update the language of the report

backend/app/models/report.py

@@ -43,6 +43,7 @@ class ScenarioReportData(BaseModel):
 
 class ReportRequest(BaseModel):
     """Input for report generation."""
+    language: str = "en"
     # Project metadata
     project_notes: str = ""
     pinch_notes: str = ""

backend/app/services/report_service.py

@@ -12,6 +12,85 @@ from app.models.report import ReportRequest, ScenarioReportData, ReportStream
 from app.services.map_service import generate_process_map_b64
 
 
+I18N = {
+    "en": {
+        "report_title": "Heat Integration Report",
+        "generated": "Generated",
+        "data_collection": "Data Collection",
+        "process_maps": "Process Level Maps",
+        "collected_data": "Collected Data",
+        "notes": "Data Collection Notes",
+        "no_notes": "No notes recorded.",
+        "process": "Process",
+        "subprocess": "Subprocess",
+        "stream": "Stream",
+        "type": "Type",
+        "hot": "Hot",
+        "cold": "Cold",
+        "analysis": "Analysis",
+        "not_enough_streams": "Not enough streams selected for pinch analysis in this scenario.",
+        "min_heating": "Min. Heating Demand",
+        "min_cooling": "Min. Cooling Demand",
+        "pinch_temp": "Pinch Temperature",
+        "heat_recovery": "Heat Recovery",
+        "comparison": "Comparison",
+        "status_quo": "Status Quo",
+        "savings": "Savings",
+        "hp_hdr": "HP Coverage",
+        "hp_hdr_kw": "HP – {name} (kW)",
+        "hp_integration": "Heat Pump Integration",
+        "hp_table_hdr": "Heat Pump",
+        "diagrams": "Diagrams",
+        "interval_diagram": "Interval Diagram",
+        "scenario": "Scenario",
+        "comparison_summary": "Scenario Comparison",
+        "utilities_comparison": "Utilities Comparison",
+        "composite_title": "Composite Curves",
+        "gcc_title": "Grand Composite Curve",
+        "hpi_title": "Heat Pump Integration",
+        "selected_streams": "Selected Streams",
+        "process_layout": "Process Layout"
+    },
+    "de": {
+        "report_title": "Wärmeintegrationsbericht",
+        "generated": "Generiert",
+        "data_collection": "Datenerfassung",
+        "process_maps": "Prozesskarten",
+        "collected_data": "Erfasste Daten",
+        "notes": "Notizen zur Datenerfassung",
+        "no_notes": "Keine Notizen erfasst.",
+        "process": "Prozess",
+        "subprocess": "Teilprozess",
+        "stream": "Strom",
+        "type": "Typ",
+        "hot": "Heiß",
+        "cold": "Kalt",
+        "analysis": "Analyse",
+        "not_enough_streams": "Nicht genügend Ströme für die Pinch-Analyse in diesem Szenario ausgewählt.",
+        "min_heating": "Min. Heizbedarf",
+        "min_cooling": "Min. Kühlbedarf",
+        "pinch_temp": "Pinch-Temperatur",
+        "heat_recovery": "Wärmerückgewinnung",
+        "comparison": "Vergleich",
+        "status_quo": "Status Quo",
+        "savings": "Einsparung",
+        "hp_hdr": "WP-Abdeckung",
+        "hp_hdr_kw": "WP – {name} (kW)",
+        "hp_integration": "Wärmepumpen-Integration",
+        "hp_table_hdr": "Wärmepumpe",
+        "diagrams": "Diagramme",
+        "interval_diagram": "Intervalldiagramm",
+        "scenario": "Szenario",
+        "comparison_summary": "Szenarienvergleich",
+        "utilities_comparison": "Vergleich der Versorgungsleistungen",
+        "composite_title": "Verbundkurven",
+        "gcc_title": "Grand-Composite-Kurve",
+        "hpi_title": "Wärmepumpen-Integration",
+        "selected_streams": "Ausgewählte Ströme",
+        "process_layout": "Prozess-Layout"
+    }
+}
+
 def _fmt(val: Any, decimals: int = 2) -> str:
     """Format a numeric value, return '' if None."""
     if val is None or val == '':
@@ -31,15 +110,17 @@ def _render_pinch_content(
     heat_pumps: List[Any],
     energy_demands: List[Any],
     map_streams_img_html: str,
+    lang: str = "en",
     include_plotly_js: bool = False
 ) -> str:
     """Helper to render the detailed analysis content for a single scenario."""
+    texts = I18N.get(lang, I18N["en"])
     
