File size: 4,938 Bytes
7cd1bcd
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
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)}"