import { describe, it, expect } from 'vitest'
import type { RendererType, LGraphExtra } from '../src/lib/litegraph/src/LGraph'

/**
 * Tests for the RendererType (formerly rendererType) type definition
 * 
 * This tests the type rename from 'rendererType' to 'RendererType' to follow
 * TypeScript naming conventions where types should use PascalCase.
 */
describe('RendererType', () => {
  describe('type definition', () => {
    it('should accept "LG" as a valid value', () => {
      const renderer: RendererType = 'LG'
      expect(renderer).toBe('LG')
    })

    it('should accept "Vue" as a valid value', () => {
      const renderer: RendererType = 'Vue'
      expect(renderer).toBe('Vue')
    })

    it('should be assignable to LGraphExtra workflowRendererVersion property', () => {
      const extra: LGraphExtra = {
        workflowRendererVersion: 'LG'
      }
      expect(extra.workflowRendererVersion).toBe('LG')

      extra.workflowRendererVersion = 'Vue'
      expect(extra.workflowRendererVersion).toBe('Vue')
    })

    it('should allow undefined for workflowRendererVersion', () => {
      const extra: LGraphExtra = {
        workflowRendererVersion: undefined
      }
      expect(extra.workflowRendererVersion).toBeUndefined()
    })

    it('should work with optional chaining', () => {
      const extra: LGraphExtra = {}
      const version = extra.workflowRendererVersion
      expect(version).toBeUndefined()
    })
  })

  describe('type safety', () => {
    it('should prevent assignment of invalid string values at compile time', () => {
      // This test validates TypeScript compiler behavior
      // The following would cause a compile error:
      // const invalid: RendererType = 'Invalid'
      
      // We can test runtime validation if needed
      const validValues: RendererType[] = ['LG', 'Vue']
      validValues.forEach((value) => {
        expect(['LG', 'Vue']).toContain(value)
      })
    })

    it('should work with type guards', () => {
      const isValidRendererType = (value: string): value is RendererType => {
        return value === 'LG' || value === 'Vue'
      }

      expect(isValidRendererType('LG')).toBe(true)
      expect(isValidRendererType('Vue')).toBe(true)
      expect(isValidRendererType('Invalid')).toBe(false)
    })

    it('should work in switch statements', () => {
      const testSwitch = (renderer: RendererType): string => {
        switch (renderer) {
          case 'LG':
            return 'Legacy LiteGraph'
          case 'Vue':
            return 'Vue Renderer'
          default:
            // TypeScript should ensure this is unreachable
            const _exhaustive: never = renderer
            return _exhaustive
        }
      }

      expect(testSwitch('LG')).toBe('Legacy LiteGraph')
      expect(testSwitch('Vue')).toBe('Vue Renderer')
    })
  })

  describe('usage in graph serialization', () => {
    it('should serialize and deserialize RendererType correctly', () => {
      const extra: LGraphExtra = {
        workflowRendererVersion: 'Vue'
      }

      const serialized = JSON.stringify(extra)
      const deserialized: LGraphExtra = JSON.parse(serialized)

      expect(deserialized.workflowRendererVersion).toBe('Vue')
    })

    it('should handle missing workflowRendererVersion in deserialization', () => {
      const json = '{}'
      const extra: LGraphExtra = JSON.parse(json)

      expect(extra.workflowRendererVersion).toBeUndefined()
    })

    it('should handle null workflowRendererVersion', () => {
      const extra: LGraphExtra = {
        workflowRendererVersion: undefined
      }

      expect(extra.workflowRendererVersion).toBeUndefined()
    })
  })

  describe('backward compatibility considerations', () => {
    it('should work with both old and new renderer formats', () => {
      // Even though the type is renamed, the values remain the same
      const lgRenderer: RendererType = 'LG'
      const vueRenderer: RendererType = 'Vue'

      expect(lgRenderer).toBe('LG')
      expect(vueRenderer).toBe('Vue')
    })

    it('should support migration scenarios', () => {
      // Simulating reading from an old format
      const oldFormat = { workflowRendererVersion: 'LG' as RendererType }
      
      // Converting to new format (type is already compatible)
      const newFormat: LGraphExtra = {
        workflowRendererVersion: oldFormat.workflowRendererVersion
      }

      expect(newFormat.workflowRendererVersion).toBe('LG')
    })
  })

  describe('default values and initialization', () => {
    it('should handle default initialization', () => {
      const extra: LGraphExtra = {}
      
      // workflowRendererVersion should be undefined by default
      expect(extra.workflowRendererVersion).toBeUndefined()
    })

    it('should support nullish coalescing', () => {
      const extra: LGraphExtra = {}
      const renderer = extra.workflowRendererVersion ?? 'LG'
      
      expect(renderer).toBe('LG')
    })

    it('should support optional chaining with default', () => {
      let extra: LGraphExtra | undefined = undefined
      const renderer = extra?.workflowRendererVersion ?? 'LG'
      
      expect(renderer).toBe('LG')
    })
  })
})