     if not pinch_result or len(selected_streams) < 2:
         return f"""
         <div id="{id_slug}" class="page-content">
-            <h2>📊 Analysis: {name}</h2>
-            <p><em>Not enough streams selected for pinch analysis in this scenario.</em></p>
+            <h2>📊 {texts['analysis']}: {name}</h2>
+            <p><em>{texts['not_enough_streams']}</em></p>
         </div>
         """
 
@@ -50,26 +131,27 @@ def _render_pinch_content(
     # Streams table
     rows = ""
     for s in selected_streams:
-        badge_cls = "hot" if s.Tin > s.Tout else "cold"
-        badge_lbl = "Hot" if s.Tin > s.Tout else "Cold"
+        is_hot = s.Tin > s.Tout
+        badge_cls = "hot" if is_hot else "cold"
+        badge_lbl = texts['hot'] if is_hot else texts['cold']
         rows += (
             f"<tr><td>{s.name}</td><td>{s.Tin:.1f}</td><td>{s.Tout:.1f}</td>"
             f"<td>{s.CP:.2f}</td><td>{s.Q:.2f}</td>"
             f"<td><span class='badge {badge_cls}'>{badge_lbl}</span></td></tr>\n"
         )
     streams_table = (
-        "<table class='data-table'><thead><tr>"
-        "<th>Stream</th><th>Tin (°C)</th><th>Tout (°C)</th><th>CP (kW/K)</th><th>Q (kW)</th><th>Type</th>"
-        "</tr></thead><tbody>" + rows + "</tbody></table>"
+        f"<table class='data-table'><thead><tr>"
+        f"<th>{texts['stream']}</th><th>Tin (°C)</th><th>Tout (°C)</th><th>CP (kW/K)</th><th>Q (kW)</th><th>{texts['type']}</th>"
+        f"</tr></thead><tbody>" + rows + "</tbody></table>"
     )
 
     # Metrics
     metrics_html = f"""
     <div class="metrics-row">
-      <div class="metric-card hot"><div class="metric-label">Min. Heating Demand</div><div class="metric-value">{pr.hot_utility:.2f} kW</div></div>
-      <div class="metric-card cold"><div class="metric-label">Min. Cooling Demand</div><div class="metric-value">{pr.cold_utility:.2f} kW</div></div>
-      <div class="metric-card pinch"><div class="metric-label">Pinch Temperature</div><div class="metric-value">{pr.pinch_temperature:.1f} °C</div></div>
-      <div class="metric-card recovery"><div class="metric-label">Heat Recovery</div><div class="metric-value">{heat_recovery:.2f} kW</div></div>
+      <div class="metric-card hot"><div class="metric-label">{texts['min_heating']}</div><div class="metric-value">{pr.hot_utility:.2f} kW</div></div>
+      <div class="metric-card cold"><div class="metric-label">{texts['min_cooling']}</div><div class="metric-value">{pr.cold_utility:.2f} kW</div></div>
+      <div class="metric-card pinch"><div class="metric-label">{texts['pinch_temp']}</div><div class="metric-value">{pr.pinch_temperature:.1f} °C</div></div>
+      <div class="metric-card recovery"><div class="metric-label">{texts['heat_recovery']}</div><div class="metric-value">{heat_recovery:.2f} kW</div></div>
     </div>"""
 
