import { describe, expect, it, vi } from "vitest"

import { LGraph } from "@/litegraph"
import { SubgraphNode } from "@/subgraph/SubgraphNode"

// Note: Avoiding createMemoryLeakTest as it relies on non-deterministic GC behavior
import { subgraphTest } from "./fixtures/subgraphFixtures"
import {
  createEventCapture,
  createTestSubgraph,
  createTestSubgraphNode,
} from "./fixtures/subgraphHelpers"

// Mock WeakRef to detect if objects can be garbage collected
declare global {
  const gc: (() => void) | undefined
}

describe("SubgraphNode Memory Management", () => {
  describe("Event Listener Cleanup", () => {
    it("should register event listeners on construction", () => {
      const subgraph = createTestSubgraph()

      // Spy on addEventListener to track listener registration
      const addEventSpy = vi.spyOn(subgraph.events, "addEventListener")
      const initialCalls = addEventSpy.mock.calls.length

      createTestSubgraphNode(subgraph)

      // Should have registered listeners for subgraph events
      expect(addEventSpy.mock.calls.length).toBeGreaterThan(initialCalls)

      // Should have registered listeners for all major events
      const eventTypes = addEventSpy.mock.calls.map(call => call[0])
      expect(eventTypes).toContain("input-added")
      expect(eventTypes).toContain("removing-input")
      expect(eventTypes).toContain("output-added")
      expect(eventTypes).toContain("removing-output")
      expect(eventTypes).toContain("renaming-input")
      expect(eventTypes).toContain("renaming-output")
    })

    it("CRITICAL: should clean up input listeners on removal", () => {
      const subgraph = createTestSubgraph({
        inputs: [{ name: "input1", type: "number" }],
      })
      const subgraphNode = createTestSubgraphNode(subgraph)

      // Add input should have created listeners
      expect(subgraphNode.inputs[0]._listenerController).toBeDefined()
      expect(subgraphNode.inputs[0]._listenerController?.signal.aborted).toBe(false)

      // Call onRemoved to simulate node removal
      subgraphNode.onRemoved()

      // Input listeners should be aborted
      expect(subgraphNode.inputs[0]._listenerController?.signal.aborted).toBe(true)
    })

    it("CRITICAL: main subgraph event listeners are NOT cleaned up (MEMORY LEAK)", () => {
      const subgraph = createTestSubgraph()

      // Track listener registration
      const removeEventSpy = vi.spyOn(subgraph.events, "removeEventListener")
      const addEventSpy = vi.spyOn(subgraph.events, "addEventListener")
      const initialAddCalls = addEventSpy.mock.calls.length

      const subgraphNode = createTestSubgraphNode(subgraph)
      const addCallsAfterCreate = addEventSpy.mock.calls.length

      // Verify listeners were added
      expect(addCallsAfterCreate).toBeGreaterThan(initialAddCalls)

      // Call onRemoved
      subgraphNode.onRemoved()

      // CRITICAL BUG: Main subgraph event listeners are NOT removed
      // onRemoved only cleans up input-specific listeners, not the main ones
      expect(removeEventSpy).not.toHaveBeenCalled()

      // This proves the memory leak exists
      console.warn("MEMORY LEAK CONFIRMED: SubgraphNode event listeners not cleaned up on removal")
    })

    it("should not accumulate listeners during reconfiguration", () => {
      const subgraph = createTestSubgraph({
        inputs: [{ name: "input1", type: "number" }],
      })
      const subgraphNode = createTestSubgraphNode(subgraph)

      const addEventSpy = vi.spyOn(subgraph.events, "addEventListener")
      const initialCalls = addEventSpy.mock.calls.length

      // Reconfigure multiple times
      for (let i = 0; i < 5; i++) {
        subgraphNode.configure({
          id: subgraphNode.id,
          type: subgraph.id,
          pos: [100 * i, 100 * i],
          size: [200, 100],
          inputs: [],
          outputs: [],
          properties: {},
          flags: {},
          mode: 0,
        })
      }

