Update app.py

app.py

@@ -1,6 +1,8 @@
+# app.py
 import os
 import tempfile
 import pathlib
+import hashlib
 import gradio as gr
 import numpy as np
 
@@ -8,6 +10,8 @@ from quread.engine import QuantumStateVector
 from quread.exporters import to_openqasm2, to_qiskit, to_cirq
 from quread.llm_explain_openai import explain_with_gpt4o
 from quread.circuit_diagram import draw_circuit_svg
+from quread.cost_guard import allow_request
+from quread.export_pdf import md_to_pdf
 
 
 # ---------- Helpers ----------
@@ -40,6 +44,10 @@ def _write_tmp(filename: str, content: str) -> str:
     return str(p)
 
 
+def _circuit_hash(history):
+    return hashlib.sha256(str(history).encode()).hexdigest()
+
+
 def dl_qasm(qc, n_qubits):
     return _write_tmp("circuit.qasm", to_openqasm2(qc.history, n_qubits=int(n_qubits)))
 
@@ -94,25 +102,31 @@ def measure_collapse(qc, shots):
     return last_counts, f"✅ Collapsed to |{res}⟩ and sampled shots."
 
 
-def explain_llm(qc, n_qubits, shots, hf_model_id):
+def explain_llm(qc, n_qubits, shots, last_hash):
+    # circuit-change gating
+    curr_hash = _circuit_hash(qc.history)
+    if curr_hash == last_hash:
+        return "ℹ️ Circuit unchanged. Explanation reused.", last_hash, ""
+
+    # cost guard
+    EST_TOKENS = 900
+    if not allow_request(EST_TOKENS):
+        return "🚫 Explanation disabled (daily token limit reached).", last_hash, ""
+
     state_ket = qc.ket_notation(max_terms=6)
     probs_top = _probs_top(qc, int(n_qubits), k=6)
 
-    cfg = ExplainConfig(
-        model_id=hf_model_id.strip(),
-        max_new_tokens=280,
-        temperature=0.2,
-    )
-
-    return explain_circuit_with_hf(
+    explanation = explain_with_gpt4o(
         n_qubits=int(n_qubits),
         history=qc.history,
         state_ket=state_ket,
         probs_top=probs_top,
         shots=int(shots),
-        cfg=cfg,
     )
 
+    return explanation, curr_hash, explanation
+
+
 def _refresh_choices(n):
     opts = list(range(int(n)))
     return (
@@ -122,7 +136,7 @@ def _refresh_choices(n):
     )
 
 
-# ---------- Streamlit-like styling ----------
+# ---------- Styling ----------
 CSS = """
 #title h1 { font-size: 42px !important; margin-bottom: 6px; }
 #subtitle { color: #6b7280; margin-top: 0px; }
@@ -147,33 +161,31 @@ CSS = """
 
 theme = gr.themes.Soft(radius_size="lg", text_size="md")
 
+
 with gr.Blocks(theme=theme, css=CSS, title="Quread.ai — State Vector Studio") as demo:
     qc_state = gr.State()
     last_counts_state = gr.State()
     selected_gate_state = gr.State()
+    explanation_md = gr.State("")
+    last_explained_hash = gr.State("")
 
     with gr.Row():
-        # ----- Sidebar -----
+        # Sidebar
         with gr.Column(scale=3, elem_classes=["sidebar"]):
             gr.Markdown("### Simulator Settings")
             n_qubits = gr.Slider(1, 10, value=2, step=1, label="Number of qubits")
-            shots = gr.Slider(128, 8192, value=1024, step=128, label="Shots (for sampling)")
+            shots = gr.Slider(128, 8192, value=1024, step=128, label="Shots")
 
             gr.Markdown("---")
-            gr.Markdown("### LLM Explanation (Hugging Face)")
-            hf_model_id = gr.Textbox(
-                value="optimum/t5-small",
-                label="HF model repo id",
-            )
-            gr.Markdown("<div class='small-note'>Set secret in HF Space: <b>HF_TOKEN</b></div>")
+            gr.Markdown("### Explanation (GPT-4o)")
+            gr.Markdown("<div class='small-note'>Uses GPT-4o with cost guards.</div>")
 
             reset_btn = gr.Button("Reset Simulator", variant="secondary")
 
