the
    command written down, pressing it is a guess -- and in a tab somebody else's
    layout built, the command was never typed here to be scrolled back to."""
    with Session(SHELL, cols=70, rows=12, layout=commanded(DIES_CMD)) as s:
        snap = s.until_text("[process exited")
        screen = snap.screen()
        check("the backlog names the command", "[ran: " in screen, screen)
        check(
            "and it is the command that was given",
            "echo mark-one; exit 3" in screen,
            screen,
        )

        # Above, not below: the exit line is the last word on the run.
        lines = [i for i, l in enumerate(snap.text) if "[ran: " in l]
        exits = [i for i, l in enumerate(snap.text) if "[process exited" in l]
        check(
            "it sits above how it ended",
            lines and exits and lines[0] < exits[0],
            "%s vs %s" % (lines, exits),
        )


def test_a_pane_with_no_command_has_none_to_name():
    """A shell that exited ran what the session runs. `[ran: /bin/sh]` would be
    noise dressed as information."""
    with Session(SHELL, cols=60, rows=10, config=cfg('keep_dead "all"\n')) as s:
        s.settle()
        s.raw(DONE)
        snap = s.until_text("[process exited")
        check(
            "it still says it exited", "[process exited" in snap.screen(), snap.screen()
        )
        check(
            "and says nothing about a command",
            "[ran: " not in snap.screen(),
            snap.screen(),
        )


def test_each_run_says_what_it_was():
    """Re-running keeps the previous run above (D14), so the two notes turn the
    scrollback into a log of what ran rather than a pile of identical epitaphs."""
    with Session(SHELL, cols=70, rows=16, layout=commanded(DIES_CMD)) as s:
        s.until_text("[process exited")
        s.api("rerun", id=0)
        s.settle(120)
        for _ in range(100):
            snap = s.snapshot()
            if snap.screen().count("[ran: ") >= 2:
                break
            s.settle(30)
        check("both runs are named", snap.screen().count("[ran: ") == 2, snap.screen())
        check(
            "and both endings are",
            snap.screen().count("[process exited") == 2,
            snap.screen(),
        )


def test_a_clean_exit_is_not_dressed_up_as_a_failure():
    with Session(SHELL, cols=60, rows=12, layout=commanded("true")) as s:
        snap = s.until_text("[process exited")
        check(
            "no status number for 0", "[process exited]" in snap.screen(), snap.screen()
        )
        check("and the code is reported as 0", s.pane()["exit_code"] == 0)


def test_a_signal_is_named_as_one():
    with Session(SHELL, cols=60, rows=12, layout=commanded("kill -9 $$")) as s:
        snap = s.until_text("[process exited")
        check(
            "the backlog says signal",
            "[process exited: signal 9]" in snap.screen(),
            snap.screen(),
        )
        check("and so does json", s.pane()["exit_signal"] == 9, str(s.pane()))


def test_the_frame_offers_the_two_verbs_that_are_left():
    with Session(SHELL, cols=60, rows=12, layout=commanded(DIES_CMD)) as s:
        snap = s.until_text("[process exited")
        pane = s.pane()

        check("a re-run button", "[re-run]" in snap.screen(), snap.screen())
        check("a close button", "[close]" in snap.screen(), snap.screen())

        rerun = hit(snap, f"rerun:{pane['id']}")
        close = hit(snap, f"close:{pane['id']}")
        check("re-run is clickable", rerun is not None, str(snap.hits))
        check("close is clickable", close is not None, str(snap.hits))
        # Rightmost is the one that must survive a narrow frame.
        check(
            "close sits to the right of re-run", close[0] > rerun[0], f"{rerun} {close}"
        )

        check(
            "the button is drawn where its hit is",
            "[re-run]" in snap.line(rerun[1]),
            snap.line(rerun[1]),
        )


def test_a_live_pane_keeps_its_own_buttons():
    """The dead row replaces the pane's OSC buttons; it must not pre-empt them."""
    argv = [
        "/bin/sh",
        "-c",
        'printf "\\033]5577;1;buttons;go:Go\\033\\\\"; stty raw -echo; cat',
    ]
    with Session(argv, cols=60, rows=12) as s:
        snap = s.until_text("[Go]")
        check("a live pane's own button is drawn", "[Go]" in snap.screen())
        check("and no dead buttons are", "[re-run]" not in snap.screen(), snap.screen())