     # Comparison table (Status Quo vs Proposal)
@@ -87,22 +169,22 @@ def _render_pinch_content(
         if best and best.q_sink is not None and best.q_source is not None:
             hc_heat = min(best.q_sink, pr.hot_utility)
             hc_cool = min(best.q_source, pr.cold_utility)
-            hp_hdr = f"HP – {best.name} (kW)"
+            hp_hdr = texts['hp_hdr_kw'].format(name=best.name)
             hc_h_s = f"{hc_heat:.1f}"
             hc_c_s = f"{hc_cool:.1f}"
             hc_h_p = f"{hc_heat/pr.hot_utility*100:.1f}%" if pr.hot_utility > 0 else "N/A"
             hc_c_p = f"{hc_cool/pr.cold_utility*100:.1f}%" if pr.cold_utility > 0 else "N/A"
         else:
-            hp_hdr = "HP Coverage (kW)"
+            hp_hdr = f"{texts['hp_hdr']} (kW)"
             hc_h_s = hc_c_s = hc_h_p = hc_c_p = "N/A"
 
         comparison_html = f"""
-        <h3>&#x1F4CA; Comparison: Status Quo vs {name}</h3>
+        <h3>📊 {texts['comparison']}: {texts['status_quo']} vs {name}</h3>
         <table class='data-table'>
-          <thead><tr><th>Type</th><th>Status Quo (kW)</th><th>Min. after HR (kW)</th><th>Savings (kW)</th><th>Savings (%)</th><th>{hp_hdr}</th><th>HP Coverage (%)</th></tr></thead>
+          <thead><tr><th>{texts['type']}</th><th>{texts['status_quo']} (kW)</th><th>Min. after HR (kW)</th><th>{texts['savings']} (kW)</th><th>{texts['savings']} (%)</th><th>{hp_hdr}</th><th>{texts['hp_hdr']} (%)</th></tr></thead>
           <tbody>
-            <tr><td>Heating</td><td>{tot_heat:.1f}</td><td>{pr.hot_utility:.1f}</td><td>{sh:.1f}</td><td>{sh_pct}</td><td>{hc_h_s}</td><td>{hc_h_p}</td></tr>
-            <tr><td>Cooling</td><td>{tot_cool:.1f}</td><td>{pr.cold_utility:.1f}</td><td>{sc:.1f}</td><td>{sc_pct}</td><td>{hc_c_s}</td><td>{hc_c_p}</td></tr>
+            <tr><td>{texts['hot']}</td><td>{tot_heat:.1f}</td><td>{pr.hot_utility:.1f}</td><td>{sh:.1f}</td><td>{sh_pct}</td><td>{hc_h_s}</td><td>{hc_h_p}</td></tr>
+            <tr><td>{texts['cold']}</td><td>{tot_cool:.1f}</td><td>{pr.cold_utility:.1f}</td><td>{sc:.1f}</td><td>{sc_pct}</td><td>{hc_c_s}</td><td>{hc_c_p}</td></tr>
           </tbody>
         </table>"""
 
@@ -117,9 +199,9 @@ def _render_pinch_content(
         )
     if hp_rows:
         hp_table_html = f"""
-        <h3>Heat Pump Integration ({name})</h3>
+        <h3>{texts['hp_integration']} ({name})</h3>
         <table class='data-table'>
-          <thead><tr><th>Heat Pump</th><th>COP</th><th>T_source (°C)</th><th>T_sink (°C)</th><th>Q_source (kW)</th><th>Q_sink (kW)</th></tr></thead>
+          <thead><tr><th>{texts['hp_table_hdr']}</th><th>COP</th><th>T_source (°C)</th><th>T_sink (°C)</th><th>Q_source (kW)</th><th>Q_sink (kW)</th></tr></thead>
           <tbody>{hp_rows}</tbody>
         </table>"""
 
