import { describe, it, expect, beforeEach } from 'vitest';
import type { MyceliumGraphData, MetaState, RunState } from '../src/run/types';
import { RunPhase } from '../src/run/types';
import { createMetaState } from '../src/run/meta';
import {
  createMyceliumGraph,
  depositKnowledge,
  getNode,
  getEdge,
  getNodesByType,
  getConnectedNodes,
  getGraphStats,
} from '../src/mycelium/graph';
import {
  extractMemoryFlashes,
  generateFlashText,
} from '../src/mycelium/knowledge';
import {
  createMycosisState,
  updateMycosis,
  getMycosisVisuals,
} from '../src/mycelium/mycosis';
import {
  getAvailableBonuses,
  purchaseBonus,
  canAffordBonus,
} from '../src/mycelium/shop';
import {
  spawnFungalNodes,
} from '../src/mycelium/nodes';
import type { MycosisState, MemoryFlash, FungalNodeInfo } from '../src/mycelium/types';
import { MYCOSIS_CONFIG } from '../src/mycelium/types';

// ─── Test helpers ────────────────────────────────────────────────

function createTestRunState(runId: number = 1): RunState {
  return {
    runId,
    schoolId: 'alchemist',
    phase: RunPhase.Exploration,
    phaseTimer: 0,
    elapsed: 60000,
    escalation: 0,
    crisisActive: false,
    crisisResolved: false,
    discoveries: {
      elements: new Set(['Na', 'Cl', 'H', 'O']),
      reactions: new Set(['Na+Cl']),
      compounds: new Set(['NaCl']),
      creatures: new Set(['crystallid']),
    },
    alive: true,
  };
}

function createTestMeta(): MetaState {
  const meta = createMetaState();
  meta.totalRuns = 2;
  meta.spores = 100;
  meta.mycelium = createMyceliumGraph();
  return meta;
}

// ─── Mycelium Graph Tests ────────────────────────────────────────

describe('Mycelium Graph', () => {
  let graph: MyceliumGraphData;

  beforeEach(() => {
    graph = createMyceliumGraph();
  });

  it('should create an empty graph', () => {
    expect(graph.nodes).toHaveLength(0);
    expect(graph.edges).toHaveLength(0);
    expect(graph.totalDeposits).toBe(0);
    expect(graph.totalExtractions).toBe(0);
  });

  it('should deposit element knowledge from a run', () => {
    const run = createTestRunState(1);
    const result = depositKnowledge(graph, run);

    expect(result.newNodes).toBeGreaterThan(0);
    // Should have nodes for elements + reactions + compounds + creatures
    expect(graph.nodes.length).toBeGreaterThanOrEqual(4);
    expect(graph.totalDeposits).toBe(1);
  });

  it('should create nodes for all discovery types', () => {
    const run = createTestRunState(1);
    depositKnowledge(graph, run);

    // 4 elements (Na, Cl, H, O) + 1 reaction + 1 compound + 1 creature = 7
    expect(graph.nodes).toHaveLength(7);

    const elementNodes = getNodesByType(graph, 'element');
    expect(elementNodes).toHaveLength(4);

    const reactionNodes = getNodesByType(graph, 'reaction');
    expect(reactionNodes).toHaveLength(1);

    const compoundNodes = getNodesByType(graph, 'compound');
    expect(compoundNodes).toHaveLength(1);

    const creatureNodes = getNodesByType(graph, 'creature');
    expect(creatureNodes).toHaveLength(1);
  });

  it('should create edges between related discoveries', () => {
    const run = createTestRunState(1);
    depositKnowledge(graph, run);

    // Elements that form a reaction should be connected to the reaction
    // Na + Cl → NaCl: edges Na→reaction, Cl→reaction, reaction→compound
    expect(graph.edges.length).toBeGreaterThan(0);
  });

  it('should strengthen existing nodes on re-deposit', () => {
    const run1 = createTestRunState(1);
    depositKnowledge(graph, run1);

    const naNode = getNode(graph, 'element:Na');
    expect(naNode).toBeDefined();
    const initialStrength = naNode!.strength;

    // Second deposit with same discoveries should strengthen
    const run2 = createTestRunState(2);
    run2.discoveries.elements = new Set(['Na']); // Only Na
    run2.discoveries.reactions = new Set();
    run2.discoveries.compounds = new Set();
    run2.discoveries.creatures = new Set();
    const result = depositKnowledge(graph, run2);

    expect(result.strengthened).toBe(1);
    expect(result.newNodes).toBe(0);

    const naNodeAfter = getNode(graph, 'element:Na');
    expect(naNodeAfter!.strength).toBeGreaterThan(initialStrength);
  });

  it('should cap node strength at 1.0', () => {
    const run = createTestRunState(1);
    run.discoveries.elements = new Set(['Na']);
    run.discoveries.reactions = new Set();
    run.discoveries.compounds = new Set();
    run.discoveries.creatures = new Set();