def test_rerun_runs_it_again_on_top_of_what_it_left():
    # Tall enough that both runs are still on screen rather than in the
    # scrollback: what is being asserted is that the first one was kept.
    with Session(SHELL, cols=60, rows=20, layout=commanded(DIES_CMD)) as s:
        snap = s.until_text("[process exited")
        pane = s.pane()
        x, y = hit(snap, f"rerun:{pane['id']}")
        s.click(x, y)

        snap = s.until(lambda sn: output_runs(sn) == 2)
        check("the command ran again", output_runs(snap) == 2, snap.screen())
        check(
            "the run that ended is still above it",
            "[process exited: status 3]" in snap.screen(),
            snap.screen(),
        )
        check("the pane kept its id", s.pane()["id"] == pane["id"])

        snap = s.until(lambda sn: sn.screen().count("[process exited") == 2)
        check(
            "and dying again says so again",
            snap.screen().count("[process exited: status 3]") == 2,
            snap.screen(),
        )
        check("with the buttons back", "[re-run]" in snap.screen())


def test_rerun_over_the_control_api():
    with Session(SHELL, cols=60, rows=20, layout=commanded(DIES_CMD)) as s:
        s.until_text("[process exited")
        pane = s.pane()
        reply = s.api("rerun", id=pane["id"])
        check("the api runs it again", reply.get("ok") is True, str(reply))
        snap = s.until(lambda sn: output_runs(sn) == 2)
        check("and it really ran", output_runs(snap) == 2, snap.screen())

        reply = s.api("rerun", id=9999)
        check("an unknown pane is refused", reply.get("ok") is False, str(reply))


def test_the_keyboard_can_do_it_too():
    with Session(SHELL, cols=60, rows=20, layout=commanded(DIES_CMD)) as s:
        s.until_text("[process exited")
        s.key("r")
        snap = s.until(lambda sn: output_runs(sn) == 2)
        check("C-a r runs it again", output_runs(snap) == 2, snap.screen())


def test_a_live_pane_is_not_restarted_under_you():
    """ "Run it again" on something still running would mean killing it."""
    with Session(LIVES, cols=60, rows=12) as s:
        s.until_text("p")
        s.key("r")
        s.settle()
        snap = s.snapshot()
        check(
            "it says no rather than doing it",
            "still running" in snap.screen(),
            snap.screen(),
        )
        check("and the pane is untouched", s.pane()["alive"] is True)


def test_closing_it_is_what_takes_it_away():
    # A commanded pane (its corpse is kept) beside a shell (which keeps the
    # session alive once the first one is closed).
    with Session(SHELL, cols=80, rows=16, layout=commanded_and_shell(WAITS_CMD)) as s:
        s.until_text("w")
        s.settle()
        panes = s.panes()
        check("two panes", len(panes) == 2, str(panes))

        # End the commanded one's program and let it die.
        s.api("focus", id=panes[0]["id"])
        s.raw(DONE)
        snap = s.until(lambda sn: "[process exited" in sn.screen())
        check("still two panes", len(s.panes()) == 2, str(s.panes()))

        dead = [p for p in s.panes() if not p["alive"]][0]
        x, y = hit(snap, f"close:{dead['id']}")
        s.click(x, y)
        s.settle()
        check("closing leaves one", len(s.panes()) == 1, str(s.panes()))
        check("and it is the live one", s.panes()[0]["alive"] is True)


def test_a_shell_you_split_off_just_goes_away():
    """The case the policy exists for: split a pane, do something in it, type
    `exit`. A corpse to dismiss there is fussiness, not information — you know
    what happened, you did it."""
    with Session(SHELL, cols=80, rows=16) as s:
        s.until_text("p")
        s.key("\\\\")
        s.settle()
        check("two panes", len(s.panes()) == 2, str(s.panes()))
        s.raw(DONE)
        s.until(lambda sn: len(s.panes()) == 1)
        check("the one you finished with is gone", len(s.panes()) == 1, str(s.panes()))
        check(
            "and left no notice behind",
            "[process exited" not in s.snapshot().screen(),
            s.snapshot().screen(),
        )


def test_a_commanded_pane_keeps_its_corpse():
    """The other half of the same rule, in one place so the pair is legible."""
    with Session(SHELL, cols=80, rows=16, layout=commanded_and_shell(WAITS_CMD)) as s:
        s.until_text("w")
        s.api("focus", id=s.panes()[0]["id"])
        s.raw(DONE)
        snap = s.until(lambda sn: "[process exited" in sn.screen())
        check(
            "a pane that was told to run something stays",
            len(s.panes()) == 2,
            str(s.panes()),
        )
        check("and says so", "[process exited" in snap.screen(), snap.screen())


