import { describe, test, expect, beforeEach } from '@jest/globals';
import { RhizomeNode, Lossless, createDelta } from "../../../../src";
import { CollapsedDelta } from "../../../../src/views/lossless";
import { 
  CustomResolver, 
  ResolverPlugin,
  type DependencyStates
} from "../../../../src/views/resolvers/custom-resolvers";
import type { LosslessViewOne } from '@src/views/resolvers/lossless-view';

type PropertyTypes = 'string' | 'number' | 'boolean' | 'object' | 'array';
import { 
  LastWriteWinsPlugin, 
  FirstWriteWinsPlugin, 
  ConcatenationPlugin, 
  MajorityVotePlugin, 
  MinPlugin, 
  MaxPlugin 
} from "../../../../src/views/resolvers/custom-resolvers";

type PropertyTypes = string | number | boolean | null;

describe('Custom Resolvers', () => {
  let node: RhizomeNode;
  let lossless: Lossless;

  beforeEach(() => {
    node = new RhizomeNode();
    lossless = new Lossless(node);
  });

  describe('Built-in Plugins', () => {
    test('LastWriteWinsPlugin should resolve to most recent value', () => {
      // First delta with earlier timestamp
      lossless.ingestDelta(
        createDelta('user1', 'host1')
          .withTimestamp(1000)
          .setProperty('entity1', 'name', 'first', 'collection')
          .buildV1()
      );

      // Second delta with later timestamp (should win)
      lossless.ingestDelta(
        createDelta('user1', 'host1')
          .withTimestamp(2000)
          .setProperty('entity1', 'name', 'second', 'collection')
          .buildV1()
      );

      const resolver = new CustomResolver(lossless, {
        name: new LastWriteWinsPlugin()
      });

      const result = resolver.resolve();
      expect(result).toBeDefined();
      expect(result!['entity1'].properties.name).toBe('second');
    });

    test('FirstWriteWinsPlugin should resolve to earliest value', () => {
      // Later delta (should be ignored by FirstWriteWins)
      lossless.ingestDelta(
        createDelta('user1', 'host1')
          .withTimestamp(2000)
          .setProperty('entity1', 'name', 'second', 'collection')
          .buildV1()
      );

      // Earlier delta (should win with FirstWriteWins)
      lossless.ingestDelta(
        createDelta('user1', 'host1')
          .withTimestamp(1000)
          .setProperty('entity1', 'name', 'first', 'collection')
          .buildV1()
      );

      const resolver = new CustomResolver(lossless, {
        name: new FirstWriteWinsPlugin()
      });

      const result = resolver.resolve();
      expect(result).toBeDefined();
      expect(result!['entity1'].properties.name).toBe('first');
    });

    test('ConcatenationPlugin should join string values chronologically', () => {
      // First tag
      lossless.ingestDelta(
        createDelta('user1', 'host1')
          .withTimestamp(1000)
          .setProperty('entity1', 'tags', 'red', 'collection')
          .buildV1()
      );

      // Second tag (with later timestamp)
      lossless.ingestDelta(
        createDelta('user1', 'host1')
          .withTimestamp(3000)
          .setProperty('entity1', 'tags', 'blue', 'collection')
          .buildV1()
      );

      // Third tag (with timestamp between first and second)
      lossless.ingestDelta(
        createDelta('user1', 'host1')
          .withTimestamp(2000)
          .setProperty('entity1', 'tags', 'green', 'collection')
          .buildV1()
      );

      const resolver = new CustomResolver(lossless, {
        tags: new ConcatenationPlugin(' ')
      });

      const result = resolver.resolve();
      expect(result).toBeDefined();
      expect(result!['entity1'].properties.tags).toBe('red green blue');
    });

    test('ConcatenationPlugin should handle duplicates', () => {
      // First tag
      lossless.ingestDelta(
        createDelta('user1', 'host1')
          .withTimestamp(1000)
          .setProperty('entity1', 'tags', 'red', 'collection')
          .buildV1()
      );