-        # ----- Main content -----
+        # Main
         with gr.Column(scale=9):
-            gr.Markdown("<div id='title'><h1>Quread.ai — State Vector Studio (Dev Tool Edition)</h1></div>")
-            gr.Markdown("<div id='subtitle'>Build circuits, inspect the statevector, visualize the circuit, export to QASM/Qiskit/Cirq, and get grounded explanations.</div>")
-
+            gr.Markdown("<div id='title'><h1>Quread.ai — State Vector Studio</h1></div>")
+            gr.Markdown("<div id='subtitle'>Build circuits, visualize, export, and get teaching-ready explanations.</div>")
             status = gr.Markdown("")
 
             with gr.Group(elem_classes=["card"]):
@@ -186,7 +198,7 @@ with gr.Blocks(theme=theme, css=CSS, title="Quread.ai — State Vector Studio")
                     gate_S = gr.Button("S")
                     gate_T = gr.Button("T")
 
-                target = gr.Dropdown(choices=[0, 1], value=0, label="Target qubit for single-qubit gates")
+                target = gr.Dropdown(choices=[0, 1], value=0, label="Target qubit")
 
                 with gr.Row():
                     apply_gate_btn = gr.Button("Apply Selected Gate", variant="primary")
@@ -199,30 +211,23 @@ with gr.Blocks(theme=theme, css=CSS, title="Quread.ai — State Vector Studio")
                     cnot_target = gr.Dropdown(choices=[0, 1], value=1, label="Target")
                     apply_cnot_btn = gr.Button("Apply CNOT")
 
-            # Circuit diagram card (missing before)
             with gr.Group(elem_classes=["card"]):
                 gr.Markdown("<div class='section-title'>Circuit Diagram</div>")
                 circuit_html = gr.HTML()
 
-            # Outputs
             with gr.Row():
                 with gr.Column(scale=7):
                     with gr.Group(elem_classes=["card"]):
-                        gr.Markdown("<div class='section-title'>Statevector (human-readable)</div>")
+                        gr.Markdown("<div class='section-title'>Statevector</div>")
                         ket_out = gr.Code(label="", language="python")
                         gr.Markdown("<div class='section-title'>Top probabilities</div>")
-                        probs_out = gr.Dataframe(headers=["bitstring", "prob"], label="", interactive=False)
+                        probs_out = gr.Dataframe(headers=["bitstring", "prob"], interactive=False)
 
                 with gr.Column(scale=5):
                     with gr.Group(elem_classes=["card"]):
                         gr.Markdown("<div class='section-title'>Measurement distribution</div>")
-                        counts_out = gr.Textbox(
-                            label="",
-                            lines=10,
-                            placeholder="Click 'Sample shots' or 'Measure + Collapse' to generate counts.",
-                        )
+                        counts_out = gr.Textbox(lines=10)
 
-                    # Export as download buttons (instead of copy/paste boxes)
                     with gr.Group(elem_classes=["card"]):
                         gr.Markdown("<div class='section-title'>Export</div>")
                         qasm_dl = gr.DownloadButton("Download OpenQASM 2.0")
@@ -230,30 +235,39 @@ with gr.Blocks(theme=theme, css=CSS, title="Quread.ai — State Vector Studio")
                         cirq_dl = gr.DownloadButton("Download Cirq code")
 
             with gr.Group(elem_classes=["card"]):
-                gr.Markdown("<div class='section-title'>Explain (HF Inference)</div>")
-                explain_btn = gr.Button("Explain (LLM)", variant="primary")
-                llm_out = gr.Markdown("")
-                gr.Markdown("<div class='small-note'>Tip: Sample shots first for better explanations.</div>")
+                gr.Markdown("<div class='section-title'>Explain (GPT-4o)</div>")
+                explain_btn = gr.Button("Explain", variant="primary")
+                llm_out = gr.Markdown()
+                with gr.Row():
+                    dl_md = gr.DownloadButton("Download Explanation (Markdown)")
+                    dl_pdf = gr.DownloadButton("Download Explanation (PDF)")
+                gr.Markdown("<div class='small-note'>Tip: sample shots first.</div>")
 
     # init
     def _init_all(n):
         qc, last_counts, selected_gate = _new_sim(n)
         return qc, last_counts, selected_gate
 
-    demo.load(fn=_init_all, inputs=[n_qubits], outputs=[qc_state, last_counts_state, selected_gate_state]).then(
+    demo.load(
+        fn=_init_all,
+        inputs=[n_qubits],
+        outputs=[qc_state, last_counts_state, selected_gate_state],
+    ).then(
         fn=update_views,
         inputs=[qc_state, last_counts_state, n_qubits],
         outputs=[circuit_html, ket_out, counts_out, probs_out],
     )
 
