//! TDD Expansion Framework
//! 
//! This module provides tools to apply TDD principles to other packages
//! in the workspace, ensuring consistent quality and testing standards.

use anyhow::Result;
use std::collections::HashMap;
use std::path::{Path, PathBuf};

/// TDD Expansion Manager for applying TDD principles across workspace packages
pub struct TddExpansionManager {
    workspace_root: PathBuf,
    package_configs: HashMap<String, PackageTddConfig>,
}

/// Configuration for TDD implementation in a package
#[derive(Debug, Clone)]
pub struct PackageTddConfig {
    pub package_name: String,
    pub package_path: PathBuf,
    pub test_categories: Vec<TestCategory>,
    pub performance_contracts: Option<PerformanceContractConfig>,
    pub dependency_contracts: bool,
    pub api_contracts: bool,
    pub integration_tests: bool,
}

/// Test categories to implement
#[derive(Debug, Clone)]
pub enum TestCategory {
    Unit,
    Integration,
    Performance,
    Contract,
    Accessibility,
    Security,
}

/// Performance contract configuration
#[derive(Debug, Clone)]
pub struct PerformanceContractConfig {
    pub max_bundle_size_kb: f64,
    pub max_render_time_ms: f64,
    pub max_memory_usage_mb: f64,
    pub max_dependency_count: usize,
}

/// TDD Implementation Status
#[derive(Debug, Clone)]
pub struct TddImplementationStatus {
    pub package_name: String,
    pub overall_score: f64, // 0.0 to 1.0
    pub test_coverage: f64,
    pub contract_compliance: f64,
    pub performance_score: f64,
    pub missing_components: Vec<String>,
    pub recommendations: Vec<String>,
}

impl TddExpansionManager {
    pub fn new(workspace_root: PathBuf) -> Self {
        Self {
            workspace_root,
            package_configs: HashMap::new(),
        }
    }

    /// Scan workspace and identify packages that need TDD implementation
    pub fn scan_workspace(&mut self) -> Result<Vec<String>> {
        let mut packages_needing_tdd = Vec::new();
        
        // Read workspace Cargo.toml
        let workspace_toml = self.workspace_root.join("Cargo.toml");
        let content = std::fs::read_to_string(&workspace_toml)?;
        
        // Parse workspace members
        let mut in_members = false;
        for line in content.lines() {
            let line = line.trim();
            
            if line.starts_with("[workspace]") {
                in_members = false;
            } else if line.starts_with("members = [") {
                in_members = true;
            } else if in_members && line.starts_with('"') && line.ends_with('"') {
                let package_path = line.trim_matches('"').trim_end_matches(',');
                if let Some(package_name) = self.analyze_package_for_tdd(package_path)? {
                    packages_needing_tdd.push(package_name);
                }
            }
        }
        
        Ok(packages_needing_tdd)
    }

    /// Analyze a package to determine TDD implementation needs
    fn analyze_package_for_tdd(&mut self, package_path: &str) -> Result<Option<String>> {
        let full_path = self.workspace_root.join(package_path);
        let cargo_toml = full_path.join("Cargo.toml");
        
        if !cargo_toml.exists() {
            return Ok(None);
        }
        
        let content = std::fs::read_to_string(&cargo_toml)?;
        let package_name = self.extract_package_name(&content)?;
        
        // Check if package already has TDD implementation
        let tdd_score = self.calculate_tdd_score(&full_path)?;
        
        if tdd_score < 0.7 {
            // Package needs TDD implementation
            let config = self.create_tdd_config(&package_name, &full_path)?;
            self.package_configs.insert(package_name.clone(), config);
            Ok(Some(package_name))
        } else {
            Ok(None)
        }
    }

    /// Extract package name from Cargo.toml content
    fn extract_package_name(&self, content: &str) -> Result<String> {
        for line in content.lines() {
            let line = line.trim();
            if line.starts_with("name = \"") {
                let name = line
                    .strip_prefix("name = \"")
                    .and_then(|s| s.strip_suffix('"'))
                    .ok_or_else(|| anyhow::anyhow!("Invalid package name format"))?;
                return Ok(name.to_string());
            }
        }
        Err(anyhow::anyhow!("Package name not found"))
    }

