Shot chart photo in the post-shot message

flake.nix

@@ -19,6 +19,7 @@
             build-system = [ pkgs.python3Packages.hatchling ];
             dependencies = with pkgs.python3Packages; [
               aiohttp
+              matplotlib
               python-telegram-bot
               # discord.py is optional at runtime; add it when using the discord messenger
             ] ++ pkgs.lib.optional (pkgs.python3Packages ? discordpy) pkgs.python3Packages.discordpy;

pyproject.toml

@@ -22,7 +22,8 @@ dependencies = ["aiohttp>=3.9"]
 telegram = ["python-telegram-bot>=21,<23"]
 discord = ["discord.py>=2.3"]
 matrix = ["matrix-nio>=0.24"]
-all = ["matebot[telegram,discord,matrix]"]
+plots = ["matplotlib>=3.8"]
+all = ["matebot[telegram,discord,matrix,plots]"]
 dev = ["pytest>=8", "pytest-asyncio>=0.23", "ruff>=0.4"]
 
 [project.urls]

src/matebot/cli.py

@@ -214,12 +214,25 @@ async def on_utility(profile):
                             "volume_g": shot.entry.volume_g,
                         },
                     )
+                    photo = None
+                    if config.plots_enabled:
+                        try:
+                            from .plot import render_shot_png
+                            from .slog import parse_slog
+
+                            parsed = parse_slog(await client.fetch_slog(shot.entry.id))
+                            photo = render_shot_png(
+                                parsed, title=f"Shot #{shot.entry.id} — {parsed.profile_name}"
+                            )
+                        except Exception as exc:  # noqa: BLE001 - photo is a nice-to-have
+                            log.info("shot plot skipped: %s", exc)
                     try:
                         await convo.start_shot(
                             shot.entry.id,
                             shot.profile_label or shot.entry.profile_name,
                             shot.duration_ms,
                             shot.entry.volume_g,
+                            photo=photo,
                         )
                     except Exception:  # noqa: BLE001 - keep watching even if messaging fails
                         log.exception("questionnaire start failed (state kept for resume)")

src/matebot/config.py

@@ -29,6 +29,7 @@
     "hints_enabled": "MATEBOT_HINTS",
     "digest_enabled": "MATEBOT_DIGEST",
     "clean_every": "MATEBOT_CLEAN_EVERY",
+    "plots_enabled": "MATEBOT_PLOTS",
 }
 
 
@@ -55,6 +56,7 @@ class Config:
     hints_enabled: bool = True  # dial-in suggestions after sour/bitter/low-rated shots
     digest_enabled: bool = True  # weekly summary on Sunday evening
     clean_every: int = 40  # backflush reminder every N espresso shots; 0 = off
+    plots_enabled: bool = True  # send the shot chart as a photo (needs matplotlib)
 
     @classmethod
     def load(cls, path: str | Path | None = None) -> Config:
@@ -74,7 +76,7 @@ def load(cls, path: str | Path | None = None) -> Config:
                 value = float(value)
             elif f.name == "clean_every":
                 value = int(value)
-            elif f.name in ("sync_enabled", "hints_enabled", "digest_enabled"):
+            elif f.name in ("sync_enabled", "hints_enabled", "digest_enabled", "plots_enabled"):
                 value = str(value).lower() in ("1", "true", "yes", "on")
             kwargs[f.name] = value
         config = cls(**kwargs)

src/matebot/conversation.py

@@ -112,7 +112,8 @@ def __init__(
     # ------------------------------------------------------------- shots
 
     async def start_shot(
-        self, shot_id: int, profile: str, duration_ms: int, volume_g: float
+        self, shot_id: int, profile: str, duration_ms: int, volume_g: float,
+        photo: bytes | None = None,
     ) -> None:
         if self.pending is not None:
             await self._finish(superseded_by=shot_id)
@@ -124,7 +125,10 @@ async def start_shot(
             + (f" · {volume_g:.1f} g in the cup" if volume_g else "")
             + "\n\nLet's log it before you forget:"
         )
-        await self.messenger.send(summary)
+        if photo:
+            await self.messenger.send_photo(photo, summary)
+        else:
+            await self.messenger.send(summary)
         await self._prompt()
 
     async def resume_if_pending(self) -> None:

src/matebot/messengers/base.py

@@ -48,6 +48,11 @@ async def send(self, text: str, options: list[Option] | None = None) -> str:
     async def edit(self, ref: str, text: str, options: list[Option] | None = None) -> None:
         """Replace a previously sent message's text/options (best effort)."""
 
+    async def send_photo(self, image: bytes, caption: str) -> str:
+        """Send an image with caption; backends without photo support fall
+        back to the caption text."""
+        return await self.send(caption)
+
     @abstractmethod
     def events(self) -> AsyncIterator[Event]:
         """User interactions, in order. Runs until stop()."""

src/matebot/messengers/discord.py

@@ -66,6 +66,15 @@ async def send(self, text: str, options: list[Option] | None = None) -> str:
         msg = await channel.send(text, view=self._view(options))
         return str(msg.id)
 
+    async def send_photo(self, image: bytes, caption: str) -> str:
+        import io as _io
+
+        import discord
+
+        channel = self.client.get_channel(self.channel_id)
+        msg = await channel.send(caption, file=discord.File(_io.BytesIO(image), "shot.png"))
+        return str(msg.id)
+
     async def edit(self, ref: str, text: str, options: list[Option] | None = None) -> None:
         try:
             channel = self.client.get_channel(self.channel_id)

src/matebot/messengers/telegram.py

@@ -92,6 +92,18 @@ async def send(self, text: str, options: list[Option] | None = None) -> str:
                 await asyncio.sleep(2 * (attempt + 1))
         raise last_exc
 