def test_keep_dead_all_keeps_shells_too():
    conf = cfg('keep_dead "all"\n')
    with Session(SHELL, cols=80, rows=16, config=conf) as s:
        s.until_text("p")
        s.key("\\\\")
        s.settle()
        s.raw(DONE)
        snap = s.until(lambda sn: "[process exited" in sn.screen())
        check("both panes are still there", len(s.panes()) == 2, str(s.panes()))
        check(
            "the shell's corpse stayed",
            "[process exited" in snap.screen(),
            snap.screen(),
        )


def test_keep_dead_none_keeps_nothing():
    conf = cfg('keep_dead "none"\n')
    with Session(
        SHELL, cols=80, rows=16, config=conf, layout=commanded_and_shell(WAITS_CMD)
    ) as s:
        s.until_text("w")
        s.api("focus", id=s.panes()[0]["id"])
        s.raw(DONE)
        s.until(lambda sn: len(s.panes()) == 1)
        check("even a commanded pane is reaped", len(s.panes()) == 1, str(s.panes()))


def test_true_and_false_still_mean_what_they_used_to():
    """`keep_dead true` shipped once. A config that still says it should keep
    working rather than quietly changing behaviour."""
    for word, want in (("true", 2), ("false", 1)):
        conf = cfg("keep_dead %s\n" % word)
        with Session(SHELL, cols=80, rows=16, config=conf) as s:
            s.until_text("p")
            s.key("\\\\")
            s.settle()
            s.raw(DONE)
            s.until(lambda sn: len(s.panes()) == want)
            check(
                f"keep_dead {word} leaves {want} pane(s)",
                len(s.panes()) == want,
                str(s.panes()),
            )


def test_dying_recolours_what_the_pane_left_behind():
    """`dead` is a shader state now, which it could not be while panes were
    reaped before the next paint. Asserted as a change, not as a colour: which
    grey is the config's business."""
    # Doubled on purpose: this lands in a KDL string, whose unescaping turns
    # `\\033` into `\033` for the shell. Written singly the shell gets `033[...`
    # and prints it, which looks like the colour "not working".
    green_cmd = (
        r"printf '\\033]2;p\\007'; "
        r"printf '\\033[38;2;0;255;0mBLOCK\\033[0m\\n'; read x"
    )
    with Session(SHELL, cols=60, rows=12, layout=commanded(green_cmd)) as s:
        snap = s.until_text("BLOCK")
        x, y = snap.find("BLOCK")
        live = snap.style_at(x, y)
        check(
            "a live pane keeps the colour it printed",
            live and live.get("fg") == "#00ff00",
            str(live),
        )

        s.raw(DONE)
        snap = s.until(lambda sn: "[process exited" in sn.screen())
        x, y = snap.find("BLOCK")
        dead = snap.style_at(x, y)
        check("a dead one does not", dead and dead.get("fg") != "#00ff00", str(dead))


def test_a_flattened_tab_still_says_which_pane_is_over():
    """A collapsed header is all a flattened tab draws of a pane, and the
    shader pass does not reach one — so the words have to carry it."""
    with Session(SHELL, cols=100, rows=20, layout=commanded_and_shell(WAITS_CMD)) as s:
        s.until_text("w")
        s.api("focus", id=s.panes()[0]["id"])
        s.raw(DONE)  # the commanded one dies
        s.until(lambda sn: "[process exited" in sn.screen())
        s.api("focus", id=s.panes()[1]["id"])  # focus the live one, so the
        s.settle()  # dead one is what collapses
        s.resize(46, 14)  # no room for two: the tab flattens
        s.settle()

        snap = s.snapshot()
        header = [l for l in snap.text if "· exited" in l]
        check("the header says it exited", header, snap.screen())


def test_the_status_line_names_the_state():
    with Session(SHELL, cols=60, rows=12, layout=commanded(DIES_CMD)) as s:
        snap = s.until_text("[process exited")
        check(
            "the focused dead pane is called exited",
            "exited: status 3" in snap.line(snap.rows - 2),
            snap.line(snap.rows - 2),
        )


for name, fn in sorted(list(globals().items())):
    if name.startswith("test_"):
        fn()
sys.exit(report())