@@ -135,10 +217,10 @@ def _render_pinch_content(
     # Composite
     if pr.composite_diagram.hot.get("H"):
         fig = go.Figure()
-        fig.add_trace(go.Scatter(x=pr.composite_diagram.hot["H"], y=pr.composite_diagram.hot["T"], mode='lines+markers', name='Hot Streams', line=dict(color='red')))
-        fig.add_trace(go.Scatter(x=pr.composite_diagram.cold["H"], y=pr.composite_diagram.cold["T"], mode='lines+markers', name='Cold Streams', line=dict(color='blue')))
+        fig.add_trace(go.Scatter(x=pr.composite_diagram.hot["H"], y=pr.composite_diagram.hot["T"], mode='lines+markers', name=texts['hot'], line=dict(color='red')))
+        fig.add_trace(go.Scatter(x=pr.composite_diagram.cold["H"], y=pr.composite_diagram.cold["T"], mode='lines+markers', name=texts['cold'], line=dict(color='blue')))
         fig.add_hline(y=pr.pinch_temperature, line_dash='dash', line_color='gray', annotation_text="Pinch")
-        fig.update_layout(**chart_layout_base, title='Composite Curves', xaxis_title='H (kW)', yaxis_title='T (°C)')
+        fig.update_layout(**chart_layout_base, title=texts['composite_title'], xaxis_title='H (kW)', yaxis_title='T (°C)')
         comp_html = fig.to_html(full_html=False, include_plotlyjs=include_js)
 
     # GCC
@@ -148,7 +230,6 @@ def _render_pinch_content(
         hc = pr.heat_cascade
         fig = go.Figure()
         for i in range(len(gcc_H) - 1):
-            # Color based on deltaH in the cascade: > 0 is heating (red), < 0 is cooling (blue)
             seg_color = 'red' if i < len(hc) and hc[i].get('deltaH', 0) > 0 else ('blue' if i < len(hc) and hc[i].get('deltaH', 0) < 0 else 'gray')
             fig.add_trace(go.Scatter(
                 x=[gcc_H[i], gcc_H[i+1]], 
@@ -160,7 +241,7 @@ def _render_pinch_content(
             ))
         fig.add_hline(y=pr.pinch_temperature, line_dash='dash', annotation_text="Pinch")
         fig.add_vline(x=0, line_color='black', line_width=1, opacity=0.3)
-        fig.update_layout(**chart_layout_base, title='Grand Composite Curve', xaxis_title='Net ΔH (kW)', yaxis_title='Shifted T (°C)')
+        fig.update_layout(**chart_layout_base, title=texts['gcc_title'], xaxis_title='Net ΔH (kW)', yaxis_title='Shifted T (°C)')
         gcc_html = fig.to_html(full_html=False, include_plotlyjs=False)
 
     # HPI
@@ -170,7 +251,6 @@ def _render_pinch_content(
         hc = pr.heat_cascade
         fig = go.Figure()
         
-        # Add color-coded GCC background
         for i in range(len(gcc_H) - 1):
             seg_color = 'rgba(255, 0, 0, 0.4)' if i < len(hc) and hc[i].get('deltaH', 0) > 0 else ('rgba(0, 0, 255, 0.4)' if i < len(hc) and hc[i].get('deltaH', 0) < 0 else 'rgba(128, 128, 128, 0.4)')
             fig.add_trace(go.Scatter(
@@ -186,7 +266,7 @@ def _render_pinch_content(
         for idx, hp in enumerate([h for h in heat_pumps if h.available][:3]):
             c = hp_colors[idx % len(hp_colors)]
             fig.add_trace(go.Scatter(x=[hp.q_source, hp.q_sink], y=[hp.t_source, hp.t_sink], mode='markers', marker=dict(size=12, color=c, symbol='diamond'), name=hp.name))
-        fig.update_layout(**chart_layout_base, title='Heat Pump Integration')
+        fig.update_layout(**chart_layout_base, title=texts['hpi_title'])
         hpi_html = fig.to_html(full_html=False, include_plotlyjs=False)
 
