app.py

"""Srijika — text-to-font studio for Indic scripts (public demo).

Thin client for the private Srijika API. No model code or weights here:
every render arrives as a PNG from the server. The demo key lives in a
Space Secret (SRIJIKA_DEMO_KEY) and is never exposed to visitors.
"""

import io
import os
import time

import gradio as gr
import requests

API = os.environ.get("SRIJIKA_API_URL",
                     "https://loopdesk-ai--srijika-api-api.modal.run")
KEY = os.environ.get("SRIJIKA_DEMO_KEY", "")
HDRS = {"Authorization": f"Bearer {KEY}"}

SCRIPTS = ["devanagari", "tamil", "bengali", "telugu", "kannada",
           "malayalam", "gujarati", "gurmukhi", "odia"]

EXAMPLES = [
    ["a heavy rounded poster font", "devanagari"],
    ["thin elegant headline serif", "devanagari"],
    ["playful comic lettering for kids", "bengali"],
    ["clean geometric UI font", "tamil"],
    ["warm rounded friendly font", "kannada"],
    ["sharp modern tech branding", "telugu"],
    ["traditional elegant bookish serif", "malayalam"],
    ["bold cinematic display font", "gujarati"],
    ["clean geometric sans", "gurmukhi"],
    ["warm rounded friendly font", "odia"],
    ["brush calligraphy with dramatic strokes", "devanagari"],
]

CSS = """
.gradio-container {max-width: 1080px !important; margin: 0 auto;}
#hero {text-align:center; padding: 26px 10px 6px;}
#hero h1 {font-size: 2.5em; margin: 0;
  background: linear-gradient(90deg,#f59e0b,#ef4444,#a855f7);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent;}
#hero p {color:#6b7280; margin-top:6px; font-size:1.05em;}
.badge {display:inline-block; background:#111827; color:#e5e7eb;
  border-radius:999px; padding:3px 12px; margin:2px; font-size:.8em;}
#donorcard {border:1px solid #e5e7eb; border-radius:14px; padding:14px;
  background:linear-gradient(180deg,#fffbeb,#ffffff);}
#status {font-size:.95em;}
footer {display:none !important;}
"""

HERO = """
<div id="hero">
  <h1>Srijika · सृजिका</h1>
  <p>Describe a font in plain words &rarr; a diffusion model draws it,
     glyph by glyph, for Devanagari, Tamil, Bengali, Telugu, Kannada,
     Malayalam, Gujarati, Gurmukhi &amp; Odia.</p>
  <span class="badge">text &rarr; font</span>
  <span class="badge">glyph diffusion</span>
  <span class="badge">FontCLIP retrieval</span>
  <span class="badge">parametric axes</span>
  <span class="badge">draft = 30 glyphs &middot; ~2 min</span>
</div>
"""

ABOUT = """
**How it works** — Your description is embedded by
[Lipika-FontCLIP](https://huggingface.co/loopdesk-ai/lipika-fontclip) and
matched against 1,700+ Indic font faces. The best match seeds a private
glyph-diffusion model (Srijika) that redraws the alphabet in that style on
a GPU. Drafts render 30 glyphs so you can iterate quickly; the full model
draws complete Unicode coverage with conjuncts.

**Parametric axes** — after generation, weight / counter / em-fill are
geometric transforms applied server-side, so one generation yields a family.

*Public demo: draft quality, rate-limited, shared queue. Fonts are derived
from OFL-licensed donors.*
"""


def _get(path, **params):
    r = requests.get(f"{API}{path}", headers=HDRS, params=params, timeout=120)
    r.raise_for_status()
    return r


def _png(resp):
    return resp.content if resp.headers.get(
        "content-type", "").startswith("image/") else None


def api_ok():
    try:
        return requests.get(f"{API}/v1/health", timeout=10).ok and bool(KEY)
    except Exception:
        return False


# ---------------------------------------------------------------- search
def do_search(q, script):
    if not q.strip():
        return "Type a description first.", gr.update(visible=False)
    try:
        d = _get("/v1/search", q=q, script=script or "", k=6).json()
    except requests.HTTPError as e:
        return f"Search failed: {e.response.text[:200]}", gr.update(visible=False)
    rows, gallery = [], []
    for r in d["results"]:
        rows.append(f"**{r['family']}**  ·  score {r['score']:.3f}")
        if r.get("file"):
            try:
                png = _png(_get("/v1/donor-preview",
                                file=r["file"], script=script or "devanagari"))
                if png:
                    gallery.append((io.BytesIO(png).getvalue(), r["family"]))
            except Exception:
                pass
    import tempfile
    paths = []
    for data, label in gallery:
        f = tempfile.NamedTemporaryFile(suffix=".png", delete=False)
        f.write(data)
        f.close()
        paths.append((f.name, label))
    md = (f"**{d.get('n_candidates', len(d['results']))} candidate faces "
          f"searched** — top matches:\n\n" + "\n\n".join(rows))
    return md, gr.update(value=paths, visible=bool(paths))