-    # keep dropdowns synced with n_qubits
-    n_qubits.change(fn=_refresh_choices, inputs=[n_qubits], outputs=[target, control, cnot_target]).then(
+    n_qubits.change(
+        fn=_refresh_choices,
+        inputs=[n_qubits],
+        outputs=[target, control, cnot_target],
+    ).then(
         fn=update_views,
         inputs=[qc_state, last_counts_state, n_qubits],
         outputs=[circuit_html, ket_out, counts_out, probs_out],
     )
 
-    # reset
     reset_btn.click(
         fn=init_or_reset,
         inputs=[n_qubits],
@@ -264,7 +278,6 @@ with gr.Blocks(theme=theme, css=CSS, title="Quread.ai — State Vector Studio")
         outputs=[circuit_html, ket_out, counts_out, probs_out],
     )
 
-    # gate select
     gate_H.click(fn=lambda: set_gate("H"), outputs=[selected_gate_state, status])
     gate_X.click(fn=lambda: set_gate("X"), outputs=[selected_gate_state, status])
     gate_Y.click(fn=lambda: set_gate("Y"), outputs=[selected_gate_state, status])
@@ -272,7 +285,6 @@ with gr.Blocks(theme=theme, css=CSS, title="Quread.ai — State Vector Studio")
     gate_S.click(fn=lambda: set_gate("S"), outputs=[selected_gate_state, status])
     gate_T.click(fn=lambda: set_gate("T"), outputs=[selected_gate_state, status])
 
-    # apply gate
     apply_gate_btn.click(
         fn=apply_selected_gate,
         inputs=[qc_state, last_counts_state, selected_gate_state, target],
@@ -283,7 +295,6 @@ with gr.Blocks(theme=theme, css=CSS, title="Quread.ai — State Vector Studio")
         outputs=[circuit_html, ket_out, counts_out, probs_out],
     )
 
-    # cnot
     apply_cnot_btn.click(
         fn=apply_cnot,
         inputs=[qc_state, last_counts_state, control, cnot_target],
@@ -294,7 +305,6 @@ with gr.Blocks(theme=theme, css=CSS, title="Quread.ai — State Vector Studio")
         outputs=[circuit_html, ket_out, counts_out, probs_out],
     )
 
-    # sample
     sample_btn.click(
         fn=sample_shots,
         inputs=[qc_state, shots],
@@ -305,7 +315,6 @@ with gr.Blocks(theme=theme, css=CSS, title="Quread.ai — State Vector Studio")
         outputs=[circuit_html, ket_out, counts_out, probs_out],
     )
 
-    # measure
     measure_btn.click(
         fn=measure_collapse,
         inputs=[qc_state, shots],
@@ -316,17 +325,27 @@ with gr.Blocks(theme=theme, css=CSS, title="Quread.ai — State Vector Studio")
         outputs=[circuit_html, ket_out, counts_out, probs_out],
     )
 
-    # export downloads
     qasm_dl.click(fn=dl_qasm, inputs=[qc_state, n_qubits], outputs=[qasm_dl])
     qiskit_dl.click(fn=dl_qiskit, inputs=[qc_state, n_qubits], outputs=[qiskit_dl])
     cirq_dl.click(fn=dl_cirq, inputs=[qc_state, n_qubits], outputs=[cirq_dl])
 
-    # explain
     explain_btn.click(
         fn=explain_llm,
-        inputs=[qc_state, n_qubits, shots, hf_model_id],
-        outputs=[llm_out],
+        inputs=[qc_state, n_qubits, shots, last_explained_hash],
+        outputs=[llm_out, last_explained_hash, explanation_md],
     )
 
+    def dl_explain_md(md_text):
+        return _write_tmp("explanation.md", md_text)
+
+    def dl_explain_pdf(md_text):
+        path = pathlib.Path(tempfile.gettempdir()) / "explanation.pdf"
+        md_to_pdf(md_text, str(path))
+        return str(path)
+
+    dl_md.click(fn=dl_explain_md, inputs=[explanation_md], outputs=[dl_md])
+    dl_pdf.click(fn=dl_explain_pdf, inputs=[explanation_md], outputs=[dl_pdf])
+
+
 if __name__ == "__main__":
     demo.launch(server_name="0.0.0.0", server_port=7860)