import { describe, it, expect, beforeEach } from "vitest";
import { Test, TestingModule } from "@nestjs/testing";
import { PromptFormatterService, PromptContext } from "./prompt-formatter.service";

describe("PromptFormatterService", () => {
  let service: PromptFormatterService;

  const mockPersonality = {
    id: "personality-123",
    workspaceId: "workspace-123",
    name: "Professional",
    description: "Professional communication style",
    tone: "professional",
    formalityLevel: "FORMAL" as const,
    systemPromptTemplate: "You are a helpful assistant for {{userName}} at {{workspaceName}}.",
    isDefault: true,
    isActive: true,
    createdAt: new Date(),
    updatedAt: new Date(),
  };

  beforeEach(async () => {
    const module: TestingModule = await Test.createTestingModule({
      providers: [PromptFormatterService],
    }).compile();

    service = module.get<PromptFormatterService>(PromptFormatterService);
  });

  describe("formatPrompt", () => {
    it("should format prompt with context variables", () => {
      const context: PromptContext = { userName: "John", workspaceName: "Acme Corp" };
      const result = service.formatPrompt(mockPersonality, context);
      expect(result.systemPrompt).toContain("John");
      expect(result.systemPrompt).toContain("Acme Corp");
      expect(result.metadata.personalityId).toBe(mockPersonality.id);
    });

    it("should add formality modifier", () => {
      const result = service.formatPrompt(mockPersonality);
      expect(result.systemPrompt).toContain("professional");
    });

    it("should include metadata", () => {
      const result = service.formatPrompt(mockPersonality);
      expect(result.metadata.formattedAt).toBeInstanceOf(Date);
      expect(result.metadata.tone).toBe("professional");
    });

    it("should handle custom context variables", () => {
      const personality = { ...mockPersonality, systemPromptTemplate: "Custom: {{customVar}}" };
      const context: PromptContext = { custom: { customVar: "test-value" } };
      const result = service.formatPrompt(personality, context);
      expect(result.systemPrompt).toContain("test-value");
    });
  });

  describe("buildSystemPrompt", () => {
    it("should build complete prompt with context", () => {
      const context: PromptContext = { userName: "Jane" };
      const result = service.buildSystemPrompt(mockPersonality, context);
      expect(result).toContain("Jane");
    });

    it("should include date/time when requested", () => {
      const context: PromptContext = { currentDate: "2024-01-29", currentTime: "14:30", timezone: "UTC" };
      const result = service.buildSystemPrompt(mockPersonality, context, { includeDateTime: true });
      expect(result).toContain("2024-01-29");
      expect(result).toContain("14:30");
    });

    it("should include additional instructions", () => {
      const result = service.buildSystemPrompt(mockPersonality, undefined, {
        additionalInstructions: "Be concise.",
      });
      expect(result).toContain("Be concise.");
    });
  });

  describe("validateTemplate", () => {
    it("should validate known variables", () => {
      const template = "Hello {{userName}}, welcome to {{workspaceName}}!";
      const result = service.validateTemplate(template);
      expect(result.valid).toBe(true);
    });

    it("should report unknown variables", () => {
      const template = "Hello {{unknownVar}}!";
      const result = service.validateTemplate(template);
      expect(result.valid).toBe(false);
      expect(result.missingVariables).toContain("unknownVar");
    });

    it("should allow custom_ prefixed variables", () => {
      const template = "Value: {{custom_myVar}}";
      const result = service.validateTemplate(template);
      expect(result.valid).toBe(true);
    });
  });

  describe("getFormalityLevels", () => {
    it("should return all formality levels", () => {
      const levels = service.getFormalityLevels();
      expect(levels).toHaveLength(5);
      expect(levels.map((l) => l.level)).toContain("FORMAL");
    });
  });
});