      // Should not add new main subgraph listeners
      // (Only input-specific listeners might be reconfigured)
      const finalCalls = addEventSpy.mock.calls.length
      expect(finalCalls).toBe(initialCalls) // Main listeners not re-added
    })

    it("should demonstrate memory leak with multiple instances (limited scope)", () => {
      const subgraph = createTestSubgraph()

      // Track total listener count
      const addEventSpy = vi.spyOn(subgraph.events, "addEventListener")
      let totalListenersAdded = 0

      // Create and "remove" multiple instances (limited to 3 for test performance)
      const instances: SubgraphNode[] = []

      for (let i = 0; i < 3; i++) {
        const initialCalls = addEventSpy.mock.calls.length
        const instance = createTestSubgraphNode(subgraph, { id: i })
        instances.push(instance)

        const callsAfterCreate = addEventSpy.mock.calls.length
        totalListenersAdded += (callsAfterCreate - initialCalls)

        // Simulate removal (but listeners won't be cleaned up)
        instance.onRemoved()
      }

      // All listeners are still registered even though nodes are "removed"
      expect(totalListenersAdded).toBeGreaterThan(0)

      // Document the leak without excessive accumulation
      console.warn(`Memory leak demonstrated: ${totalListenersAdded} listeners accumulated from ${instances.length} instances`)

      // IMPORTANT: This test intentionally creates a small memory leak to demonstrate the bug.
      // In production, this would accumulate over time and cause performance issues.
      // The leak is limited to 3 instances to minimize test suite impact.
    })
  })

  describe("Memory Leak Prevention Tests", () => {
    it("verifies proper cleanup workflow exists", () => {
      // This test documents the expected cleanup workflow without relying on GC
      const subgraph = createTestSubgraph()
      const subgraphNode = createTestSubgraphNode(subgraph)

      // Track cleanup state
      const cleanupState = {
        inputListenersCleanedUp: false,
        mainListenersCleanedUp: false,
        widgetReferencesCleared: false,
      }

      // Check if input listeners exist and are set up
      const input = subgraphNode.inputs[0]

      // Call cleanup
      subgraphNode.onRemoved()

      // Verify what gets cleaned up
      if (input && "_listenerController" in input && (input as any)._listenerController) {
        cleanupState.inputListenersCleanedUp = (input as any)._listenerController.signal.aborted === true
        expect(cleanupState.inputListenersCleanedUp).toBe(true) // This works when input exists
      } else {
        // If no input or no listener controller, that's also valid
        cleanupState.inputListenersCleanedUp = true
        expect(cleanupState.inputListenersCleanedUp).toBe(true)
      }

      // TODO: These should be true after proper implementation
      // expect(cleanupState.mainListenersCleanedUp).toBe(true)
      // expect(cleanupState.widgetReferencesCleared).toBe(true)

      // This test serves as documentation for what needs to be implemented
    })

    it("should clean up widget references properly", () => {
      const subgraph = createTestSubgraph({
        inputs: [{ name: "input1", type: "number" }],
      })
      const subgraphNode = createTestSubgraphNode(subgraph)

      // Simulate widget promotion
      const input = subgraphNode.inputs[0]
      input._widget = {
        type: "number",
        name: "test_widget",
        value: 42,
        draw: vi.fn(),
        mouse: vi.fn(),
        computeSize: vi.fn(),
        createCopyForNode: vi.fn(),
      }

      input.widget = { name: "test_widget" }

      expect(input._widget).toBeDefined()
      expect(input.widget).toBeDefined()

      // Removal should clean up widget references
      subgraphNode.onRemoved()

      // Input-specific listeners are cleaned up, but widget refs may remain
      // This tests the current behavior
      expect(input._listenerController?.signal.aborted).toBe(true)
    })

    it("should handle rapid creation/destruction cycles", () => {
      const subgraph = createTestSubgraph()

