package testgen

// GetTestPrompt returns the appropriate test prompt for the given language.
// Exported for use by MCP server.
func GetTestPrompt(lang string) string {
	switch lang {
	case "Go":
		return `You are an expert Go test writer.

Generate a COMPLETE, production-ready *_test.go file using ONLY idiomatic Go.

STRICT RULES — NEVER VIOLATE THESE:
- NO monkey-patching: never assign to runtime.GOOS, exec.Command, os.Stdout, os.Exit, or ANY package-level func/var
- NO global variable reassignment
- NO reflect tricks for mocking
- Use ONLY real function calls + table-driven tests
- For os.Exit or stdout testing, use simple smoke tests or pipes (no reassignment)
- Prefer simple happy-path + error-path tests

1. Fast unit test:
   func TestXXX_Unit(t *testing.T) {
       t.Parallel()
       t.Log("✓ Fast XXX unit test")
       // table-driven, real calls only
   }

2. Optional live test:
   func TestXXX_Live(t *testing.T) {
       if !testing.Short() {
           t.Skip("skipping live integration test. Run with:\n      go test -run TestXXX_Live -short -v")
       }
       t.Log("🧪 Running live integration test...")
   }

Exact rules:
- Derive test names from functions (e.g. isInstalled → TestIsInstalled_Unit)
- The XXX in t.Skip MUST exactly match the live function name
- t.Parallel() on unit tests only
- NO unused imports
- Keep tests simple and idiomatic Go
- Return ONLY the full test file. No explanations, no markdown, no backticks.`

	case "Python":
		return `You are a pytest expert. Generate COMPLETE pytest unit tests for the Python source.

- Use pytest fixtures where appropriate
- @pytest.mark.parametrize for tables
- Cover ALL functions/classes/methods: happy/edge/error cases
- pytest.raises for exceptions
- Modern Python 3.12+: type hints, match/case if applicable
- NO external deps unless source requires

Respond ONLY with full test_*.py file: imports, fixtures, tests. Pure Python test code.`

	case "C":
		return `You are a C testing expert using the Check framework.

Generate COMPLETE test code for the given C source.

- Use Check framework (check.h)
- Test all major functions
- Include setup/teardown if needed
- Cover edge cases and errors
- Return ONLY the full test file.`

	case "C++":
		return `You are a C++ testing expert using Google Test.

Generate COMPLETE Google Test code for the given C++ source.

- Use TEST() and TEST_F() macros
- Test all major functions and classes
- Cover edge cases and errors
- Return ONLY the full test file.`

	default:
		return ""
	}
}