      // Duplicate tag with later timestamp
      lossless.ingestDelta(
        createDelta('user1', 'host1')
          .withTimestamp(2000)
          .setProperty('entity1', 'tags', 'red', 'collection') // duplicate
          .buildV1()
      );

      const resolver = new CustomResolver(lossless, {
        tags: new ConcatenationPlugin(',')
      });

      const result = resolver.resolve();
      expect(result).toBeDefined();
      expect(result!['entity1'].properties.tags).toBe('red'); // Should not duplicate
    });

    test('MajorityVotePlugin should resolve to most voted value', () => {
      // Add 3 votes for 'red'
      lossless.ingestDelta(
        createDelta('user1', 'host1')
          .withTimestamp(1000)
          .setProperty('entity1', 'color', 'red', 'collection')
          .buildV1()
      );

      lossless.ingestDelta(
        createDelta('user2', 'host1')
          .withTimestamp(1000)
          .setProperty('entity1', 'color', 'red', 'collection')
          .buildV1()
      );

      lossless.ingestDelta(
        createDelta('user3', 'host1')
          .withTimestamp(1000)
          .setProperty('entity1', 'color', 'red', 'collection')
          .buildV1()
      );

      // Add 2 votes for 'blue'
      lossless.ingestDelta(
        createDelta('user4', 'host1')
          .withTimestamp(1000)
          .setProperty('entity1', 'color', 'blue', 'collection')
          .buildV1()
      );

      lossless.ingestDelta(
        createDelta('user5', 'host1')
          .withTimestamp(1000)
          .setProperty('entity1', 'color', 'blue', 'collection')
          .buildV1()
      );

      const resolver = new CustomResolver(lossless, {
        color: new MajorityVotePlugin()
      });

      const result = resolver.resolve();
      expect(result).toBeDefined();
      expect(result!['entity1'].properties.color).toBe('red'); // 3 votes vs 2 votes
    });

    test('MinPlugin should resolve to minimum numeric value', () => {
      // First score (100)
      lossless.ingestDelta(
        createDelta('user1', 'host1')
          .withTimestamp(1000)
          .setProperty('entity1', 'score', 100, 'collection')
          .buildV1()
      );

      // Second score (50) - this is the minimum
      lossless.ingestDelta(
        createDelta('user1', 'host1')
          .withTimestamp(2000)
          .setProperty('entity1', 'score', 50, 'collection')
          .buildV1()
      );

      // Third score (75)
      lossless.ingestDelta(
        createDelta('user1', 'host1')
          .withTimestamp(3000)
          .setProperty('entity1', 'score', 75, 'collection')
          .buildV1()
      );

      const resolver = new CustomResolver(lossless, {
        score: new MinPlugin()
      });

      const result = resolver.resolve();
      expect(result).toBeDefined();
      expect(result!['entity1'].properties.score).toBe(50);
    });

    test('MaxPlugin should resolve to maximum numeric value', () => {
      // First score (100)
      lossless.ingestDelta(
        createDelta('user1', 'host1')
          .withTimestamp(1000)
          .setProperty('entity1', 'score', 100, 'collection')
          .buildV1()
      );

      // Second score (150) - this is the maximum
      lossless.ingestDelta(
        createDelta('user1', 'host1')
          .withTimestamp(2000)
          .setProperty('entity1', 'score', 150, 'collection')
          .buildV1()
      );

      // Third score (75)
      lossless.ingestDelta(
        createDelta('user1', 'host1')
          .withTimestamp(3000)
          .setProperty('entity1', 'score', 75, 'collection')
          .buildV1()
      );

      const resolver = new CustomResolver(lossless, {
        score: new MaxPlugin()
      });

      const result = resolver.resolve();
      expect(result).toBeDefined();
      expect(result!['entity1'].properties.score).toBe(150);
    });
  });

  describe('Mixed Plugin Configurations', () => {
    test('should handle different plugins for different properties', () => {
      // Add name with different timestamps
      lossless.ingestDelta(
        createDelta('user1', 'host1')
          .withTimestamp(1000)
          .setProperty('entity1', 'name', 'old_name', 'collection')
          .buildV1()
      );