+    async def send_photo(self, image: bytes, caption: str) -> str:
+        last_exc = None
+        for attempt in range(5):
+            try:
+                msg = await self.app.bot.send_photo(self.chat_id, photo=image, caption=caption)
+                return str(msg.message_id)
+            except Exception as exc:  # noqa: BLE001
+                last_exc = exc
+                log.warning("photo send attempt %d failed: %s", attempt + 1, exc)
+                await asyncio.sleep(2 * (attempt + 1))
+        raise last_exc
+
     async def edit(self, ref: str, text: str, options: list[Option] | None = None) -> None:
         try:
             await self.app.bot.edit_message_text(

src/matebot/plot.py

@@ -0,0 +1,91 @@
+"""Render a shot as a PNG chart (sent as the post-shot photo).
+
+Same visual language as the journal and the GaggiMate web UI: temperature on
+the left axis, pressure/flow on the right, weight on its own scale, dashed
+targets, phase markers. matplotlib is an optional dependency (``[plots]``
+extra) — callers fall back to a text summary when it is missing.
+"""
+
+from __future__ import annotations
+
+import io
+
+from .slog import Shot
+
+COLORS = {
+    "temp": "#e64a19",
+    "press": "#1e88e5",
+    "flow": "#43a047",
+    "puck": "#1b5e20",
+    "weight": "#8e24aa",
+}
+
+
+def render_shot_png(shot: Shot, *, title: str | None = None) -> bytes:
+    import matplotlib
+
+    matplotlib.use("Agg")
+    import matplotlib.pyplot as plt
+
+    t = shot.times_s
+    s = shot.series
+    have = lambda k: k in s and any(s[k])  # noqa: E731
+
+    fig, ax_temp = plt.subplots(figsize=(8, 4.5), dpi=110)
+    ax_bar = ax_temp.twinx()
+
+    if have("ct"):
+        ax_temp.plot(t, s["ct"], color=COLORS["temp"], lw=1.8, label="Temp")
+    if have("tt"):
+        ax_temp.plot(t, s["tt"], color=COLORS["temp"], lw=1.1, ls="--", alpha=0.7)
+    if have("cp"):
+        ax_bar.plot(t, s["cp"], color=COLORS["press"], lw=2.0, label="Pressure")
+    if have("tp"):
+        ax_bar.plot(t, s["tp"], color=COLORS["press"], lw=1.1, ls="--", alpha=0.7)
+    if have("fl"):
+        ax_bar.plot(t, s["fl"], color=COLORS["flow"], lw=1.5, label="Pump flow")
+    if have("pf"):
+        ax_bar.plot(t, s["pf"], color=COLORS["puck"], lw=1.5, label="Puck flow")
+
+    weight = s.get("v") if have("v") else s.get("ev") if have("ev") else None
+    if weight:
+        ax_g = ax_temp.twinx()
+        ax_g.spines.right.set_position(("axes", 1.12))
+        ax_g.plot(t, weight, color=COLORS["weight"], lw=1.8, label="Weight")
+        ax_g.set_ylabel("g", color=COLORS["weight"])
+        ax_g.set_ylim(bottom=0)
+        ax_g.tick_params(axis="y", colors=COLORS["weight"], labelsize=8)
+
+    for phase in shot.phases:
+        px = phase.sample_index * shot.sample_interval_ms / 1000
+        if 0.3 < px < (t[-1] if t else 0) - 0.3:
+            ax_temp.axvline(px, color="#999", lw=0.7, ls=":", alpha=0.7)
+            ax_temp.annotate(
+                phase.name[:18], (px, 1.0), xycoords=("data", "axes fraction"),
+                rotation=90, va="top", ha="right", fontsize=6.5, color="#777",
+            )
+
+    ax_temp.set_xlabel("s", fontsize=8)
+    ax_temp.set_ylabel("°C", color=COLORS["temp"], fontsize=9)
+    ax_temp.tick_params(labelsize=8)
+    ax_temp.tick_params(axis="y", colors=COLORS["temp"])
+    ax_bar.set_ylabel("bar · g/s", color=COLORS["press"], fontsize=9)
+    ax_bar.tick_params(axis="y", colors=COLORS["press"], labelsize=8)
+    ax_bar.set_ylim(bottom=0)
+    ax_temp.grid(True, axis="y", lw=0.3, alpha=0.4)
+    if title:
+        ax_temp.set_title(title, fontsize=10)
+
+    handles, labels = [], []
+    for ax in fig.axes:
+        h, lab = ax.get_legend_handles_labels()
+        handles += h
+        labels += lab
+    fig.legend(handles, labels, loc="lower center", ncol=len(labels),
+               bbox_to_anchor=(0.5, 0.0), fontsize=7.5, frameon=False)
+
+    fig.tight_layout(rect=(0, 0.08, 1, 1))
+    buf = io.BytesIO()
+    fig.savefig(buf, format="png")
+    plt.close(fig)
+    return buf.getvalue()

tests/test_plot.py

@@ -0,0 +1,17 @@
+import pathlib
+
+import pytest
+
+pytest.importorskip("matplotlib")
+
+from matebot.plot import render_shot_png  # noqa: E402
+from matebot.slog import parse_slog  # noqa: E402
+
+GOLDEN = pathlib.Path(__file__).parent / "fixtures" / "000004.slog"
+
+
+def test_render_png_from_golden_shot():
+    shot = parse_slog(GOLDEN.read_bytes())
+    png = render_shot_png(shot, title="Shot #4 — Adaptive v2")
+    assert png[:8] == b"\x89PNG\r\n\x1a\n"
+    assert len(png) > 20_000  # an actual chart, not an empty canvas