# -------------------------------------------------------------- generate
def do_generate(text, script, progress=gr.Progress()):
    empty = gr.update(visible=False)
    if not text.strip():
        yield "Type a description first.", None, None, empty, gr.update(visible=False)
        return
    progress(0.02, desc="Finding the closest real font…")
    try:
        r = requests.post(f"{API}/v1/generate", headers=HDRS,
                          data={"text": text, "script": script}, timeout=300)
        r.raise_for_status()
        d = r.json()
    except requests.HTTPError as e:
        code = e.response.status_code
        msg = ("Rate limit reached — the shared demo allows a few "
               "generations per hour. Try again later."
               if code == 429 else f"Generate failed: {e.response.text[:300]}")
        yield msg, None, None, empty, gr.update(visible=False)
        return
    job, donor = d["job_id"], d["donor"]
    donor_md = (f"### 🎯 Donor matched: **{donor['family']}**\n"
                f"score {donor['score']:.3f} · "
                f"{d['n_candidates']} faces searched · "
                f"template `{d['params']['template']}`")
    yield (f"⏳ Drawing glyphs on GPU (draft, ~2 min)… job `{job}`",
           None, None, gr.update(value=donor_md, visible=True),
           gr.update(visible=False))
    t0 = time.time()
    while time.time() - t0 < 420:
        progress(min(.05 + (time.time() - t0) / 140 * .9, .95),
                 desc="Diffusing glyphs…")
        time.sleep(6)
        try:
            s = _get(f"/v1/jobs/{job}").json()
        except Exception:
            continue
        if s.get("status") == "done":
            c = s["critic"]
            cl = c.get("cluster") or {}
            n_g = s.get("stats", {}).get("replaced", "?")
            png = _png(_get(f"/v1/jobs/{job}/preview"))
            ttf = _get(f"/v1/jobs/{job}/font").content
            import tempfile
            pf = tempfile.NamedTemporaryFile(suffix=".png", delete=False)
            pf.write(png or b"")
            pf.close()
            tf = tempfile.NamedTemporaryFile(
                suffix=".ttf", delete=False,
                prefix=s["params"]["family"].replace(" ", "") + "-")
            tf.write(ttf)
            tf.close()
            acc = cl.get("acc")
            stat = (f"✅ **Done in {time.time()-t0:.0f}s** · "
                    f"{n_g} glyphs drawn · "
                    f"legible {c['legible_frac']:.2f}"
                    + (f" · cluster acc {acc:.2f}" if acc is not None else "")
                    + f"\n\njob `{job}`")
            yield (stat, pf.name, tf.name,
                   gr.update(value=donor_md, visible=True),
                   gr.update(visible=True))
            return
        if s.get("status") == "failed":
            yield (f"❌ Job failed: {s.get('error','?')[:300]}",
                   None, None, empty, gr.update(visible=False))
            return
    yield ("⌛ Still running — press *Check again* in a minute.",
           None, None, gr.update(value=donor_md, visible=True),
           gr.update(visible=False))


def apply_axes(state_job, weight, counter, emfill):
    if not state_job:
        return None, None, "Generate a font first."
    try:
        png = _png(_get(f"/v1/jobs/{state_job}/preview",
                        weight=weight, counter=counter, emfill=emfill))
        ttf = _get(f"/v1/jobs/{state_job}/font",
                   weight=weight, counter=counter, emfill=emfill)
    except requests.HTTPError as e:
        return None, None, f"Axis render failed: {e.response.text[:200]}"
    import tempfile
    pf = tempfile.NamedTemporaryFile(suffix=".png", delete=False)
    pf.write(png or b"")
    pf.close()
    disp = ttf.headers.get("content-disposition", "")
    name = disp.split("filename=")[-1].strip('"') or "srijika.ttf"
    tf = tempfile.NamedTemporaryFile(suffix=".ttf", delete=False,
                                     prefix=name.rsplit(".", 1)[0] + "-")
    tf.write(ttf.content)
    tf.close()
    rep = ttf.headers.get("x-srijika-axes", "")
    return pf.name, tf.name, f"Axes applied · `{rep}`" if rep else "Axes applied."