      // Simulate rapid creation/destruction that might happen in UI
      const instances: SubgraphNode[] = []

      for (let cycle = 0; cycle < 10; cycle++) {
        // Create instance
        const instance = createTestSubgraphNode(subgraph, { id: cycle })
        instances.push(instance)

        // Add to graph
        const parentGraph = new LGraph()
        parentGraph.add(instance)

        // Remove from graph
        parentGraph.remove(instance)
        instance.onRemoved()
      }

      // All instances have been "removed" but event listeners remain
      // This demonstrates the accumulation problem
      expect(instances).toHaveLength(10)

      // Each instance still holds references through event listeners
      // In a real app, this would cause memory growth over time
    })
  })

  describe("Widget Promotion Memory Management", () => {
    it("should clean up promoted widget references", () => {
      const subgraph = createTestSubgraph({
        inputs: [{ name: "testInput", type: "number" }],
      })
      const subgraphNode = createTestSubgraphNode(subgraph)

      // Simulate widget promotion scenario
      const input = subgraphNode.inputs[0]
      const mockWidget = {
        type: "number",
        name: "promoted_widget",
        value: 123,
        draw: vi.fn(),
        mouse: vi.fn(),
        computeSize: vi.fn(),
        createCopyForNode: vi.fn().mockReturnValue({
          type: "number",
          name: "promoted_widget",
          value: 123,
        }),
      }

      // Simulate widget promotion
      input._widget = mockWidget
      input.widget = { name: "promoted_widget" }
      subgraphNode.widgets.push(mockWidget)

      expect(input._widget).toBe(mockWidget)
      expect(input.widget).toBeDefined()
      expect(subgraphNode.widgets).toContain(mockWidget)

      // Remove widget (this should clean up references)
      subgraphNode.removeWidget(mockWidget)

      // Widget should be removed from array
      expect(subgraphNode.widgets).not.toContain(mockWidget)

      // References should be cleaned up (testing current implementation)
      // Note: The PR #1107 fix should clean these up
    })

    it("should not leak widgets during reconfiguration", () => {
      const subgraph = createTestSubgraph({
        inputs: [{ name: "input1", type: "number" }],
      })
      const subgraphNode = createTestSubgraphNode(subgraph)

      // Track widget count before and after reconfigurations
      const initialWidgetCount = subgraphNode.widgets.length

      // Reconfigure multiple times
      for (let i = 0; i < 3; i++) {
        subgraphNode.configure({
          id: subgraphNode.id,
          type: subgraph.id,
          pos: [100, 100],
          size: [200, 100],
          inputs: [],
          outputs: [],
          properties: {},
          flags: {},
          mode: 0,
        })
      }

      // Widget count should not accumulate
      expect(subgraphNode.widgets.length).toBe(initialWidgetCount)
    })
  })

  describe("Memory Leak Documentation", () => {
    it("documents the known memory leak pattern", () => {
      // This test documents the exact memory leak pattern for future fixes

      const subgraph = createTestSubgraph()
      const eventCapture = createEventCapture(subgraph.events, [
        "input-added",
        "output-added",
        "removing-input",
        "removing-output",
        "renaming-input",
        "renaming-output",
      ])

      // Create SubgraphNode - this registers 6 event listeners
      const subgraphNode = createTestSubgraphNode(subgraph)

      // The memory leak occurs here:
      // 1. SubgraphNode constructor (lines 52-92) adds event listeners
      // 2. These create strong references: subgraph.events -> SubgraphNode
      // 3. onRemoved() method (lines 302-306) only cleans input listeners
      // 4. Main subgraph event listeners are NEVER removed

      expect(subgraphNode).toBeDefined()

      // Cleanup test resources
      eventCapture.cleanup()

      console.log("Memory leak pattern documented: SubgraphNode event listeners persist after removal")
    })

    it("provides solution blueprint for memory leak fix", () => {
      // This test shows what the fix should look like

      const subgraph = createTestSubgraph()

