package skills

import (
	"os"
	"path/filepath"
	"time"
)

var builtinSkills = []Skill{
	{
		Name:        "env-setup",
		Description: "Set up a complete development environment for any language. Detects missing tools, installs them, and configures the project.",
		Author:      "muyue",
		Version:     "1.0.0",
		Target:      "both",
		Tags:        []string{"setup", "environment", "install"},
		Content: `# Environment Setup

Use this skill when setting up a new development environment or project.

## Steps

1. Detect the project type by checking for config files:
   - ` + "`go.mod`" + ` → Go
   - ` + "`package.json`" + ` → Node.js
   - ` + "`requirements.txt` / `pyproject.toml` / `setup.py`" + ` → Python
   - ` + "`Cargo.toml`" + ` → Rust
   - ` + "`pom.xml` / `build.gradle`" + ` → Java

2. Check if required tools are installed:
   - Language runtime (go, node, python, etc.)
   - Package manager (npm, pip, cargo, etc.)
   - Linter/formatter
   - Test runner

3. If tools are missing, install them using the system package manager:
   - Linux: apt/dnf/pacman
   - macOS: brew
   - Windows: winget/scoop

4. Install project dependencies:
   - ` + "`go mod download`" + ` for Go
   - ` + "`npm install`" + ` / ` + "`pnpm install`" + ` for Node.js
   - ` + "`pip install -r requirements.txt`" + ` / ` + "`uv sync`" + ` for Python
   - ` + "`cargo build`" + ` for Rust

5. Configure git hooks if ` + "`pre-commit`" + ` config exists.

6. Verify the setup by running tests or build.

## Error Handling

- If a tool cannot be installed automatically, provide the manual install command.
- If dependency installation fails, check for version conflicts and suggest fixes.
- Always check for lock files first to ensure reproducible installs.`,
	},
	{
		Name:        "git-workflow",
		Description: "Manage git branches, commits, and pull requests following best practices. Handles branching strategy, conventional commits, and PR creation.",
		Author:      "muyue",
		Version:     "1.0.0",
		Target:      "both",
		Tags:        []string{"git", "workflow", "branching", "commits"},
		Content: `# Git Workflow

Use this skill when the user needs to create branches, make commits, or manage pull requests.

## Branch Naming Convention

- ` + "`feature/<ticket>-<description>`" + ` for new features
- ` + "`fix/<ticket>-<description>`" + ` for bug fixes
- ` + "`refactor/<description>`" + ` for refactoring
- ` + "`docs/<description>`" + ` for documentation

## Commit Messages

Follow Conventional Commits:
- ` + "`feat: add user authentication`" + `
- ` + "`fix: resolve null pointer in login`" + `
- ` + "`refactor: extract validation logic`" + `
- ` + "`docs: update API documentation`" + `
- ` + "`test: add integration tests for auth`" + `
- ` + "`chore: update dependencies`" + `

## Workflow

1. Before starting, pull latest changes: ` + "`git pull --rebase origin main`" + `
2. Create branch: ` + "`git checkout -b feature/my-feature`" + `
3. Make changes and commit frequently with meaningful messages
4. Before pushing, rebase: ` + "`git rebase origin/main`" + `
5. Push: ` + "`git push -u origin feature/my-feature`" + `
6. Create PR with description following template

## PR Description Template

` + "```" + `
## Summary
<1-3 bullet points>

## Changes
- <list of key changes>

## Test Plan
- [ ] <checklist>
` + "```" + `

## Error Handling

- If rebase has conflicts, help resolve them file by file
- If push is rejected, pull with rebase first
- Never force push to main/master`,
	},
	{
		Name:        "api-design",
		Description: "Design and implement REST or GraphQL APIs following best practices. Includes endpoint design, error handling, and documentation.",
		Author:      "muyue",
		Version:     "1.0.0",
		Target:      "both",
		Tags:        []string{"api", "rest", "graphql", "design"},
		Content: `# API Design

Use this skill when designing or implementing an API.