# --------------------------------------------------------------- presets
def load_presets():
    try:
        d = _get("/v1/presets").json()
    except Exception as e:
        return gr.update(choices=[], value=None), f"Could not load presets: {e}"
    ids = [p["id"] for p in d["presets"]]
    return (gr.update(choices=ids, value=ids[0] if ids else None),
            f"{d['count']} preset styles available.")


def show_preset(pid, weight, counter, emfill):
    if not pid:
        return None, None, "Pick a preset."
    try:
        png = _png(_get(f"/v1/presets/{pid}/preview",
                        weight=weight, counter=counter, emfill=emfill))
        ttf = _get(f"/v1/presets/{pid}/font",
                   weight=weight, counter=counter, emfill=emfill).content
    except requests.HTTPError as e:
        return None, None, f"Preset failed: {e.response.text[:200]}"
    import tempfile
    pf = tempfile.NamedTemporaryFile(suffix=".png", delete=False)
    pf.write(png or b"")
    pf.close()
    tf = tempfile.NamedTemporaryFile(suffix=".ttf", delete=False,
                                     prefix=pid + "-")
    tf.write(ttf)
    tf.close()
    return pf.name, tf.name, f"**{pid}** ready."


# ------------------------------------------------------------------- UI
with gr.Blocks(css=CSS, title="Srijika — text to Indic font",
               theme=gr.themes.Soft(primary_hue="amber")) as demo:
    gr.HTML(HERO)
    if not api_ok():
        gr.Markdown("> ⚠️ **Demo backend unreachable or key missing.** "
                    "The API may be waking up — reload in a minute.")

    with gr.Tab("✨ Text → Font"):
        with gr.Row():
            txt = gr.Textbox(label="Describe your font",
                             placeholder="e.g. a heavy rounded poster font "
                                         "with warm friendly curves",
                             scale=4)
            scr = gr.Dropdown(SCRIPTS, value="devanagari",
                              label="Script", scale=1)
        gen_btn = gr.Button("Generate draft font", variant="primary")
        gr.Examples(EXAMPLES, inputs=[txt, scr], label="Try one of these")
        donor_card = gr.Markdown(visible=False, elem_id="donorcard")
        status = gr.Markdown(elem_id="status")
        with gr.Row():
            preview = gr.Image(label="Specimen", type="filepath",
                               interactive=False)
        ttf_out = gr.File(label="Download TTF")
        with gr.Group(visible=False) as axes_grp:
            gr.Markdown("#### 🎛 Parametric axes — restyle without re-generating")
            with gr.Row():
                w = gr.Slider(-40, 80, 0, step=5, label="Weight")
                c = gr.Slider(0.8, 1.2, 1.0, step=0.05, label="Counter")
                e = gr.Slider(0.95, 1.06, 1.0, step=0.01, label="Em-fill")
            ax_btn = gr.Button("Apply axes")
        job_state = gr.State("")

        gen_btn.click(
            do_generate, [txt, scr],
            [status, preview, ttf_out, donor_card, axes_grp])

        def grab_job(stat_md):
            import re
            m = re.findall(r"job `([^`]+)`", stat_md or "")
            return m[-1] if m else gr.update()

        status.change(grab_job, status, job_state)
        ax_btn.click(apply_axes, [job_state, w, c, e],
                     [preview, ttf_out, status])

    with gr.Tab("🎨 Preset gallery"):
        gr.Markdown("Pre-generated Srijika families — instant download, "
                    "same parametric axes.")
        with gr.Row():
            pre_dd = gr.Dropdown([], label="Preset", scale=3)
            pre_btn = gr.Button("Load presets", scale=1)
        pre_msg = gr.Markdown()
        with gr.Row():
            pw = gr.Slider(-40, 80, 0, step=5, label="Weight")
            pc = gr.Slider(0.8, 1.2, 1.0, step=0.05, label="Counter")
            pe = gr.Slider(0.95, 1.06, 1.0, step=0.01, label="Em-fill")
        pre_show = gr.Button("Render specimen", variant="primary")
        pre_img = gr.Image(label="Specimen", type="filepath", interactive=False)
        pre_file = gr.File(label="Download TTF")
        pre_btn.click(load_presets, None, [pre_dd, pre_msg])
        pre_show.click(show_preset, [pre_dd, pw, pc, pe],
                       [pre_img, pre_file, pre_msg])

    with gr.Tab("🔎 Donor search"):
        gr.Markdown("Peek at the retrieval layer: which **real** Indic fonts "
                    "best match a description (Lipika-FontCLIP fc-v7: 48 style "
                    "attributes incl. measured stroke contrast).")
        with gr.Row():
            sq = gr.Textbox(label="Description",
                            placeholder="thin elegant headline serif", scale=4)
            ss = gr.Dropdown([""] + SCRIPTS, value="", label="Script filter",
                             scale=1)
        s_btn = gr.Button("Search corpus", variant="primary")
        s_md = gr.Markdown()
        s_gal = gr.Gallery(label="Top donor faces", columns=3, height=420,
                           visible=False)
        s_btn.click(do_search, [sq, ss], [s_md, s_gal])

    with gr.Tab("ℹ️ About"):
        gr.Markdown(ABOUT)

if __name__ == "__main__":
    demo.queue(max_size=20).launch()