      // Update name with newer timestamp
      lossless.ingestDelta(
        createDelta('user1', 'host1')
          .withTimestamp(2000)
          .setProperty('entity1', 'name', 'new_name', 'collection')
          .buildV1()
      );

      // Add scores
      lossless.ingestDelta(
        createDelta('user1', 'host1')
          .withTimestamp(1000)
          .setProperty('entity1', 'score', 100, 'collection')
          .buildV1()
      );

      // Add another score (MinPlugin will pick the smaller one)
      lossless.ingestDelta(
        createDelta('user1', 'host1')
          .withTimestamp(2000)
          .setProperty('entity1', 'score', 50, 'collection')
          .buildV1()
      );

      const resolver = new CustomResolver(lossless, {
        name: new LastWriteWinsPlugin(), // Should resolve to 'new_name'
        score: new MinPlugin() // Should resolve to 50
      });

      const result = resolver.resolve();
      expect(result).toBeDefined();
      expect(result!['entity1'].properties.name).toBe('new_name');
      expect(result!['entity1'].properties.score).toBe(50);
    });

    test('should only include entities with configured properties', () => {
      // Entity1 has configured property
      lossless.ingestDelta(
        createDelta('user1', 'host1')
          .withTimestamp(1000)
          .setProperty('entity1', 'name', 'test', 'collection')
          .buildV1()
      );

      // Entity2 has non-configured property
      lossless.ingestDelta(
        createDelta('user1', 'host1')
          .withTimestamp(1000)
          .setProperty('entity2', 'other_prop', 'value', 'collection')
          .buildV1()
      );

      const resolver = new CustomResolver(lossless, {
        name: new LastWriteWinsPlugin()
      });

      const result = resolver.resolve();
      expect(result).toBeDefined();
      expect(result!['entity1']).toBeDefined();
      expect(result!['entity1'].properties.name).toBe('test');
      expect(result!['entity2']).toBeUndefined(); // No configured properties
    });
  });

  describe('Plugin Dependencies', () => {
    test('should detect circular dependencies', () => {
      // Define state interfaces
      interface PluginAState {
        value: string;
      }

      interface PluginBState {
        value: string;
      }

      // PluginA depends on PluginB
      class PluginA implements ResolverPlugin<PluginAState, 'b'> {
        readonly name = 'a' as const;
        readonly dependencies = ['b'] as const;
        
        initialize(): PluginAState {
          return { value: 'a' };
        }
        
        update(
          currentState: PluginAState,
          _newValue: unknown,
          _delta: CollapsedDelta,
          _dependencies: { b: { value: string } } = { b: { value: '' } }
        ): PluginAState {
          return { ...currentState };
        }
        
        resolve(
          _state: PluginAState,
          _dependencies: { b: { value: string } } = { b: { value: '' } }
        ): string {
          return 'a';
        }
      }

      // PluginB depends on PluginA
      interface PluginBState {
        value: string;
      }

      class PluginB implements ResolverPlugin<PluginBState, 'a'> {
        readonly name = 'b' as const;
        readonly dependencies = ['a'] as const;
        
        initialize(): PluginBState {
          return { value: 'b' };
        }
        
        update(
          currentState: PluginBState,
          _newValue: unknown,
          _delta: CollapsedDelta,
          _dependencies: { a: unknown } = { a: undefined }
        ): PluginBState {
          return currentState;
        }
        
        resolve(
          _state: PluginBState,
          _dependencies: { a: unknown } = { a: undefined }
        ): string {
          return 'b';
        }
      }

      expect(() => {
        new CustomResolver(lossless, {
          'a': new PluginA(),
          'b': new PluginB()
        });
      }).toThrow('Circular dependency detected');
    });

    describe('CustomResolver with plugin dependencies', () => {
    let lossless: LosslessViewOne;
    
    // Track plugin execution order
    const executionOrder: string[] = [];
    
    // Track plugin state updates and resolutions
    const pluginTracker = {
      first: { updated: false, resolved: false },
      second: { updated: false, resolved: false }
    };