    // Deposit many times
    for (let i = 0; i < 20; i++) {
      depositKnowledge(graph, run);
    }

    const naNode = getNode(graph, 'element:Na');
    expect(naNode!.strength).toBeLessThanOrEqual(1.0);
  });

  it('should look up nodes by ID', () => {
    const run = createTestRunState(1);
    depositKnowledge(graph, run);

    const node = getNode(graph, 'element:Na');
    expect(node).toBeDefined();
    expect(node!.type).toBe('element');
    expect(node!.knowledgeId).toBe('Na');

    const missing = getNode(graph, 'element:Au');
    expect(missing).toBeUndefined();
  });

  it('should look up edges between nodes', () => {
    const run = createTestRunState(1);
    depositKnowledge(graph, run);

    // There should be edges from Na and Cl to the Na+Cl reaction
    const naEdge = getEdge(graph, 'element:Na', 'reaction:Na+Cl');
    // Edge may exist in either direction — check both
    const naEdgeReverse = getEdge(graph, 'reaction:Na+Cl', 'element:Na');
    expect(naEdge ?? naEdgeReverse).toBeDefined();
  });

  it('should return connected nodes', () => {
    const run = createTestRunState(1);
    depositKnowledge(graph, run);

    // Na should be connected to the Na+Cl reaction
    const connected = getConnectedNodes(graph, 'element:Na');
    expect(connected.length).toBeGreaterThan(0);
  });

  it('should report graph statistics', () => {
    const run = createTestRunState(1);
    depositKnowledge(graph, run);

    const stats = getGraphStats(graph);
    expect(stats.nodeCount).toBe(7);
    expect(stats.edgeCount).toBeGreaterThan(0);
    expect(stats.totalDeposits).toBe(1);
    expect(stats.averageStrength).toBeGreaterThan(0);
    expect(stats.averageStrength).toBeLessThanOrEqual(1);
  });
});

// ─── Knowledge System Tests ──────────────────────────────────────

describe('Knowledge System', () => {
  let graph: MyceliumGraphData;

  beforeEach(() => {
    graph = createMyceliumGraph();
    const run = createTestRunState(1);
    depositKnowledge(graph, run);
  });

  it('should extract memory flashes from populated graph', () => {
    const flashes = extractMemoryFlashes(graph, 3);
    expect(flashes.length).toBeGreaterThan(0);
    expect(flashes.length).toBeLessThanOrEqual(3);
  });

  it('should return empty flashes from empty graph', () => {
    const emptyGraph = createMyceliumGraph();
    const flashes = extractMemoryFlashes(emptyGraph, 3);
    expect(flashes).toHaveLength(0);
  });

  it('should generate flash text for element hints', () => {
    const flash = generateFlashText('element', 'Na');
    expect(flash.type).toBe('element_hint');
    expect(flash.text.length).toBeGreaterThan(0);
    expect(flash.textRu.length).toBeGreaterThan(0);
    // Should contain the element name somewhere
    expect(flash.text).toContain('Na');
    expect(flash.textRu).toContain('Na');
  });

  it('should generate flash text for reaction hints', () => {
    const flash = generateFlashText('reaction', 'Na+Cl');
    expect(flash.type).toBe('reaction_hint');
    expect(flash.text.length).toBeGreaterThan(0);
  });

  it('should generate flash text for creature hints', () => {
    const flash = generateFlashText('creature', 'crystallid');
    expect(flash.type).toBe('creature_hint');
    expect(flash.text.length).toBeGreaterThan(0);
  });

  it('should increment extraction counter', () => {
    expect(graph.totalExtractions).toBe(0);
    extractMemoryFlashes(graph, 3);
    expect(graph.totalExtractions).toBe(1);
  });

  it('should prefer stronger nodes for flashes', () => {
    // Strengthen Na by depositing multiple times
    for (let i = 0; i < 5; i++) {
      const run = createTestRunState(i + 2);
      run.discoveries.elements = new Set(['Na']);
      run.discoveries.reactions = new Set();
      run.discoveries.compounds = new Set();
      run.discoveries.creatures = new Set();
      depositKnowledge(graph, run);
    }

    // Extract many flashes — Na should appear frequently
    let naCount = 0;
    for (let i = 0; i < 10; i++) {
      const flashes = extractMemoryFlashes(graph, 3);
      for (const f of flashes) {
        if (f.text.includes('Na') || f.textRu.includes('Na')) naCount++;
      }
    }
    // Na should appear at least once in 10 rounds of 3 flashes
    expect(naCount).toBeGreaterThan(0);
  });
});

