Mermaid Ruby

gem 'diagram' # The base gem for creating diagram objects
gem 'mermaid' # This gem, for generating Mermaid syntax

require 'diagrams'
require 'mermaid' # This applies the patches

# --- Example: State Diagram ---
state_a = Diagrams::Elements::State.new(id: 'A', label: 'State A')
state_b = Diagrams::Elements::State.new(id: 'B')
transition1 = Diagrams::Elements::Transition.new(source_state_id: '*', target_state_id: 'A')
transition2 = Diagrams::Elements::Transition.new(source_state_id: 'A', target_state_id: 'B', label: 'Event X')

state_diagram = Diagrams::StateDiagram.new(
  states: [state_a, state_b],
  transitions: [transition1, transition2]
)

puts state_diagram.to_mermaid
# Output:
# stateDiagram-v2
#   A : State A
#   [*] --> A
#   A --> B : Event X

# --- Example: Class Diagram ---
class_animal = Diagrams::Elements::ClassEntity.new(name: 'Animal', attributes: ['+String name'])
class_dog = Diagrams::Elements::ClassEntity.new(name: 'Dog', attributes: ['+String breed'], methods: ['+bark() void'])
rel_inheritance = Diagrams::Elements::Relationship.new(
  source_class_name: 'Dog',
  target_class_name: 'Animal',
  type: 'inheritance'
)

class_diagram = Diagrams::ClassDiagram.new(
  classes: [class_animal, class_dog],
  relationships: [rel_inheritance]
)

puts class_diagram.to_mermaid
# Output:
# classDiagram
# class Animal {
#   +String name
# }
# class Dog {
#   +String breed
#   +bark() void
# }
# Dog <|-- Animal

# --- Example: Flowchart ---
node1 = Diagrams::Elements::Node.new(id: 'n1', label: 'Start')
node2 = Diagrams::Elements::Node.new(id: 'n2', label: 'Process')
edge1 = Diagrams::Elements::Edge.new(source_id: 'n1', target_id: 'n2', label: 'Go')

flowchart = Diagrams::FlowchartDiagram.new(nodes: [node1, node2], edges: [edge1])

puts flowchart.to_mermaid
# Output:
# graph TD
#   n1["Start"]
#   n2["Process"]
#   n1 -- "Go" --> n2

# --- Example: Pie Chart ---
slice1 = Diagrams::Elements::Slice.new(label: 'Work', value: 8)
slice2 = Diagrams::Elements::Slice.new(label: 'Sleep', value: 8)
slice3 = Diagrams::Elements::Slice.new(label: 'Play', value: 8)

pie_chart = Diagrams::PieDiagram.new(title: 'Daily Routine', slices: [slice1, slice2, slice3])

puts pie_chart.to_mermaid
# Output:
# pie
# title Daily Routine
# "Work" : 8
# "Sleep" : 8
# "Play" : 8

# --- Example: Gantt Chart ---
gantt_chart = Diagrams::GanttDiagram.new(title: 'Project Timeline')
gantt_chart.add_task(id: 't1', label: 'Phase 1', start: '2024-01-01', duration: '10d')
gantt_chart.add_task(id: 't2', label: 'Phase 2', start: '2024-01-11', duration: '10d')

puts gantt_chart.to_mermaid
# Output:
# gantt
# title Project Timeline
# section Default Section
# Phase 1 :t1, 2024-01-01, 10d
# Phase 2 :t2, 2024-01-11, 10d