## REST API Design Rules

1. Use nouns for resources, not verbs: ` + "`/users`" + ` not ` + "`/getUsers`" + `
2. Use plural nouns: ` + "`/users`" + ` not ` + "`/user`" + `
3. Use proper HTTP methods:
   - GET for reading
   - POST for creating
   - PUT/PATCH for updating
   - DELETE for removing
4. Use query parameters for filtering: ` + "`/users?role=admin&active=true`" + `
5. Use pagination: ` + "`/users?page=1&limit=20`" + `
6. Return proper status codes:
   - 200: Success
   - 201: Created
   - 204: No Content (successful delete)
   - 400: Bad Request
   - 401: Unauthorized
   - 403: Forbidden
   - 404: Not Found
   - 422: Validation Error
   - 500: Internal Server Error

## Error Response Format

` + "```" + `json
{
  "error": {
    "code": "VALIDATION_ERROR",
    "message": "Human readable message",
    "details": [
      {"field": "email", "message": "Invalid email format"}
    ]
  }
}
` + "```" + `

## Implementation Steps

1. Define the API spec (endpoints, request/response schemas)
2. Implement data models
3. Add validation middleware
4. Implement handlers
5. Add error handling
6. Write tests
7. Generate documentation (OpenAPI/Swagger)`,
	},
	{
		Name:        "debug-assist",
		Description: "Systematic debugging assistant. Helps identify, isolate, and fix bugs using a structured approach.",
		Author:      "muyue",
		Version:     "1.0.0",
		Target:      "both",
		Tags:        []string{"debug", "troubleshooting", "bugs"},
		Content: `# Debug Assist

Use this skill when the user reports a bug or asks for help debugging.

## Debugging Process

1. **Reproduce** — Understand the exact steps to reproduce
2. **Isolate** — Narrow down the scope:
   - Is it frontend or backend?
   - Does it happen consistently or intermittently?
   - Does it happen in all environments or just one?
3. **Hypothesize** — Form a hypothesis about the root cause
4. **Verify** — Add logging or breakpoints to confirm
5. **Fix** — Make the minimal change to fix the issue
6. **Test** — Verify the fix works and doesn't break other things
7. **Prevent** — Add a test to prevent regression

## Common Patterns

- **Null/Nil errors**: Check for missing initialization or unexpected nil values
- **Type errors**: Check API contracts and type assertions
- **Race conditions**: Look for shared mutable state without synchronization
- **Memory leaks**: Check for unclosed resources (connections, files, channels)
- **Off-by-one**: Check loop bounds and array indexing
- **State issues**: Check if state is properly reset between operations

## Debugging Commands

- Check logs: Look for error messages and stack traces
- Check recent changes: ` + "`git diff HEAD~5`" + ` to see what changed
- Check dependencies: Verify versions match expected
- Check environment: Compare config between working and broken environments`,
	},
	{
		Name:        "code-review",
		Description: "Perform a thorough code review. Checks for bugs, security issues, performance problems, and style consistency.",
		Author:      "muyue",
		Version:     "1.0.0",
		Target:      "both",
		Tags:        []string{"review", "quality", "security"},
		Content: `# Code Review

Use this skill when reviewing code changes or pull requests.

## Review Checklist

### Correctness
- Does the code do what it's supposed to?
- Are edge cases handled?
- Are there off-by-one errors?
- Are error paths handled?

### Security
- Is user input sanitized?
- Are there SQL injection risks?
- Are secrets hardcoded?
- Are authentication/authorization checks in place?
- Is sensitive data logged?

### Performance
- Are there N+1 queries?
- Are there unnecessary loops or computations?
- Is caching used where appropriate?
- Are large allocations avoided?

### Readability
- Are names descriptive?
- Is the code self-documenting?
- Are complex parts commented?
- Is the code modular?

### Testing
- Are there unit tests?
- Are edge cases tested?
- Are error paths tested?
- Are tests independent and deterministic?

## Review Format

1. Summary of changes
2. Issues found (critical → minor)
3. Suggestions for improvement
4. Positive observations

## Severity Levels

- **Critical**: Security vulnerabilities, data loss risks, crashes
- **Major**: Bugs, performance issues, missing error handling
- **Minor**: Style issues, naming, minor refactoring opportunities
- **Suggestion**: Alternative approaches, improvements`,
	},
}

func InstallBuiltinSkills() error {
	dir, err := SkillsDir()
	if err != nil {
		return err
	}

	for _, s := range builtinSkills {
		skillDir := filepath.Join(dir, s.Name)
		skillPath := filepath.Join(skillDir, "SKILL.md")

		if _, err := os.Stat(skillPath); err == nil {
			continue
		}

		s.CreatedAt = time.Now()
		s.UpdatedAt = time.Now()

		if err := os.MkdirAll(skillDir, 0755); err != nil {
			return err
		}

		content := renderSkill(&s)
		if err := os.WriteFile(skillPath, []byte(content), 0644); err != nil {
			return err
		}
	}

	return nil
}