     # Interval
@@ -195,22 +275,22 @@ def _render_pinch_content(
         for i, strm in enumerate(pr.streams_data):
             color = 'red' if strm.get('type') == 'HOT' else 'blue'
             fig.add_trace(go.Scatter(x=[i+1, i+1], y=[strm.get('ss'), strm.get('st')], mode='lines', line=dict(color=color, width=10)))
-        fig.update_layout(**chart_layout_base, title='Interval Diagram')
+        fig.update_layout(**chart_layout_base, title=texts['interval_diagram'])
         int_html = fig.to_html(full_html=False, include_plotlyjs=False)
 
     return f"""
     <div id="{id_slug}" class="page-content">
-        <h2>📊 Analysis: {name} (ΔTmin = {t_min}°C)</h2>
+        <h2>📊 {texts['analysis']}: {name} (ΔTmin = {t_min}°C)</h2>
         
         <div class="stream-map-layout">
-            <div class="stream-list-section"><h4>Selected Streams</h4>{streams_table}</div>
-            <div class="map-display-section"><h4>Process Layout</h4>{map_streams_img_html}</div>
+            <div class="stream-list-section"><h4>{texts['selected_streams']}</h4>{streams_table}</div>
+            <div class="map-display-section"><h4>{texts['process_layout']}</h4>{map_streams_img_html}</div>
         </div>
 
         {metrics_html}
         {comparison_html}
 
-        <h3>Diagrams</h3>
+        <h3>{texts['diagrams']}</h3>
         <div class="plots-container">
             <div class="plot-section">{comp_html}</div>
             <div class="plot-section">{gcc_html}</div>
@@ -219,26 +299,29 @@ def _render_pinch_content(
             <div class="hpi-table-col">{hp_table_html}</div>
             <div class="hpi-chart-col"><div class="plot-section">{hpi_html}</div></div>
         </div>
-        <h3>Interval Diagram</h3>
+        <h3>{texts['interval_diagram']}</h3>
         <div class="plot-section" style="width:100%">{int_html}</div>
     </div>
     """
 
 
+
 def generate_html_report(req: ReportRequest) -> str:
     """Generate a multi-page self-contained HTML report."""
     now_str = datetime.now().strftime('%Y-%m-%d %H:%M')
+    lang = req.language if req.language in I18N else "en"
+    texts = I18N[lang]
 
     # 1. Map images (Project-wide - Data Collection)
     original_base = req.current_base
     
     req.current_base = 'OpenStreetMap'
     osm_overlaid_b64 = generate_process_map_b64(req)
-    map_osm_html = f"<img src='data:image/png;base64,{osm_overlaid_b64}' alt='OSM'>" if osm_overlaid_b64 else "<p>Map not available</p>"
+    map_osm_html = f"<img src='data:image/png;base64,{osm_overlaid_b64}' alt='OSM'>" if osm_overlaid_b64 else f"<p>{texts['process_maps']} N/A</p>"
     
     req.current_base = 'Satellite'
     sat_overlaid_b64 = generate_process_map_b64(req)
-    map_sat_html = f"<img src='data:image/png;base64,{sat_overlaid_b64}' alt='Satellite'>" if sat_overlaid_b64 else "<p>Satellite map not available</p>"
+    map_sat_html = f"<img src='data:image/png;base64,{sat_overlaid_b64}' alt='Satellite'>" if sat_overlaid_b64 else f"<p>{texts['process_maps']} N/A</p>"
     
     req.current_base = original_base
 
@@ -254,15 +337,19 @@ def generate_html_report(req: ReportRequest) -> str:
             mdot, cp = sv.get('ṁ', s.get('mdot', '')), sv.get('cp', s.get('cp', ''))
             CP = sv.get('CP', '')
             Q = f"{(float(mdot)*float(cp)*abs(float(tout)-float(tin))):.2f}" if (tin and tout and mdot and cp) else ""
+            
+            s_type = s.get('type', '')
+            localized_type = texts['hot'] if s_type == 'HOT' else (texts['cold'] if s_type == 'COLD' else s_type)
+            
             data_rows += (
                 f"<tr><td>{process_name}</td><td>{sp.name}</td><td>{s.get('name')}</td>"
-                f"<td>{s.get('type')}</td><td>{tin}</td><td>{tout}</td><td>{mdot}</td>"
+                f"<td>{localized_type}</td><td>{tin}</td><td>{tout}</td><td>{mdot}</td>"
                 f"<td>{cp}</td><td>{CP}</td><td>{Q}</td></tr>"
             )
 
