#!/usr/bin/env python3
"""Live check: the status bar lines up with the panes, and its new-tab button
makes a tab.

Both are things you can only see on a real session. The bar is a plugin
rendering into a full-width pane, so nothing in the layout file says where its
first column lands -- and the button is a click surface whose only definition of
"where" is the string it drew.

Usage: status-bar-live.py [path-to-sl0ppij] [path-to-zjstatus.wasm]
"""

import fcntl
import json
import os
import pty
import re
import shutil
import struct
import subprocess
import sys
import tempfile
import termios
import time

HERE = os.path.dirname(os.path.abspath(__file__))
REPO = os.path.abspath(os.path.join(HERE, "../.."))
BIN = os.path.abspath(sys.argv[1] if len(sys.argv) > 1 else f"{REPO}/sl0ppij/target/fastdev/sl0ppij")
WASM = os.path.abspath(
    sys.argv[2]
    if len(sys.argv) > 2
    else f"{REPO}/sl0pstatus/target/wasm32-wasip1/release/zjstatus.wasm"
)
ROWS, COLS = 30, 100
SESSION = f"sl0ptest-bar-{os.getpid()}"

# the horizontal pane gap the bar is supposed to match: `gap` x `gap_aspect`
EXPECTED_MARGIN = 2


def screen_cells(raw):
    """Very small VT: absolute moves, erases, printable runs, and whether each
    cell has a background colour set.

    The background matters. A bar segment usually starts with a padding space
    inside its coloured pill, so "where does the bar begin" is a question about
    painted cells, not about ink -- strip the colour and the answer is off by
    one, which is exactly the size of the thing being measured.
    """
    grid, row, col, i, bg = {}, 0, 0, 0, False
    while i < len(raw):
        ch = raw[i]
        if ch == "\x1b":
            m = re.match(r"\x1b\[([0-9;?]*)([a-zA-Z])", raw[i:])
            if m:
                nums = [int(n) for n in m.group(1).replace("?", "").split(";") if n != ""]
                verb, first = m.group(2), (nums[0] if nums else 0)
                if verb == "m":
                    # 0 = reset, 49 = default background, 40-47/100-107 = set,
                    # 48 = extended (48;5;n or 48;2;r;g;b)
                    if not nums or 0 in nums or 49 in nums:
                        bg = False
                    if any(n == 48 or 40 <= n <= 47 or 100 <= n <= 107 for n in nums):
                        bg = True
                if verb in "Hf":
                    row = (nums[0] - 1) if nums else 0
                    col = (nums[1] - 1) if len(nums) > 1 else 0
                elif verb == "G":
                    col = max(0, first - 1)
                elif verb == "J":
                    if first == 2:
                        grid.clear()
                    else:
                        for c in range(col, COLS):
                            grid.pop((row, c), None)
                        for r in range(row + 1, ROWS):
                            for c in range(COLS):
                                grid.pop((r, c), None)
                elif verb == "K":
                    span = range(col, COLS) if first == 0 else range(0, COLS)
                    for c in span:
                        grid.pop((row, c), None)
                i += m.end()
                continue
            m = re.match(r"\x1b][^\x07\x1b]*(\x07|\x1b\\)", raw[i:])
            if m:
                i += m.end()
                continue
            i += 1
            continue
        if ch == "\r":
            col = 0
        elif ch == "\n":
            row, col = row + 1, 0
        elif ch >= " ":
            grid[(row, col)] = (ch, bg)
            col += 1
        i += 1
    return grid


def screen_rows(raw):
    grid = screen_cells(raw)
    return [
        "".join(grid.get((r, c), (" ", False))[0] for c in range(COLS)) for r in range(ROWS)
    ]


def painted_span(grid, row):
    """(first, last) column of `row` that is drawn on: ink or background."""
    painted = [
        c
        for c in range(COLS)
        if (lambda cell: cell[0] not in (" ", "") or cell[1])(grid.get((row, c), (" ", False)))
    ]
    return (painted[0], painted[-1]) if painted else (None, None)


def repaint(fd):
    """Force a full redraw, discard the intermediate one, read only the final."""
    fcntl.ioctl(fd, termios.TIOCSWINSZ, struct.pack("HHHH", ROWS, COLS - 1, 0, 0))
    time.sleep(0.8)
    try:
        while os.read(fd, 1 << 20):
            pass
    except (BlockingIOError, OSError):
        pass
    fcntl.ioctl(fd, termios.TIOCSWINSZ, struct.pack("HHHH", ROWS, COLS, 0, 0))
    return ""


def read_screen(fd, buffered="", seconds=8, until=None, quiet_for=0.7):
    deadline, last = time.time() + seconds, time.time()
    while time.time() < deadline:
        time.sleep(0.15)
        try:
            chunk = os.read(fd, 1 << 20).decode("utf8", "replace")
        except BlockingIOError:
            chunk = ""
        except OSError:
            break
        if chunk:
            buffered, last = buffered + chunk, time.time()
            continue
        if until and until(screen_rows(buffered)):
            break
        if buffered and time.time() - last >= quiet_for:
            break
    return buffered, screen_rows(buffered)


def bar_row(rows):
    """The bar's CONTENT row: the one with the tab strip on it.