    // Define plugin state interface
    interface PluginState {
      value: string;
      updated: boolean;
      resolved: boolean;
    }

      class FirstPlugin implements ResolverPlugin<PluginState, never> {
        readonly name = 'first' as const;
        readonly dependencies = [] as const;
        
        initialize(): PluginState {
          console.log('First plugin initialized');
          executionOrder.push('first-init');
          return { value: '', updated: false, resolved: false };
        }
        
        update(
          currentState: PluginState, 
          newValue: PropertyTypes, 
          _delta: CollapsedDelta, 
          _dependencies: Record<string, never> = {}
        ): PluginState {
          console.log('First plugin updated with value:', newValue);
          executionOrder.push('first-update');
          pluginTracker.first.updated = true;
          return { 
            ...currentState,
            value: String(newValue), 
            updated: true
          };
        }
        
        resolve(state: PluginState): string {
          console.log('First plugin resolved with value:', state.value);
          executionOrder.push('first-resolve');
          pluginTracker.first.resolved = true;
          return state.value;
        }
      }

      class SecondPlugin implements ResolverPlugin<PluginState, 'first'> {
        readonly name = 'second' as const;
        readonly dependencies = ['first'] as const;
        
        initialize(): PluginState {
          console.log('Second plugin initialized');
          executionOrder.push('second-init');
          return { value: '', updated: false, resolved: false };
        }
        
        update(
          currentState: PluginState, 
          newValue: PropertyTypes, 
          _delta: CollapsedDelta, 
          dependencies: { first: unknown }
        ): PluginState {
          console.log('Second plugin updated with value:', newValue);
          executionOrder.push('second-update');
          pluginTracker.second.updated = true;
          
          // Access the first plugin's resolved state
          const firstState = dependencies.first as PluginState;
          if (firstState) {
            executionOrder.push('second-has-first-state');
            console.log('Second plugin has access to first plugin state:', firstState);
          }
          
          return { 
            ...currentState,
            value: `${newValue}-${firstState?.value || 'unknown'}`,
            updated: true
          };
        }
        
        resolve(state: PluginState): string {
          console.log('Second plugin resolved with value:', state.value);
          executionOrder.push('second-resolve');
          pluginTracker.second.resolved = true;
          return state.value;
        }
      }

      // Create resolver with dependency order: first -> second
      console.log('Creating resolver with plugins');
      
      // Create test plugins
      const firstPlugin = new FirstPlugin();
      const secondPlugin = new SecondPlugin();
      
      // Create resolver with test plugins
      const testResolver = new CustomResolver({
        first: firstPlugin,
        second: secondPlugin
      });
      // Verify the execution order array is empty before processing
      expect(executionOrder).not.toContain('first-init');
      expect(executionOrder).not.toContain('second-init');
      expect(executionOrder).toHaveLength(0);
      
      // Create and ingest test data
      const delta = createDelta('test1', 'host1')
        .withTimestamp(1000)
        .setProperty('test1', 'first', 'first', 'prop1')
        .setProperty('test1', 'second', 'second', 'prop2')
        .buildV1();
        
      lossless.ingestDelta(delta);
  
      // Resolve the view
      const result = testResolver.resolve();
  
      // Verify the result
      expect(result).toBeDefined();
      if (!result) return;
      
      const testEntity = result['test1'];
      expect(testEntity).toBeDefined();
      if (!testEntity) return;
      
      // Check if properties exist
      expect(testEntity.properties).toBeDefined();
      
      // Check if plugins were resolved
      expect(pluginTracker.first.resolved).toBe(true);
      expect(pluginTracker.second.resolved).toBe(true);
      
      // Check if second plugin has access to first plugin's state
      expect(executionOrder).toContain('second-has-first-state');
      
      // Check if first plugin was processed before second
      const firstUpdateIndex = executionOrder.indexOf('first-update');
      const secondUpdateIndex = executionOrder.indexOf('second-update');
      expect(firstUpdateIndex).not.toBe(-1);
      expect(secondUpdateIndex).not.toBe(-1);
      expect(firstUpdateIndex).toBeLessThan(secondUpdateIndex);
      