     # 3. Compile Individual Scenario Pages
     scenario_pages_html = ""
-    nav_links_html = f'<li class="nav-tab active" onclick="showPage(\'data-collection\')">📍 Data Collection</li>'
+    nav_links_html = f'<li class="nav-tab active" onclick="showPage(\'data-collection\')">📍 {texts["data_collection"]}</li>'
     
     # Render each saved scenario
     for i, sc in enumerate(req.scenarios):
@@ -279,13 +366,14 @@ def generate_html_report(req: ReportRequest) -> str:
         # The first scenario page must include Plotly.js to enable charts across all tabs
         scenario_pages_html += _render_pinch_content(
             sc.name, sc_id, sc.t_min, sc.pinch_result, sc.selected_streams, sc.heat_pumps, sc.energy_demands, sc_map_html,
+            lang=lang,
             include_plotly_js=(i == 0)
         )
 
     # 4. Comparison Summary Page
     comparison_html = ""
     if req.scenarios:
-        nav_links_html += f'<li class="nav-tab" onclick="showPage(\'comparison-summary\')">⚖️ Comparison</li>'
+        nav_links_html += f'<li class="nav-tab" onclick="showPage(\'comparison-summary\')">⚖️ {texts["comparison"]}</li>'
         sc_rows = ""
         sc_names, sc_hot, sc_cold = [], [], []
         for sc in req.scenarios:
@@ -294,25 +382,25 @@ def generate_html_report(req: ReportRequest) -> str:
             sc_names.append(sc.name); sc_hot.append(phu); sc_cold.append(pcu)
             sc_rows += f"<tr><td><strong>{sc.name}</strong></td><td>{sc.t_min}K</td><td>{phu:.1f} kW</td><td>{pcu:.1f} kW</td></tr>"
         
-        fig = go.Figure([go.Bar(x=sc_names, y=sc_hot, name='Heating', marker_color='#ef4444'), go.Bar(x=sc_names, y=sc_cold, name='Cooling', marker_color='#3b82f6')])
-        fig.update_layout(height=400, barmode='group', title="Utilities Comparison")
+        fig = go.Figure([go.Bar(x=sc_names, y=sc_hot, name=texts['hot'], marker_color='#ef4444'), go.Bar(x=sc_names, y=sc_cold, name=texts['cold'], marker_color='#3b82f6')])
+        fig.update_layout(height=400, barmode='group', title=texts['utilities_comparison'])
         comp_chart = fig.to_html(full_html=False, include_plotlyjs=False)
 
         comparison_html = f"""
         <div id="comparison-summary" class="page-content">
-            <h2>⚖️ Scenario Comparison</h2>
+            <h2>⚖️ {texts['comparison_summary']}</h2>
             <div class="plot-section">{comp_chart}</div>
             <table class="data-table">
-                <thead><tr><th>Scenario</th><th>ΔTmin</th><th>Min. Heating</th><th>Min. Cooling</th></tr></thead>
+                <thead><tr><th>{texts['scenario']}</th><th>ΔTmin</th><th>{texts['min_heating']}</th><th>{texts['min_cooling']}</th></tr></thead>
                 <tbody>{sc_rows}</tbody>
             </table>
         </div>"""
 
