"""Tests for Bot.long_reply() paste overflow behaviour."""

import asyncio
import types

from derp.bot import Bot
from derp.irc import Message
from derp.plugin import PluginRegistry

# -- Helpers -----------------------------------------------------------------

def _make_bot(*, paste_threshold: int = 4, flaskpaste_mod=None) -> Bot:
    """Build a Bot with minimal config and a captured send log."""
    config = {
        "server": {
            "host": "localhost", "port": 6667, "tls": False,
            "nick": "testbot", "user": "testbot", "realname": "test",
        },
        "bot": {
            "prefix": "!",
            "channels": ["#test"],
            "plugins_dir": "plugins",
            "rate_limit": 100.0,
            "rate_burst": 100,
            "paste_threshold": paste_threshold,
            "admins": [],
        },
    }
    registry = PluginRegistry()
    if flaskpaste_mod is not None:
        registry._modules["flaskpaste"] = flaskpaste_mod
    bot = Bot("test", config, registry)
    bot._sent: list[tuple[str, str]] = []  # type: ignore[attr-defined]

    async def _capturing_send(target: str, text: str) -> None:
        bot._sent.append((target, text))

    bot.send = _capturing_send  # type: ignore[assignment]
    return bot


def _msg(text: str = "", target: str = "#test", nick: str = "alice") -> Message:
    """Create a channel PRIVMSG."""
    return Message(
        raw="", prefix=f"{nick}!~{nick}@host", nick=nick,
        command="PRIVMSG", params=[target, text], tags={},
    )


def _pm(text: str = "", nick: str = "alice") -> Message:
    """Create a private PRIVMSG (target = bot nick)."""
    return Message(
        raw="", prefix=f"{nick}!~{nick}@host", nick=nick,
        command="PRIVMSG", params=["testbot", text], tags={},
    )


def _make_fp_mod(*, paste_url: str | None = "https://paste.example/abc"):
    """Build a fake flaskpaste module with create_paste()."""
    mod = types.ModuleType("flaskpaste")
    mod.create_paste = lambda bot, content: paste_url  # type: ignore[attr-defined]
    return mod


# -- Tests -------------------------------------------------------------------

class TestShortReply:
    def test_sends_all(self):
        """Lines <= threshold are sent individually, no paste."""
        bot = _make_bot(paste_threshold=4)
        msg = _msg()
        lines = ["line 1", "line 2", "line 3"]
        asyncio.run(bot.long_reply(msg, lines))
        assert len(bot._sent) == 3
        assert bot._sent[0] == ("#test", "line 1")
        assert bot._sent[1] == ("#test", "line 2")
        assert bot._sent[2] == ("#test", "line 3")


class TestLongReply:
    def test_creates_paste(self):
        """Lines > threshold creates paste, sends preview + URL."""
        fp = _make_fp_mod(paste_url="https://paste.example/xyz")
        bot = _make_bot(paste_threshold=3, flaskpaste_mod=fp)
        msg = _msg()
        lines = ["line 1", "line 2", "line 3", "line 4", "line 5"]
        asyncio.run(bot.long_reply(msg, lines, label="results"))
        # preview_count = min(2, threshold-1) = min(2, 2) = 2
        assert len(bot._sent) == 3
        assert bot._sent[0] == ("#test", "line 1")
        assert bot._sent[1] == ("#test", "line 2")
        assert "3 more lines" in bot._sent[2][1]
        assert "(results)" in bot._sent[2][1]
        assert "https://paste.example/xyz" in bot._sent[2][1]

    def test_fallback_no_flaskpaste(self):
        """No flaskpaste module loaded -- falls back to sending all lines."""
        bot = _make_bot(paste_threshold=2)
        msg = _msg()
        lines = ["a", "b", "c", "d"]
        asyncio.run(bot.long_reply(msg, lines))
        assert len(bot._sent) == 4
        assert [t for _, t in bot._sent] == ["a", "b", "c", "d"]

    def test_fallback_paste_fails(self):
        """create_paste returns None -- falls back to sending all lines."""
        fp = _make_fp_mod(paste_url=None)
        bot = _make_bot(paste_threshold=2, flaskpaste_mod=fp)
        msg = _msg()
        lines = ["a", "b", "c"]
        asyncio.run(bot.long_reply(msg, lines))
        assert len(bot._sent) == 3
        assert [t for _, t in bot._sent] == ["a", "b", "c"]

    def test_label_in_overflow_message(self):
        """Label appears in the overflow message."""
        fp = _make_fp_mod()
        bot = _make_bot(paste_threshold=2, flaskpaste_mod=fp)
        msg = _msg()
        lines = ["a", "b", "c"]
        asyncio.run(bot.long_reply(msg, lines, label="history"))
        overflow = bot._sent[-1][1]
        assert "(history)" in overflow

    def test_no_label(self):
        """Overflow message omits label suffix when label is empty."""
        fp = _make_fp_mod()
        bot = _make_bot(paste_threshold=2, flaskpaste_mod=fp)
        msg = _msg()
        lines = ["a", "b", "c"]
        asyncio.run(bot.long_reply(msg, lines))
        overflow = bot._sent[-1][1]
        assert "more lines:" in overflow
        assert "()" not in overflow


class TestThreshold:
    def test_configurable(self):
        """Custom threshold from config controls overflow point."""
        fp = _make_fp_mod()
        bot = _make_bot(paste_threshold=10, flaskpaste_mod=fp)
        msg = _msg()

        # 10 lines == threshold -> no paste
        lines_at = [f"line {i}" for i in range(10)]
        asyncio.run(bot.long_reply(msg, lines_at))
        assert len(bot._sent) == 10

    def test_over_threshold_pastes(self):
        """Lines exceeding threshold triggers paste."""
        fp = _make_fp_mod()
        bot = _make_bot(paste_threshold=10, flaskpaste_mod=fp)
        msg = _msg()
        lines_over = [f"line {i}" for i in range(11)]
        asyncio.run(bot.long_reply(msg, lines_over))
        assert len(bot._sent) == 3  # 2 preview + overflow msg


class TestEdgeCases:
    def test_empty_lines_noop(self):
        """Empty list produces no output."""
        bot = _make_bot()
        msg = _msg()
        asyncio.run(bot.long_reply(msg, []))
        assert bot._sent == []

    def test_pm_uses_nick(self):
        """Private messages use nick as target."""
        bot = _make_bot(paste_threshold=4)
        msg = _pm()
        lines = ["x", "y"]
        asyncio.run(bot.long_reply(msg, lines))
        assert len(bot._sent) == 2
        assert bot._sent[0] == ("alice", "x")
        assert bot._sent[1] == ("alice", "y")