    Not "the last non-blank row" -- framed, that is the bottom border.
    """
    for y in range(len(rows) - 1, -1, -1):
        if "Tab #" in rows[y]:
            return y, rows[y]
    return None, ""


def main():
    global COLS
    for path in (BIN, WASM):
        if not os.path.isfile(path):
            print(f"FAIL: missing {path}")
            return 1

    tmp = tempfile.mkdtemp(prefix="sl0p-bar-")
    config_dir = os.path.join(tmp, "config")
    shutil.copytree(os.path.join(REPO, "config"), config_dir)
    plugins = os.path.join(config_dir, "plugins")
    os.makedirs(plugins, exist_ok=True)
    shutil.copy(WASM, os.path.join(plugins, "zjstatus.wasm"))
    # the shipped config points at ~/.config/sl0ppij; this run is isolated
    for name in ("config.kdl", "layouts/default.kdl", "layouts/default.swap.kdl"):
        path = os.path.join(config_dir, name)
        if not os.path.isfile(path):
            continue
        with open(path) as f:
            text = f.read()
        with open(path, "w") as f:
            f.write(text.replace("~/.config/sl0ppij", config_dir))

    env = dict(os.environ)
    env.update(
        {
            "SL0PPIJ_SOCKET_DIR": os.path.join(tmp, "sock"),
            "SL0PPIJ_CONFIG_FILE": os.path.join(config_dir, "config.kdl"),
            "SL0PPIJ_CONFIG_DIR": config_dir,
            "SL0PPIJ_CACHE_DIR": os.path.join(tmp, "cache"),
            "XDG_CACHE_HOME": os.path.join(tmp, "cache"),
            "TERM": "xterm-256color",
            "SHELL": "/bin/sh",
        }
    )

    pid, fd = pty.fork()
    if pid == 0:
        os.execvpe(BIN, [BIN, "-s", SESSION], env)
    fcntl.ioctl(fd, termios.TIOCSWINSZ, struct.pack("HHHH", ROWS, COLS, 0, 0))
    os.set_blocking(fd, False)

    failures = []
    try:
        _, rows = read_screen(fd, "", seconds=25, until=lambda r: any("Tab #1" in x for x in r))
        raw, rows = read_screen(fd, repaint(fd), seconds=10)
        grid = screen_cells(raw)
        y, bar = bar_row(rows)
        if y is None or "Tab #1" not in bar:
            failures.append("no status bar on screen")
            print("\n".join(f"{i:02d}|{r}" for i, r in enumerate(rows)))
            return failures
        print(f"bar row {y}: {bar.rstrip()!r}")

        # 1. the bar occupies exactly the columns the pane frames do
        bar_span = painted_span(grid, y)
        frame_rows = [i for i, r in enumerate(rows) if r.lstrip().startswith(("╭", "┌"))]
        frame_spans = [
            (r.index(r.lstrip()[0]), len(r.rstrip()) - 1) for i, r in enumerate(rows) if i in frame_rows
        ]
        frame_span = (
            min(s[0] for s in frame_spans),
            max(s[1] for s in frame_spans),
        ) if frame_spans else (None, None)
        print(f"bar spans columns {bar_span}, pane frames span {frame_span}")
        if bar_span != (EXPECTED_MARGIN, COLS - 1 - EXPECTED_MARGIN):
            failures.append(
                f"bar spans {bar_span}, expected "
                f"{(EXPECTED_MARGIN, COLS - 1 - EXPECTED_MARGIN)}"
            )
        if frame_span[0] is not None and bar_span != frame_span:
            failures.append(f"bar spans {bar_span} but the pane frames span {frame_span}")

        # 2. framed: the bar is a box in the pane style, and its borders are
        #    part of it -- a box whose corners do not line up with the panes
        #    above is worse than no box
        if y == 0 or y + 1 >= len(rows):
            failures.append(f"the bar is not framed: content row {y} has no room for borders")
            print("\n".join(f"{i:02d}|{r}" for i, r in enumerate(rows)))
            return failures
        top, bottom = rows[y - 1], rows[y + 1]
        print(f"above: {top.strip()[:12]!r}  below: {bottom.strip()[:12]!r}")
        for label, line, corners in (
            ("top", top, ("╭", "╮")),
            ("bottom", bottom, ("╰", "╯")),
        ):
            span = painted_span(grid, y - 1 if label == "top" else y + 1)
            if span != bar_span:
                failures.append(f"the {label} border spans {span}, the bar spans {bar_span}")
            if line[bar_span[0]] != corners[0] or line[bar_span[1]] != corners[1]:
                failures.append(
                    f"the {label} border does not have rounded corners at its ends: "
                    f"{line[bar_span[0]]!r} {line[bar_span[1]]!r}"
                )