// ─── Mycosis Tests ───────────────────────────────────────────────

describe('Mycosis', () => {
  let state: MycosisState;

  beforeEach(() => {
    state = createMycosisState();
  });

  it('should create initial mycosis state at zero', () => {
    expect(state.level).toBe(0);
    expect(state.exposure).toBe(0);
    expect(state.revealing).toBe(false);
  });

  it('should increase level when near a fungal node', () => {
    updateMycosis(state, 1000, true); // 1 second near a node
    expect(state.level).toBeGreaterThan(0);
    expect(state.exposure).toBe(1000);
  });

  it('should decrease level when away from nodes', () => {
    // Build up some mycosis
    updateMycosis(state, 5000, true);
    const peakLevel = state.level;

    // Move away
    updateMycosis(state, 2000, false);
    expect(state.level).toBeLessThan(peakLevel);
  });

  it('should not go below zero', () => {
    updateMycosis(state, 10000, false);
    expect(state.level).toBe(0);
  });

  it('should not exceed max level', () => {
    updateMycosis(state, 100000, true); // Very long exposure
    expect(state.level).toBeLessThanOrEqual(MYCOSIS_CONFIG.maxLevel);
  });

  it('should start revealing at threshold', () => {
    // Build up to reveal threshold
    const timeToThreshold = MYCOSIS_CONFIG.revealThreshold / MYCOSIS_CONFIG.buildRate * 1000;
    updateMycosis(state, timeToThreshold + 1000, true);
    expect(state.revealing).toBe(true);
  });

  it('should stop revealing when level drops below threshold', () => {
    // Build up past threshold
    const timeToThreshold = MYCOSIS_CONFIG.revealThreshold / MYCOSIS_CONFIG.buildRate * 1000;
    updateMycosis(state, timeToThreshold + 2000, true);
    expect(state.revealing).toBe(true);

    // Let it decay
    const decayTime = (state.level - MYCOSIS_CONFIG.revealThreshold + 0.1) / MYCOSIS_CONFIG.decayRate * 1000;
    updateMycosis(state, decayTime + 1000, false);
    expect(state.revealing).toBe(false);
  });

  it('should return visual parameters based on level', () => {
    updateMycosis(state, 5000, true);

    const visuals = getMycosisVisuals(state);
    expect(visuals.tintColor).toBe(MYCOSIS_CONFIG.tintColor);
    expect(visuals.tintAlpha).toBeGreaterThan(0);
    expect(visuals.tintAlpha).toBeLessThanOrEqual(MYCOSIS_CONFIG.maxTintAlpha);
    expect(visuals.distortionStrength).toBeGreaterThanOrEqual(0);
  });

  it('should have zero visuals when mycosis is zero', () => {
    const visuals = getMycosisVisuals(state);
    expect(visuals.tintAlpha).toBe(0);
    expect(visuals.distortionStrength).toBe(0);
  });
});

// ─── Spore Shop Tests ────────────────────────────────────────────

describe('Spore Shop', () => {
  it('should list available bonuses', () => {
    const bonuses = getAvailableBonuses();
    expect(bonuses.length).toBeGreaterThan(0);

    // Each bonus should have required fields
    for (const bonus of bonuses) {
      expect(bonus.id).toBeTruthy();
      expect(bonus.nameRu).toBeTruthy();
      expect(bonus.cost).toBeGreaterThan(0);
      expect(bonus.effect).toBeDefined();
    }
  });

  it('should check affordability correctly', () => {
    const meta = createTestMeta();
    meta.spores = 15;

    const bonuses = getAvailableBonuses();
    const cheapBonus = bonuses.find(b => b.cost <= 15);
    const expensiveBonus = bonuses.find(b => b.cost > 15);

    if (cheapBonus) {
      expect(canAffordBonus(meta, cheapBonus.id)).toBe(true);
    }
    if (expensiveBonus) {
      expect(canAffordBonus(meta, expensiveBonus.id)).toBe(false);
    }
  });

  it('should deduct spores on purchase', () => {
    const meta = createTestMeta();
    const initialSpores = meta.spores;

    const bonuses = getAvailableBonuses();
    const bonus = bonuses[0];
    const result = purchaseBonus(meta, bonus.id);

    expect(result).not.toBeNull();
    expect(meta.spores).toBe(initialSpores - bonus.cost);
  });

  it('should return the purchased effect', () => {
    const meta = createTestMeta();
    const bonuses = getAvailableBonuses();
    const bonus = bonuses.find(b => b.effect.type === 'extra_health');
    expect(bonus).toBeDefined();