     # Final HTML assembly
-    return f"""<!DOCTYPE html>
-<html lang="en">
+    html = f"""<!DOCTYPE html>
+<html lang="{lang}">
 <head>
-<meta charset="UTF-8"><title>Heat Integration Report</title>
+<meta charset="UTF-8"><title>{texts['report_title']}</title>
 <style>
     body {{ font-family: 'Segoe UI', sans-serif; background:#f5f5f5; margin:0; padding:20px; }}
     .report-container {{ background:#fff; padding:30px; border-radius:8px; max-width:2400px; margin:auto; box-shadow:0 2px 10px rgba(0,0,0,0.1); }}
@@ -346,23 +434,23 @@ def generate_html_report(req: ReportRequest) -> str:
 </head>
 <body>
 <div class="report-container">
-    <h1>Heat Integration Report</h1>
-    <p style="color:#666">Generated: {now_str}</p>
+    <h1>{texts['report_title']}</h1>
+    <p style="color:#666">{texts['generated']}: {now_str}</p>
     <ul class="nav-tabs">{nav_links_html}</ul>
     
     <div id="data-collection" class="page-content active">
-        <h2>📍 Data Collection</h2>
-        <h3>Process Level Maps</h3>
+        <h2>📍 {texts['data_collection']}</h2>
+        <h3>{texts['process_maps']}</h3>
         <div class="maps-container">
           <div class="map-section">{map_osm_html}<p>OpenStreetMap</p></div>
           <div class="map-section">{map_sat_html}<p>Satellite</p></div>
         </div>
-        <h3>📋 Collected Data</h3>
+        <h3>📋 {texts['collected_data']}</h3>
         <table class="data-table">
-            <thead><tr><th>Process</th><th>Subprocess</th><th>Stream</th><th>Type</th><th>Tin (°C)</th><th>Tout (°C)</th><th>ṁ</th><th>cp</th><th>CP</th><th>Q (kW)</th></tr></thead>
+            <thead><tr><th>{texts['process']}</th><th>{texts['subprocess']}</th><th>{texts['stream']}</th><th>{texts['type']}</th><th>Tin (°C)</th><th>Tout (°C)</th><th>ṁ</th><th>cp</th><th>CP</th><th>Q (kW)</th></tr></thead>
             <tbody>{data_rows}</tbody>
         </table>
-        <h3>📝 Data Collection Notes</h3><div style="background:#f9f9f9; padding:15px; border-left:4px solid #3498db; white-space: pre-wrap;">{req.project_notes or 'No notes recorded.'}</div>
+        <h3>📝 {texts['notes']}</h3><div style="background:#f9f9f9; padding:15px; border-left:4px solid #3498db; white-space: pre-wrap;">{req.project_notes or texts['no_notes']}</div>
     </div>
 
     {scenario_pages_html}
@@ -374,7 +462,6 @@ function showPage(id) {{
     document.querySelectorAll('.nav-tab').forEach(t => t.classList.remove('active'));
     document.getElementById(id).classList.add('active');
     
-    // Select the correct tab based on the ID passed
     const tabs = document.querySelectorAll('.nav-tab');
     tabs.forEach(t => {{
         if (t.getAttribute('onclick').includes(id)) t.classList.add('active');
@@ -386,3 +473,4 @@ function showPage(id) {{
 </body></html>"""
 
     return html
+

frontend/src/pages/PotentialAnalysisPage.tsx

@@ -34,7 +34,7 @@ import AnalysisHelp from '../components/ui/AnalysisHelp';
 import ChartHelpButton from '../components/ui/ChartHelpButton';
 
 export default function PotentialAnalysisPage() {
-  const { t } = useTranslation();
+  const { t, i18n } = useTranslation();
   const processes = useProjectStore((s) => s.state.processes);
   const pinchNotes = useProjectStore((s) => s.state.pinch_notes);
   const setPinchNotes = useProjectStore((s) => s.setPinchNotes);
@@ -311,6 +311,7 @@ export default function PotentialAnalysisPage() {
   // Helper to build payload for report and map preview
   const buildReportPayload = useCallback(() => {
     return {
+      language: i18n.language || 'en',
       project_notes: projectState.project_notes || '',
       pinch_notes: projectState.pinch_notes || '',
       map_snapshots_encoded: projectState.map_snapshots_encoded || {},