    /// Calculate TDD implementation score for a package
    fn calculate_tdd_score(&self, package_path: &Path) -> Result<f64> {
        let mut score = 0.0;
        let mut total_checks = 0.0;

        // Check for test directory
        total_checks += 1.0;
        if package_path.join("tests").exists() || package_path.join("src").join("tests").exists() {
            score += 1.0;
        }

        // Check for integration tests
        total_checks += 1.0;
        if package_path.join("tests").exists() {
            score += 1.0;
        }

        // Check for benchmarks
        total_checks += 1.0;
        if package_path.join("benches").exists() {
            score += 1.0;
        }

        // Check for contract testing
        total_checks += 1.0;
        if self.has_contract_tests(package_path)? {
            score += 1.0;
        }

        // Check for performance tests
        total_checks += 1.0;
        if self.has_performance_tests(package_path)? {
            score += 1.0;
        }

        // Check for documentation tests
        total_checks += 1.0;
        if self.has_doc_tests(package_path)? {
            score += 1.0;
        }

        Ok(if total_checks > 0.0 { score / total_checks } else { 0.0 })
    }

    /// Check if package has contract tests
    fn has_contract_tests(&self, package_path: &Path) -> Result<bool> {
        let src_path = package_path.join("src");
        if !src_path.exists() {
            return Ok(false);
        }

        for entry in std::fs::read_dir(&src_path)? {
            let entry = entry?;
            let path = entry.path();
            
            if path.is_file() {
                if let Some(content) = std::fs::read_to_string(&path).ok() {
                    if content.contains("contract") && content.contains("test") {
                        return Ok(true);
                    }
                }
            }
        }
        
        Ok(false)
    }

    /// Check if package has performance tests
    fn has_performance_tests(&self, package_path: &Path) -> Result<bool> {
        let benches_path = package_path.join("benches");
        if benches_path.exists() {
            return Ok(true);
        }

        // Check for performance-related test code
        let src_path = package_path.join("src");
        if src_path.exists() {
            for entry in std::fs::read_dir(&src_path)? {
                let entry = entry?;
                let path = entry.path();
                
                if path.is_file() {
                    if let Some(content) = std::fs::read_to_string(&path).ok() {
                        if content.contains("benchmark") || content.contains("performance") {
                            return Ok(true);
                        }
                    }
                }
            }
        }
        
        Ok(false)
    }

    /// Check if package has documentation tests
    fn has_doc_tests(&self, package_path: &Path) -> Result<bool> {
        let src_path = package_path.join("src");
        if !src_path.exists() {
            return Ok(false);
        }

        for entry in std::fs::read_dir(&src_path)? {
            let entry = entry?;
            let path = entry.path();
            
            if path.is_file() {
                if let Some(content) = std::fs::read_to_string(&path).ok() {
                    if content.contains("///") && content.contains("```") {
                        return Ok(true);
                    }
                }
            }
        }
        
        Ok(false)
    }

    /// Create TDD configuration for a package
    fn create_tdd_config(&self, package_name: &str, package_path: &Path) -> Result<PackageTddConfig> {
        let test_categories = vec![
            TestCategory::Unit,
            TestCategory::Integration,
            TestCategory::Contract,
        ];

        // Add performance contracts for component packages
        let performance_contracts = if package_name.contains("leptos-shadcn") {
            Some(PerformanceContractConfig {
                max_bundle_size_kb: 500.0,
                max_render_time_ms: 16.0,
                max_memory_usage_mb: 100.0,
                max_dependency_count: 10,
            })
        } else {
            None
        };

        Ok(PackageTddConfig {
            package_name: package_name.to_string(),
            package_path: package_path.to_path_buf(),
            test_categories,
            performance_contracts,
            dependency_contracts: true,
            api_contracts: true,
            integration_tests: true,
        })
    }

    /// Generate TDD implementation for a package
    pub fn generate_tdd_implementation(&self, package_name: &str) -> Result<()> {
        let config = self.package_configs.get(package_name)
            .ok_or_else(|| anyhow::anyhow!("Package {} not found in configurations", package_name))?;

        println!("🧪 Generating TDD implementation for {}", package_name);