      // Verify initialization order (first should be initialized before second)
      const firstInitIndex = executionOrder.indexOf('first-init');
      const secondInitIndex = executionOrder.indexOf('second-init');
      expect(firstInitIndex).not.toBe(-1);
      expect(secondInitIndex).not.toBe(-1);
      expect(firstInitIndex).toBeLessThan(secondInitIndex);
      
      // Check if resolve was called in the right order
      const firstResolveIndex = executionOrder.indexOf('first-resolve');
      const secondResolveIndex = executionOrder.indexOf('second-resolve');
      expect(firstResolveIndex).not.toBe(-1);
      expect(secondResolveIndex).not.toBe(-1);
      expect(firstResolveIndex).toBeLessThan(secondResolveIndex);
      expect(firstInitIndex).toBeLessThan(secondInitIndex);
      
      // Verify update order (first should be updated before second)
      expect(firstUpdateIndex).toBeGreaterThanOrEqual(0);
      expect(secondUpdateIndex).toBeGreaterThanOrEqual(0);
      expect(firstUpdateIndex).toBeLessThan(secondUpdateIndex);
      
      // Verify resolve order (first should be resolved before second)
      expect(firstResolveIndex).toBeGreaterThanOrEqual(0);
      expect(secondResolveIndex).toBeGreaterThanOrEqual(0);
      expect(firstResolveIndex).toBeLessThan(secondResolveIndex);
      
      // Check if second plugin could access first plugin's state
      expect(executionOrder).toContain('second-has-first-state');
      
      // Check resolved values if they exist
      if (testEntity.properties.first) {
        expect(testEntity.properties.first).toBe('first');
      }
      
      if (testEntity.properties.second) {
        // Second plugin's value is 'second-<first plugin's value>'
        expect(testEntity.properties.second).toBe('second-first');
      }
    });

    test('should allow plugins to depend on other plugin states', () => {
      // A plugin that applies a discount to a price
      class DiscountedPricePlugin implements ResolverPlugin<{ price: number }> {
        name = 'discounted-price';
        dependencies = ['discount'];
        
        initialize() {
          return { price: 0 };
        }
        
        update(
          currentState: { price: number }, 
          newValue: PropertyTypes, 
          _delta: CollapsedDelta,
          _allStates?: Record<string, unknown>
        ) {
          if (typeof newValue === 'number') {
            return { price: newValue };
          }
          return currentState;
        }
        
        resolve(
          state: { price: number },
          allStates?: Record<string, unknown>
        ): number | undefined {
          // Get discount from another plugin's state
          const discountState = allStates?.['discount'] as { value: number } | undefined;
          if (discountState) {
            return state.price * (1 - (discountState.value / 100));
          }
          return state.price;
        }
      }

      // A simple discount plugin
      class DiscountPlugin implements ResolverPlugin<{ value: number }> {
        name = 'discount';
        
        initialize() {
          return { value: 0 };
        }
        
        update(
          currentState: { value: number }, 
          newValue: PropertyTypes,
          _delta: CollapsedDelta,
          _allStates?: Record<string, unknown>
        ) {
          if (typeof newValue === 'number') {
            return { value: newValue };
          }
          return currentState;
        }
        
        resolve(
          state: { value: number },
          _allStates?: Record<string, unknown>
        ): number {
          return state.value;
        }
      }

      // Set base price
      lossless.ingestDelta(
        createDelta('user1', 'host1')
          .withTimestamp(1000)
          .setProperty('product1', 'price', 100, 'products')
          .buildV1()
      );

