Create timeline_generator.py

timeline_generator.py

@@ -0,0 +1,149 @@
+import graphviz
+import json
+from tempfile import NamedTemporaryFile
+import os
+
+def generate_timeline_diagram(json_input: str, output_format: str) -> str:
+    """
+    Generates a timeline diagram from JSON input.
+
+    Args:
+        json_input (str): A JSON string describing the timeline structure.
+                          It must follow the Expected JSON Format Example below.
+
+    Expected JSON Format Example:
+    {
+      "title": "AI Development Timeline",
+      "events": [
+        {
+          "id": "event_1",
+          "label": "Machine Learning Foundations",
+          "date": "1950-1960",
+          "description": "Early neural networks and perceptrons"
+        },
+        {
+          "id": "event_2",
+          "label": "Expert Systems Era",
+          "date": "1970-1980",
+          "description": "Rule-based AI systems"
+        },
+        {
+          "id": "event_3",
+          "label": "Neural Network Revival",
+          "date": "1980-1990",
+          "description": "Backpropagation algorithm"
+        }
+      ]
+    }
+
+    Returns:
+        str: The filepath to the generated PNG image file.
+    """
+    try:
+        if not json_input.strip():
+            return "Error: Empty input"
+            
+        data = json.loads(json_input)
+        
+        if 'events' not in data:
+            raise ValueError("Missing required field: events")
+
+        dot = graphviz.Digraph(
+            name='Timeline',
+            format='png',
+            graph_attr={
+                'rankdir': 'LR',        # Left-to-Right layout (horizontal timeline)
+                'splines': 'ortho',     # Straight lines
+                'bgcolor': 'white',     # White background
+                'pad': '0.5',           # Padding around the graph
+                'nodesep': '1.0',       # Spacing between nodes
+                'ranksep': '2.0'        # Spacing between ranks
+            }
+        )
+        
+        base_color = '#19191a' # Hardcoded base color
+        
+        title = data.get('title', '')
+        events = data.get('events', [])
+        
+        if not events:
+            raise ValueError("Timeline must contain at least one event")
+
+        # Add title node if provided
+        if title:
+            dot.node(
+                'title',
+                title,
+                shape='plaintext',
+                fontsize='18',
+                fontweight='bold',
+                fontcolor=base_color
+            )
+        
+        # Add timeline events
+        previous_event_id = None
+        total_events = len(events)
+        
+        for i, event in enumerate(events):
+            event_id = event.get('id', f'event_{i}')
+            event_label = event.get('label', f'Event {i+1}')
+            event_date = event.get('date', '')
+            event_description = event.get('description', '')
+            
+            # Create full label with date and description
+            if event_date and event_description:
+                full_label = f"{event_date}\\n{event_label}\\n{event_description}"
+            elif event_date:
+                full_label = f"{event_date}\\n{event_label}"
+            elif event_description:
+                full_label = f"{event_label}\\n{event_description}"
+            else:
+                full_label = event_label
+            
+            # Calculate color opacity based on position in timeline
+            if total_events == 1:
+                opacity = 'FF'
+            else:
+                opacity_value = int(255 * (1.0 - (i * 0.7 / (total_events - 1))))
+                opacity = format(opacity_value, '02x')
+            
+            node_color = f"{base_color}{opacity}"
+            font_color = 'white' if i < total_events * 0.7 else 'black'
+            
+            # Add the event node
+            dot.node(
+                event_id,
+                full_label,
+                shape='box',
+                style='filled,rounded',
+                fillcolor=node_color,
+                fontcolor=font_color,
+                fontsize='12',
+                width='2.5',
+                height='1.2'
+            )
+            
+            # Connect to previous event if exists
+            if previous_event_id:
+                dot.edge(
+                    previous_event_id,
+                    event_id,
+                    color='#666666',
+                    arrowsize='0.8',
+                    penwidth='2'
+                )
+            
+            # Connect title to first event if title exists
+            if title and i == 0:
+                dot.edge('title', event_id, style='invis')
+            
+            previous_event_id = event_id
+
+        with NamedTemporaryFile(delete=False, suffix=f'.{output_format}') as tmp:
+            dot.render(tmp.name, format=output_format, cleanup=True)
+            return f"{tmp.name}.{output_format}"
+
+    except json.JSONDecodeError:
+        return "Error: Invalid JSON format"
+    except Exception as e:
+        return f"Error: {str(e)}"