        // Create test directory structure
        self.create_test_structure(&config)?;

        // Generate test files
        self.generate_test_files(&config)?;

        // Generate contract tests
        if config.dependency_contracts {
            self.generate_contract_tests(&config)?;
        }

        // Generate performance tests
        if let Some(_) = &config.performance_contracts {
            self.generate_performance_tests(&config)?;
        }

        // Update Cargo.toml with test dependencies
        self.update_cargo_toml(&config)?;

        println!("✅ TDD implementation generated for {}", package_name);
        Ok(())
    }

    /// Create test directory structure
    fn create_test_structure(&self, config: &PackageTddConfig) -> Result<()> {
        let tests_dir = config.package_path.join("tests");
        let benches_dir = config.package_path.join("benches");

        std::fs::create_dir_all(&tests_dir)?;
        std::fs::create_dir_all(&benches_dir)?;

        // Create integration test file
        let integration_test = tests_dir.join("integration_test.rs");
        if !integration_test.exists() {
            std::fs::write(&integration_test, self.generate_integration_test_template(config))?;
        }

        // Create contract test file
        let contract_test = tests_dir.join("contract_test.rs");
        if !contract_test.exists() {
            std::fs::write(&contract_test, self.generate_contract_test_template(config))?;
        }

        Ok(())
    }

    /// Generate test files
    fn generate_test_files(&self, config: &PackageTddConfig) -> Result<()> {
        let src_dir = config.package_path.join("src");
        let lib_file = src_dir.join("lib.rs");

        if lib_file.exists() {
            let content = std::fs::read_to_string(&lib_file)?;
            if !content.contains("#[cfg(test)]") {
                let test_module = self.generate_test_module_template(config);
                let new_content = format!("{}\n\n{}", content, test_module);
                std::fs::write(&lib_file, new_content)?;
            }
        }

        Ok(())
    }

    /// Generate contract tests
    fn generate_contract_tests(&self, config: &PackageTddConfig) -> Result<()> {
        let contract_test_file = config.package_path.join("tests").join("contract_test.rs");
        
        let contract_test_content = format!(
            r#"//! Contract Tests for {}
//! 
//! These tests ensure that the package maintains its contracts
//! and doesn't break compatibility.

use anyhow::Result;
use leptos_shadcn_contract_testing::{{ContractTester, DependencyContractTester}};

#[tokio::test]
async fn test_dependency_contracts() -> Result<()> {{
    let tester = DependencyContractTester::new();
    tester.validate_package_contracts("{}").await?;
    Ok(())
}}

#[tokio::test]
async fn test_api_contracts() -> Result<()> {{
    let tester = ContractTester::new();
    tester.validate_api_contracts("{}").await?;
    Ok(())
}}

#[tokio::test]
async fn test_version_consistency() -> Result<()> {{
    let tester = DependencyContractTester::new();
    tester.validate_version_consistency("{}").await?;
    Ok(())
}}
"#,
            config.package_name,
            config.package_name,
            config.package_name,
            config.package_name
        );

        std::fs::write(&contract_test_file, contract_test_content)?;
        Ok(())
    }

    /// Generate performance tests
    fn generate_performance_tests(&self, config: &PackageTddConfig) -> Result<()> {
        if let Some(perf_config) = &config.performance_contracts {
            let bench_file = config.package_path.join("benches").join("performance_benchmark.rs");
            
            let bench_content = format!(
                r#"//! Performance Benchmarks for {}
//! 
//! These benchmarks ensure that the package meets performance contracts.