      // SOLUTION: SubgraphNode should use AbortController pattern
      //
      // In constructor:
      // this.eventAbortController = new AbortController()
      // const signal = this.eventAbortController.signal
      // subgraphEvents.addEventListener("input-added", handler, { signal })
      //
      // In onRemoved():
      // this.eventAbortController.abort() // Removes ALL listeners

      const subgraphNode = createTestSubgraphNode(subgraph)

      // Current implementation only cleans input listeners
      subgraphNode.onRemoved()

      // TODO: Implement AbortController pattern to fix memory leak
      expect(true).toBe(true) // Placeholder - documents intended solution
    })
  })
})

describe("Performance Impact of Memory Leak", () => {
  it("measures event handler overhead with multiple instances", () => {
    const subgraph = createTestSubgraph()

    // Create multiple instances (reduced from 50 to 20 for test efficiency)
    const instances: SubgraphNode[] = []
    const startTime = performance.now()

    for (let i = 0; i < 20; i++) {
      instances.push(createTestSubgraphNode(subgraph, { id: i }))
    }

    const creationTime = performance.now() - startTime

    // Trigger an event that will call ALL accumulated listeners
    const eventStartTime = performance.now()
    subgraph.addInput("performance_test", "number")
    const eventTime = performance.now() - eventStartTime

    console.log(`Created ${instances.length} instances in ${creationTime.toFixed(2)}ms`)
    console.log(`Event dispatch took ${eventTime.toFixed(2)}ms (${instances.length} listeners)`)

    // More instances = more event listeners = slower event handling
    // This demonstrates the performance impact of the memory leak
    expect(eventTime).toBeGreaterThan(0)
  })

  it("demonstrates listener accumulation impact", () => {
    // Test with different numbers of instances (reduced scale for efficiency)
    const testCases = [5, 10, 15]

    for (const instanceCount of testCases) {
      // Clean test - create fresh subgraph
      const testSubgraph = createTestSubgraph()

      // Create instances
      for (let i = 0; i < instanceCount; i++) {
        createTestSubgraphNode(testSubgraph, { id: i })
      }

      // Measure event dispatch time
      const startTime = performance.now()
      testSubgraph.addInput(`test_${instanceCount}`, "number")
      const dispatchTime = performance.now() - startTime

      console.log(`${instanceCount} instances: ${dispatchTime.toFixed(3)}ms event dispatch`)
    }

    // This test documents that more instances = more listeners = slower events
    expect(true).toBe(true)
  })
})

describe("SubgraphMemory - Event Listener Management", () => {
  subgraphTest("event handlers still work after node creation", ({ emptySubgraph }) => {
    const rootGraph = new LGraph()
    const subgraphNode = createTestSubgraphNode(emptySubgraph)
    rootGraph.add(subgraphNode)

    const handler = vi.fn()
    emptySubgraph.events.addEventListener("input-added", handler)

    emptySubgraph.addInput("test", "number")

    expect(handler).toHaveBeenCalledTimes(1)
    expect(handler).toHaveBeenCalledWith(expect.objectContaining({
      type: "input-added",
    }))
  })

  subgraphTest("can add and remove multiple nodes without errors", ({ emptySubgraph }) => {
    const rootGraph = new LGraph()
    const nodes: ReturnType<typeof createTestSubgraphNode>[] = []

    // Should be able to create multiple nodes without issues
    for (let i = 0; i < 5; i++) {
      const subgraphNode = createTestSubgraphNode(emptySubgraph)
      rootGraph.add(subgraphNode)
      nodes.push(subgraphNode)
    }

    expect(rootGraph.nodes.length).toBe(5)

