import { describe, it, expect, beforeEach } from 'vitest';
import {
  renderTemplate,
  createDefaultContext,
  createPlanContext,
  DEFAULT_TOOL_NAMES,
} from '../../../src/agent/prompt-template/index.js';
import type { PromptContext } from '../../../src/agent/prompt-template/types.js';

describe('Prompt Template System', () => {
  let context: PromptContext;

  beforeEach(() => {
    context = createDefaultContext({
      plan: {
        isActive: true,
        planExists: false,
        planFilePath: '/tmp/test-plan.md',
        allowedWritePaths: ['/tmp/*'],
      },
      env: {
        workdir: '/test/project',
        isGitRepo: true,
        platform: 'darwin',
        date: '2024-01-01',
        homeDir: '/home/test',
      },
      agent: {
        name: 'test-agent',
        mode: 'primary',
        isSubagent: false,
      },
    });
  });

  describe('renderTemplate', () => {
    it('should replace simple variables', () => {
      const template = 'Use ${tools.glob} to find files';
      const result = renderTemplate(template, context);
      expect(result).toBe('Use glob to find files');
    });

    it('should replace nested properties', () => {
      const template = 'Plan file: ${plan.planFilePath}';
      const result = renderTemplate(template, context);
      expect(result).toBe('Plan file: /tmp/test-plan.md');
    });

    it('should handle multiple variables in one template', () => {
      const template = 'Use ${tools.glob}, ${tools.grep}, and ${tools.read}';
      const result = renderTemplate(template, context);
      expect(result).toBe('Use glob, grep, and read_file');
    });

    it('should handle ternary expressions - false condition', () => {
      const template = '${plan.planExists ? "exists" : "not exists"}';
      const result = renderTemplate(template, context);
      expect(result).toBe('not exists');
    });

    it('should handle ternary expressions - true condition', () => {
      context.plan.planExists = true;
      const template = '${plan.planExists ? "exists" : "not exists"}';
      const result = renderTemplate(template, context);
      expect(result).toBe('exists');
    });

    it('should handle nested variables in ternary expressions', () => {
      const template =
        '${plan.planExists ? "File at ${plan.planFilePath}" : "Create at ${plan.planFilePath}"}';
      const result = renderTemplate(template, context);
      expect(result).toBe('Create at /tmp/test-plan.md');
    });

    it('should handle boolean values', () => {
      const template = 'Is git repo: ${env.isGitRepo}';
      const result = renderTemplate(template, context);
      expect(result).toBe('Is git repo: true');
    });

    it('should handle undefined variables gracefully', () => {
      const template = 'Value: ${custom.undefined}';
      const result = renderTemplate(template, context);
      expect(result).toBe('Value: ');
    });

    it('should preserve text without variables', () => {
      const template = 'No variables here';
      const result = renderTemplate(template, context);
      expect(result).toBe('No variables here');
    });

    it('should handle complex nested ternary with tool references', () => {
      context.plan.planExists = true;
      const template =
        '${plan.planExists ? "Edit with ${tools.edit}" : "Write with ${tools.write}"}';
      const result = renderTemplate(template, context);
      expect(result).toBe('Edit with edit_file');
    });
  });

  describe('createDefaultContext', () => {
    it('should create context with default tool names', () => {
      const ctx = createDefaultContext();
      expect(ctx.tools.glob).toBe('glob');
      expect(ctx.tools.grep).toBe('grep');
      expect(ctx.tools.read).toBe('read_file');
      expect(ctx.tools.write).toBe('write_file');
      expect(ctx.tools.bash).toBe('bash');
    });

    it('should allow overriding tool names', () => {
      const ctx = createDefaultContext({
        tools: {
          ...DEFAULT_TOOL_NAMES,
          glob: 'custom_glob',
        },
      });
      expect(ctx.tools.glob).toBe('custom_glob');
      expect(ctx.tools.grep).toBe('grep'); // Others unchanged
    });

    it('should set default plan values', () => {
      const ctx = createDefaultContext();
      expect(ctx.plan.isActive).toBe(false);
      expect(ctx.plan.planExists).toBe(false);
    });
  });

  describe('createPlanContext', () => {
    it('should create context with plan mode active', () => {
      const ctx = createPlanContext({});
      expect(ctx.plan.isActive).toBe(true);
      expect(ctx.agent.name).toBe('plan');
    });

    it('should set isSubagent correctly', () => {
      const ctx = createPlanContext({ isSubagent: true });
      expect(ctx.agent.isSubagent).toBe(true);
      expect(ctx.agent.mode).toBe('subagent');
    });

    it('should use custom workdir', () => {
      const ctx = createPlanContext({ workdir: '/custom/path' });
      expect(ctx.env.workdir).toBe('/custom/path');
    });

    it('should use custom plan file path', () => {
      const ctx = createPlanContext({ planFilePath: '/custom/plan.md' });
      expect(ctx.plan.planFilePath).toBe('/custom/plan.md');
    });
  });

  describe('Edge Cases', () => {
    it('should handle empty template', () => {
      const result = renderTemplate('', context);
      expect(result).toBe('');
    });

    it('should handle template with only variable', () => {
      const result = renderTemplate('${tools.bash}', context);
      expect(result).toBe('bash');
    });

    it('should handle unclosed variable syntax', () => {
      const result = renderTemplate('${tools.bash', context);
      expect(result).toBe('${tools.bash');
    });

    it('should handle escaped-like patterns (no real escaping)', () => {
      // Note: This system doesn't support escaping, so $$ or similar won't work
      const result = renderTemplate('Price: $100', context);
      expect(result).toBe('Price: $100');
    });

    it('should handle deeply nested properties', () => {
      const result = renderTemplate('${agent.mode}', context);
      expect(result).toBe('primary');
    });
  });
});