        # 3. the new-tab button makes a tab
        def tabs():
            out = subprocess.run(
                [BIN, "-s", SESSION, "action", "list-tabs", "--json"],
                env=env,
                capture_output=True,
                text=True,
            ).stdout
            try:
                return len(json.loads(out))
            except Exception:
                return out.count('"name"') or len(out.strip().splitlines())

        plus = bar.rfind(" + ")
        if plus < 0:
            failures.append("no new-tab button drawn on the bar")
            return failures
        button_col = plus + 1
        print(f"new-tab button at column {button_col}")
        before = tabs()
        os.write(fd, f"\x1b[<0;{button_col + 1};{y + 1}M".encode())
        os.write(fd, f"\x1b[<0;{button_col + 1};{y + 1}m".encode())
        time.sleep(2)
        after = tabs()
        print(f"tabs: {before} -> {after}")
        if after != before + 1:
            failures.append(f"clicking the new-tab button did not add a tab ({before} -> {after})")

        # 4. and a click just left of the tab strip must not: the button is a
        #    button, not "anywhere on the right half of the bar"
        before = tabs()
        os.write(fd, f"\x1b[<0;{max(1, plus - 2)};{y + 1}M".encode())
        os.write(fd, f"\x1b[<0;{max(1, plus - 2)};{y + 1}m".encode())
        time.sleep(1.5)
        if tabs() != before:
            failures.append("a click beside the button also made a tab")

        # 5. a click on the box itself must not either: the frame is chrome
        before = tabs()
        os.write(fd, f"\x1b[<0;{button_col + 1};{y}M".encode())
        os.write(fd, f"\x1b[<0;{button_col + 1};{y}m".encode())
        time.sleep(1.5)
        if tabs() != before:
            failures.append("a click on the bar's top border made a tab")

        # 6. collapsed ("mobile"): below responsive_min_cols the tab layout
        #    swaps to the stacked one, whose template gives the bar a single
        #    row -- and the plugin must then draw a line, not a broken box
        narrow = 70
        fcntl.ioctl(fd, termios.TIOCSWINSZ, struct.pack("HHHH", ROWS, narrow, 0, 0))
        time.sleep(2.5)
        wide, COLS = COLS, narrow
        try:
            raw, rows = read_screen(fd, "", seconds=10)
            grid = screen_cells(raw)
            y, bar = bar_row(rows)
            if y is None:
                failures.append("no status bar after collapsing to the mobile layout")
                return failures
            above = rows[y - 1] if y > 0 else ""
            below = rows[y + 1] if y + 1 < len(rows) else ""
            print(f"collapsed: bar row {y}, above {above.strip()[:14]!r}")
            if any(c in above or c in below for c in "╭╮╰╯"):
                failures.append("the collapsed bar still draws a box")
            span = painted_span(grid, y)
            if span != (EXPECTED_MARGIN, narrow - 1 - EXPECTED_MARGIN):
                failures.append(f"collapsed bar spans {span}, expected margins only")
            plus = bar.rfind(" + ")
            if plus < 0:
                failures.append("no new-tab button on the collapsed bar")
            else:
                before = tabs()
                os.write(fd, f"\x1b[<0;{plus + 2};{y + 1}M".encode())
                os.write(fd, f"\x1b[<0;{plus + 2};{y + 1}m".encode())
                time.sleep(2)
                after = tabs()
                print(f"collapsed tabs: {before} -> {after}")
                if after != before + 1:
                    failures.append(
                        f"the collapsed bar's button did not make a tab ({before} -> {after})"
                    )
        finally:
            COLS = wide
        return failures
    finally:
        subprocess.run([BIN, "kill-session", SESSION], env=env, capture_output=True)
        # `kill-session NAME`, not `-s NAME kill-session`: the latter parses but
        # leaves the session running. Delete too: killed sessions linger in
        # `list-sessions` as resurrectable.
        subprocess.run([BIN, "delete-session", SESSION], env=env, capture_output=True)
        try:
            os.close(fd)
        except OSError:
            pass
        os.waitpid(pid, os.WNOHANG)
        time.sleep(1)
        ps = subprocess.run(["ps", "-eo", "pid,comm,args"], capture_output=True, text=True).stdout
        for line in ps.splitlines():
            fields = line.split(None, 2)
            if len(fields) == 3 and fields[1] == os.path.basename(BIN) and tmp in fields[2]:
                try:
                    os.kill(int(fields[0]), 15)
                except (ProcessLookupError, ValueError, PermissionError):
                    pass
        shutil.rmtree(tmp, ignore_errors=True)


if __name__ == "__main__":
    problems = main()
    if problems == 1:
        sys.exit(1)
    for p in problems:
        print(f"FAIL: {p}")
    if not problems:
        print("ok: the bar lines up with the panes and its + makes a tab")
    sys.exit(1 if problems else 0)