    // Should be able to remove them all without issues
    for (const node of nodes) {
      rootGraph.remove(node)
    }

    expect(rootGraph.nodes.length).toBe(0)
  })

  subgraphTest("supports AbortController cleanup patterns", ({ emptySubgraph }) => {
    const abortController = new AbortController()
    const { signal } = abortController

    const handler = vi.fn()

    emptySubgraph.events.addEventListener("input-added", handler, { signal })

    emptySubgraph.addInput("test1", "number")
    expect(handler).toHaveBeenCalledTimes(1)

    abortController.abort()

    emptySubgraph.addInput("test2", "number")
    expect(handler).toHaveBeenCalledTimes(1)
  })

  subgraphTest("handles multiple creation/deletion cycles", ({ emptySubgraph }) => {
    const rootGraph = new LGraph()

    for (let cycle = 0; cycle < 3; cycle++) {
      const nodes = []

      for (let i = 0; i < 5; i++) {
        const subgraphNode = createTestSubgraphNode(emptySubgraph)
        rootGraph.add(subgraphNode)
        nodes.push(subgraphNode)
      }

      expect(rootGraph.nodes.length).toBe(5)

      for (const node of nodes) {
        rootGraph.remove(node)
      }

      expect(rootGraph.nodes.length).toBe(0)
    }
  })
})

describe("SubgraphMemory - Reference Management", () => {
  it("properly manages subgraph references in root graph", () => {
    const rootGraph = new LGraph()
    const subgraph = createTestSubgraph()
    const subgraphId = subgraph.id

    // Add subgraph to root graph registry
    rootGraph.subgraphs.set(subgraphId, subgraph)
    expect(rootGraph.subgraphs.has(subgraphId)).toBe(true)
    expect(rootGraph.subgraphs.get(subgraphId)).toBe(subgraph)

    // Remove subgraph from registry
    rootGraph.subgraphs.delete(subgraphId)
    expect(rootGraph.subgraphs.has(subgraphId)).toBe(false)
  })

  it("maintains proper parent-child references", () => {
    const rootGraph = new LGraph()
    const subgraph = createTestSubgraph({ nodeCount: 2 })
    const subgraphNode = createTestSubgraphNode(subgraph)

    // Before adding to graph, node might already have a graph reference
    // (This depends on how createTestSubgraphNode works)

    // Add to graph
    rootGraph.add(subgraphNode)
    expect(subgraphNode.graph).toBe(rootGraph)
    expect(rootGraph.nodes).toContain(subgraphNode)

    // Remove from graph
    rootGraph.remove(subgraphNode)
    expect(rootGraph.nodes).not.toContain(subgraphNode)

    // After removal, graph reference behavior may vary by implementation
    // The important thing is that it's removed from the graph's nodes array
  })

  it("prevents circular reference creation", () => {
    const subgraph = createTestSubgraph({ nodeCount: 1 })
    const subgraphNode = createTestSubgraphNode(subgraph)

    // Subgraph should not contain its own instance node
    expect(subgraph.nodes).not.toContain(subgraphNode)

    // If circular references were attempted, they should be detected
    // (This documents the expected behavior - implementation may vary)
    expect(subgraphNode.subgraph).toBe(subgraph)
    expect(subgraph.nodes.includes(subgraphNode)).toBe(false)
  })
})

describe("SubgraphMemory - Widget Reference Management", () => {
  subgraphTest("properly sets and clears widget references", ({ simpleSubgraph }) => {
    const subgraphNode = createTestSubgraphNode(simpleSubgraph)
    const input = subgraphNode.inputs[0]

    // Mock widget for testing
    const mockWidget = {
      type: "number",
      value: 42,
      name: "test_widget",
    }

    // Set widget reference
    if (input && "_widget" in input) {
      ;(input as any)._widget = mockWidget
      expect((input as any)._widget).toBe(mockWidget)
    }

    // Clear widget reference
    if (input && "_widget" in input) {
      ;(input as any)._widget = undefined
      expect((input as any)._widget).toBeUndefined()
    }
  })

  subgraphTest("maintains widget count consistency", ({ simpleSubgraph }) => {
    const subgraphNode = createTestSubgraphNode(simpleSubgraph)

    const initialWidgetCount = subgraphNode.widgets?.length || 0

    // Add mock widgets
    const widget1 = { type: "number", value: 1, name: "widget1" }
    const widget2 = { type: "string", value: "test", name: "widget2" }

    if (subgraphNode.widgets) {
      subgraphNode.widgets.push(widget1, widget2)
      expect(subgraphNode.widgets.length).toBe(initialWidgetCount + 2)
    }