      // Set discount (20%)
      lossless.ingestDelta(
        createDelta('user1', 'host1')
          .withTimestamp(1000)
          .setProperty('product1', 'discount', 20, 'products')
          .buildV1()
      );

      const resolver = new CustomResolver(lossless, {
        price: new DiscountedPricePlugin(),
        discount: new DiscountPlugin()
      });

      const result = resolver.resolve();
      expect(result).toBeDefined();
      expect(result!['product1'].properties.price).toBe(80); // 100 - 20%
      expect(result!['product1'].properties.discount).toBe(20);
    });
  });

  describe('Custom Plugin Implementation', () => {
    test('should work with custom plugin', () => {
      // Custom plugin that counts the number of updates
      class CountPlugin implements ResolverPlugin<{count: number}> {
        name = 'count';

        initialize() {
          return {count: 0};
        }

        update(currentState: {count: number}, _newValue: PropertyTypes, _delta: CollapsedDelta) {
          return {count: currentState.count + 1};
        }

        resolve(state: {count: number}): PropertyTypes {
          return state.count;
        }
      }

      // First update
      lossless.ingestDelta(
        createDelta('user1', 'host1')
          .withTimestamp(1000)
          .setProperty('entity1', 'updates', 'first', 'collection')
          .buildV1()
      );

      // Second update
      lossless.ingestDelta(
        createDelta('user1', 'host1')
          .withTimestamp(2000)
          .setProperty('entity1', 'updates', 'second', 'collection')
          .buildV1()
      );

      // Third update
      lossless.ingestDelta(
        createDelta('user1', 'host1')
          .withTimestamp(3000)
          .setProperty('entity1', 'updates', 'third', 'collection')
          .buildV1()
      );

      const resolver = new CustomResolver(lossless, {
        updates: new CountPlugin()
      });

      const result = resolver.resolve();
      expect(result).toBeDefined();
      expect(result!['entity1'].properties.updates).toBe(3);
    });

    test('should work with stateful custom plugin', () => {
      // Custom plugin that calculates running average
      class RunningAveragePlugin implements ResolverPlugin<{sum: number, count: number}> {
        name = 'running-average';

        initialize() {
          return {sum: 0, count: 0};
        }

        update(currentState: {sum: number, count: number}, newValue: PropertyTypes, _delta: CollapsedDelta) {
          if (typeof newValue === 'number') {
            return {
              sum: currentState.sum + newValue,
              count: currentState.count + 1
            };
          }
          return currentState;
        }

        resolve(state: {sum: number, count: number}): PropertyTypes {
          return state.count > 0 ? state.sum / state.count : 0;
        }
      }

      // First score (10)
      lossless.ingestDelta(
        createDelta('user1', 'host1')
          .withTimestamp(1000)
          .setProperty('entity1', 'score', 10, 'collection')
          .buildV1()
      );

      // Second score (20)
      lossless.ingestDelta(
        createDelta('user1', 'host1')
          .withTimestamp(2000)
          .setProperty('entity1', 'score', 20, 'collection')
          .buildV1()
      );

      // Third score (30)
      lossless.ingestDelta(
        createDelta('user1', 'host1')
          .withTimestamp(3000)
          .setProperty('entity1', 'score', 30, 'collection')
          .buildV1()
      );

      const resolver = new CustomResolver(lossless, {
        score: new RunningAveragePlugin()
      });

      const result = resolver.resolve();
      expect(result).toBeDefined();
      expect(result!['entity1'].properties.score).toBe(20); // (10 + 20 + 30) / 3
    });
  });

  describe('Edge Cases', () => {
    test('should handle empty delta sets', () => {
      const resolver = new CustomResolver(lossless, {
        name: new LastWriteWinsPlugin()
      });

      const result = resolver.resolve();
      expect(result).toBeDefined();
      expect(Object.keys(result!)).toHaveLength(0);
    });

    test('should handle non-matching property types gracefully', () => {
      // Add string value to numeric plugin
      lossless.ingestDelta(
        createDelta('user1', 'host1')
          .withTimestamp(1000)
          .setProperty('entity1', 'score', 'not_a_number', 'collection')
          .buildV1()
      );

      const resolver = new CustomResolver(lossless, {
        score: new MinPlugin() // Expects numeric values
      });

      const result = resolver.resolve();
      expect(result).toBeDefined();
      // The entity might not be present in the result if no properties were resolved
      if (result!['entity1']) {
        expect(result!['entity1'].properties).toBeDefined();
        expect(result!['entity1'].properties).not.toHaveProperty('score');
      }
    });
  });
});