    const result = purchaseBonus(meta, bonus!.id);
    expect(result).not.toBeNull();
    expect(result!.type).toBe('extra_health');
  });

  it('should fail to purchase with insufficient spores', () => {
    const meta = createTestMeta();
    meta.spores = 0;

    const bonuses = getAvailableBonuses();
    const result = purchaseBonus(meta, bonuses[0].id);
    expect(result).toBeNull();
    expect(meta.spores).toBe(0); // unchanged
  });

  it('should not allow non-repeatable bonuses to be purchased twice', () => {
    const meta = createTestMeta();
    meta.spores = 200;

    const bonuses = getAvailableBonuses();
    const nonRepeatable = bonuses.find(b => !b.repeatable);
    if (!nonRepeatable) return; // skip if all are repeatable

    const result1 = purchaseBonus(meta, nonRepeatable.id);
    expect(result1).not.toBeNull();

    const result2 = purchaseBonus(meta, nonRepeatable.id);
    expect(result2).toBeNull();
  });
});

// ─── Fungal Node Spawning Tests ──────────────────────────────────

describe('Fungal Node Spawning', () => {
  // Build a simple 20x20 grid with walkable ground
  const biome = {
    id: 'test',
    name: 'Test',
    nameRu: 'Тест',
    description: '',
    descriptionRu: '',
    tileSize: 16,
    mapWidth: 20,
    mapHeight: 20,
    tiles: [
      { id: 0, name: 'ground', nameRu: 'земля', color: '#555', walkable: true, damage: 0, interactive: false, resource: false },
      { id: 1, name: 'acid-deep', nameRu: 'кислота', color: '#0f0', walkable: false, damage: 5, interactive: false, resource: false },
      { id: 2, name: 'scorched-earth', nameRu: 'выжженная', color: '#333', walkable: true, damage: 0, interactive: false, resource: false },
    ],
    generation: {
      elevationScale: 0.1,
      detailScale: 0.2,
      elevationRules: [{ below: 0.5, tileId: 0 }],
      geyserThreshold: 0.9,
      mineralThreshold: 0.8,
      geyserOnTile: 0,
      mineralOnTiles: [0],
    },
  };

  function createTestGrid(): number[][] {
    const grid: number[][] = [];
    for (let y = 0; y < 20; y++) {
      const row: number[] = [];
      for (let x = 0; x < 20; x++) {
        // Mostly ground, some acid
        row.push(x === 0 && y === 0 ? 1 : 0);
      }
      grid.push(row);
    }
    return grid;
  }

  it('should spawn fungal nodes on walkable tiles', async () => {
    const { createWorld } = await import('bitecs');
    const world = createWorld();
    const grid = createTestGrid();

    const nodeData = spawnFungalNodes(world, grid, biome, 42);
    expect(nodeData.size).toBeGreaterThan(0);
  });

  it('should not spawn on non-walkable tiles', async () => {
    const { createWorld } = await import('bitecs');
    const world = createWorld();

    // Make grid entirely non-walkable
    const grid: number[][] = [];
    for (let y = 0; y < 20; y++) {
      grid.push(Array(20).fill(1)); // all acid
    }

    const nodeData = spawnFungalNodes(world, grid, biome, 42);
    expect(nodeData.size).toBe(0);
  });

  it('should use deterministic placement based on seed', async () => {
    const { createWorld } = await import('bitecs');
    const grid = createTestGrid();

    const world1 = createWorld();
    const data1 = spawnFungalNodes(world1, grid, biome, 42);

    const world2 = createWorld();
    const data2 = spawnFungalNodes(world2, grid, biome, 42);

    // Same seed → same positions
    const positions1 = [...data1.values()].map(d => `${d.tileX},${d.tileY}`).sort();
    const positions2 = [...data2.values()].map(d => `${d.tileX},${d.tileY}`).sort();
    expect(positions1).toEqual(positions2);
  });

  it('should maintain minimum spacing between nodes', async () => {
    const { createWorld } = await import('bitecs');
    const world = createWorld();
    const grid = createTestGrid();

    const nodeData = spawnFungalNodes(world, grid, biome, 42);
    const positions = [...nodeData.values()].map(d => ({ x: d.tileX, y: d.tileY }));

    // No two nodes should be closer than minSpacing
    // (on a 20x20 grid with spacing 8, there can be only a few nodes)
    for (let i = 0; i < positions.length; i++) {
      for (let j = i + 1; j < positions.length; j++) {
        const dx = positions[i].x - positions[j].x;
        const dy = positions[i].y - positions[j].y;
        const dist = Math.sqrt(dx * dx + dy * dy);
        expect(dist).toBeGreaterThanOrEqual(7); // slight tolerance
      }
    }
  });
});