    // Remove widgets
    if (subgraphNode.widgets) {
      subgraphNode.widgets.length = initialWidgetCount
      expect(subgraphNode.widgets.length).toBe(initialWidgetCount)
    }
  })

  subgraphTest("cleans up references during node removal", ({ simpleSubgraph }) => {
    const subgraphNode = createTestSubgraphNode(simpleSubgraph)
    const input = subgraphNode.inputs[0]
    const output = subgraphNode.outputs[0]

    // Set up references that should be cleaned up
    const mockReferences = {
      widget: { type: "number", value: 42 },
      connection: { id: 1, type: "number" },
      listener: vi.fn(),
    }

    // Set references
    if (input) {
      ;(input as any)._widget = mockReferences.widget
      ;(input as any)._connection = mockReferences.connection
    }
    if (output) {
      ;(input as any)._connection = mockReferences.connection
    }

    // Verify references are set
    expect((input as any)?._widget).toBe(mockReferences.widget)
    expect((input as any)?._connection).toBe(mockReferences.connection)

    // Simulate proper cleanup (what onRemoved should do)
    subgraphNode.onRemoved()

    // Input-specific listeners should be cleaned up (this works)
    if (input && "_listenerController" in input) {
      expect((input as any)._listenerController?.signal.aborted).toBe(true)
    }

    // Note: Other references may still exist - this documents current behavior
    // In a proper implementation, onRemoved should clean these up too
  })
})

describe("SubgraphMemory - Performance and Scale", () => {
  subgraphTest("handles multiple subgraphs in same graph", ({ subgraphWithNode }) => {
    const { parentGraph } = subgraphWithNode
    const subgraphA = createTestSubgraph({ name: "Subgraph A" })
    const subgraphB = createTestSubgraph({ name: "Subgraph B" })

    const nodeA = createTestSubgraphNode(subgraphA)
    const nodeB = createTestSubgraphNode(subgraphB)

    parentGraph.add(nodeA)
    parentGraph.add(nodeB)

    expect(nodeA.graph).toBe(parentGraph)
    expect(nodeB.graph).toBe(parentGraph)
    expect(parentGraph.nodes.length).toBe(3) // Original + nodeA + nodeB

    parentGraph.remove(nodeA)
    parentGraph.remove(nodeB)

    expect(parentGraph.nodes.length).toBe(1) // Only the original subgraphNode remains
  })

  it("handles many instances without issues", () => {
    const subgraph = createTestSubgraph({
      inputs: [{ name: "stress_input", type: "number" }],
      outputs: [{ name: "stress_output", type: "number" }],
    })

    const rootGraph = new LGraph()
    const instances = []

    // Create instances (reduced from 50 to 25 for test efficiency)
    for (let i = 0; i < 25; i++) {
      const instance = createTestSubgraphNode(subgraph)
      rootGraph.add(instance)
      instances.push(instance)
    }

    expect(instances.length).toBe(25)
    expect(rootGraph.nodes.length).toBe(25)

    // Remove all instances (proper cleanup)
    for (const instance of instances) {
      rootGraph.remove(instance)
    }

    expect(rootGraph.nodes.length).toBe(0)
  })

  it("maintains consistent behavior across multiple cycles", () => {
    const subgraph = createTestSubgraph()
    const rootGraph = new LGraph()

    for (let cycle = 0; cycle < 10; cycle++) {
      const instances = []

      // Create instances
      for (let i = 0; i < 10; i++) {
        const instance = createTestSubgraphNode(subgraph)
        rootGraph.add(instance)
        instances.push(instance)
      }

      expect(rootGraph.nodes.length).toBe(10)

      // Remove instances
      for (const instance of instances) {
        rootGraph.remove(instance)
      }

      expect(rootGraph.nodes.length).toBe(0)
    }
  })
})