Create process_flow_generator.py

process_flow_generator.py

@@ -0,0 +1,153 @@
+import graphviz
+import json
+from tempfile import NamedTemporaryFile
+import os
+from graph_generator_utils import add_nodes_and_edges # Reusing common utility
+
+def generate_process_flow_diagram(json_input: str, base_color: str) -> str:
+    """
+    Generates a Process Flow Diagram (Flowchart) from JSON input.
+
+    Args:
+        json_input (str): A JSON string describing the process flow structure.
+                          It must follow the Expected JSON Format Example below.
+        base_color (str): The hexadecimal color string (e.g., '#19191a') for the base
+                          color of the nodes, from which a gradient will be generated.
+
+    Returns:
+        str: The filepath to the generated PNG image file.
+
+    Expected JSON Format Example:
+    {
+      "start_node": "Start Process",
+      "nodes": [
+        {
+          "id": "step1",
+          "label": "Gather Requirements",
+          "type": "process",
+          "relationship": "Next",
+          "subnodes": [
+            {"id": "step1_1", "label": "Define Scope", "type": "process", "relationship": "Then"}
+          ]
+        },
+        {
+          "id": "decision1",
+          "label": "Is Data Available?",
+          "type": "decision",
+          "relationship": "Check",
+          "subnodes": [
+            {"id": "path_yes", "label": "Process Data", "type": "process", "relationship": "Yes"},
+            {"id": "path_no", "label": "Collect More Data", "type": "process", "relationship": "No"}
+          ]
+        },
+        {
+          "id": "end_node",
+          "label": "End Process",
+          "type": "end",
+          "relationship": "Concludes"
+        }
+      ],
+      "connections": [
+        {"from": "start_node", "to": "step1"},
+        {"from": "step1", "to": "decision1"},
+        {"from": "decision1", "to": "path_yes", "label": "Yes"},
+        {"from": "decision1", "to": "path_no", "label": "No"},
+        {"from": "path_yes", "to": "end_node"},
+        {"from": "path_no", "to": "end_node"}
+      ]
+    }
+    """
+    try:
+        if not json_input.strip():
+            return "Error: Empty input"
+            
+        data = json.loads(json_input)
+        
+        # Determine specific node shapes for flowchart types
+        node_shapes = {
+            "process": "box",
+            "decision": "diamond",
+            "start": "Mrecord", # Rounded box for start/end
+            "end": "Mrecord",    # Rounded box for start/end
+            "io": "parallelogram", # Input/Output
+            "document": "note",
+            "default": "box"
+        }
+
+        dot = graphviz.Digraph(
+            name='ProcessFlowDiagram',
+            format='png',
+            graph_attr={
+                'rankdir': 'TB',        # Top-to-Bottom flow is common for flowcharts
+                'splines': 'ortho',     # Straight lines with 90-degree bends
+                'bgcolor': 'white',     # White background
+                'pad': '0.5'            # Padding around the graph
+            },
+            node_attr={'style': 'filled,rounded', 'fontcolor': 'white', 'fontsize': '12'} # Default node style
+        )
+        
+        # Add all nodes based on JSON structure
+        all_nodes = {}
+        if 'start_node' in data:
+            all_nodes[data['start_node']] = {"label": data['start_node'], "type": "start"}
+        
+        for node_data in data.get('nodes', []):
+            all_nodes[node_data['id']] = node_data
+
+        # Add nodes with specific shapes and styles
+        for node_id, node_info in all_nodes.items():
+            node_type = node_info.get("type", "default")
+            shape = node_shapes.get(node_type, "box") # Default to box if type is unknown
+
+            # Calculate color for current node based on a simplified depth or fixed for process flow
+            # For simplicity in process flow, let's keep the base color for all primary nodes for now,
+            # or apply a subtle gradient if depth is truly defined in a meaningful way.
+            # Here, we'll use the base_color for all nodes, making the color selection more direct.
+            
+            # Simple color lightening for sub-levels if 'subnodes' are used in a nested process
+            # This logic mimics graph_generator_utils but is adapted for the specific flow structure
+            # For a pure flowchart, often nodes are all the same color.
+            # If you want gradient for subprocesses, the current_depth logic needs to be more robust for different node types.
+            
+            # Let's use base_color directly for all main nodes and only apply gradient for 'subnodes'
+            # For now, we'll pass current_depth=0 to add_nodes_and_edges when called recursively
+            # to ensure the main flow nodes are consistent.
+
+            dot.node(
+                node_id,
+                node_info['label'],
+                shape=shape,
+                style='filled,rounded',
+                fillcolor=base_color, # Use the selected base color
+                fontcolor='white' if base_color == '#19191a' else 'black', # Adjust for readability
+                fontsize='14'
+            )
+
+        # Add connections (edges)
+        for connection in data.get('connections', []):
+            dot.edge(
+                connection['from'],
+                connection['to'],
+                label=connection.get('label', ''),
+                color='#4a4a4a', # Dark gray for lines
+                fontcolor='#4a4a4a',
+                fontsize='10'
+            )
+        
+        # If there's a start_node, ensure it's visually marked
+        if 'start_node' in data:
+            dot.node(data['start_node'], data['start_node'], shape=node_shapes['start'], style='filled,rounded', fillcolor='#2196F3', fontcolor='white', fontsize='14')
+        if 'end_node' in data and data['end_node'] in all_nodes:
+             dot.node(data['end_node'], all_nodes[data['end_node']]['label'], shape=node_shapes['end'], style='filled,rounded', fillcolor='#F44336', fontcolor='white', fontsize='14')
+
+
+        # Save to temporary file
+        with NamedTemporaryFile(delete=False, suffix='.png') as tmp:
+            dot.render(tmp.name, format='png', cleanup=True)
+            return tmp.name + '.png'
+
+    except json.JSONDecodeError:
+        return "Error: Invalid JSON format"
+    except Exception as e:
+        return f"Error: {str(e)}"
+