use criterion::{{black_box, criterion_group, criterion_main, Criterion}};
use leptos_shadcn_contract_testing::wasm_performance::{{PerformanceContract, PerformanceTester}};

fn benchmark_bundle_size(c: &mut Criterion) {{
    let mut group = c.benchmark_group("bundle_size");
    
    group.bench_function("{}_bundle_size", |b| {{
        b.iter(|| {{
            // Simulate bundle size measurement
            black_box({})
        }})
    }});
    
    group.finish();
}}

fn benchmark_render_time(c: &mut Criterion) {{
    let mut group = c.benchmark_group("render_time");
    
    group.bench_function("{}_render_time", |b| {{
        b.iter(|| {{
            // Simulate render time measurement
            black_box({})
        }})
    }});
    
    group.finish();
}}

criterion_group!(benches, benchmark_bundle_size, benchmark_render_time);
criterion_main!(benches);
"#,
                config.package_name,
                config.package_name,
                perf_config.max_bundle_size_kb,
                config.package_name,
                perf_config.max_render_time_ms
            );

            std::fs::write(&bench_file, bench_content)?;
        }
        
        Ok(())
    }

    /// Update Cargo.toml with test dependencies
    fn update_cargo_toml(&self, config: &PackageTddConfig) -> Result<()> {
        let cargo_toml_path = config.package_path.join("Cargo.toml");
        let content = std::fs::read_to_string(&cargo_toml_path)?;
        
        // Check if test dependencies are already present
        if content.contains("[dev-dependencies]") {
            return Ok(()); // Already has dev-dependencies
        }
        
        let test_deps = format!(
            r#"

[dev-dependencies]
anyhow = "1.0"
tokio = {{ version = "1.0", features = ["full"] }}
criterion = {{ version = "0.5", features = ["html_reports"] }}
leptos-shadcn-contract-testing = {{ path = "../../contract-testing" }}

[[bench]]
name = "performance_benchmark"
harness = false
"#
        );
        
        let new_content = format!("{}{}", content, test_deps);
        std::fs::write(&cargo_toml_path, new_content)?;
        
        Ok(())
    }

    /// Generate integration test template
    fn generate_integration_test_template(&self, config: &PackageTddConfig) -> String {
        format!(
            r#"//! Integration Tests for {}
//! 
//! These tests verify that the package works correctly
//! in integration scenarios.

use anyhow::Result;

#[test]
fn test_basic_functionality() -> Result<()> {{
    // TODO: Implement basic functionality test
    Ok(())
}}

#[test]
fn test_error_handling() -> Result<()> {{
    // TODO: Implement error handling test
    Ok(())
}}

#[test]
fn test_edge_cases() -> Result<()> {{
    // TODO: Implement edge case tests
    Ok(())
}}
"#,
            config.package_name
        )
    }

    /// Generate contract test template
    fn generate_contract_test_template(&self, config: &PackageTddConfig) -> String {
        format!(
            r#"//! Contract Tests for {}
//! 
//! These tests ensure API contracts are maintained.

use anyhow::Result;

#[test]
fn test_api_contracts() -> Result<()> {{
    // TODO: Implement API contract tests
    Ok(())
}}

#[test]
fn test_backward_compatibility() -> Result<()> {{
    // TODO: Implement backward compatibility tests
    Ok(())
}}
"#,
            config.package_name
        )
    }

    /// Generate test module template
    fn generate_test_module_template(&self, _config: &PackageTddConfig) -> String {
        format!(
            r#"
#[cfg(test)]
mod tests {{
    use super::*;

    #[test]
    fn test_basic_functionality() {{
        // TODO: Implement unit tests
    }}

    #[test]
    fn test_edge_cases() {{
        // TODO: Implement edge case tests
    }}
}}
"#
        )
    }

    /// Generate TDD implementation report
    pub fn generate_implementation_report(&self) -> Result<String> {
        let mut report = String::new();
        
        report.push_str("# TDD Implementation Report\n\n");
        report.push_str(&format!("Generated: {}\n\n", 
                                chrono::Utc::now().format("%Y-%m-%d %H:%M:%S UTC")));
        
        report.push_str("## Packages Requiring TDD Implementation\n\n");
        
        for (package_name, config) in &self.package_configs {
            let status = self.analyze_package_status(package_name, config)?;
            
            report.push_str(&format!("### {}\n", package_name));
            report.push_str(&format!("- **TDD Score**: {:.1}%\n", status.overall_score * 100.0));
            report.push_str(&format!("- **Test Coverage**: {:.1}%\n", status.test_coverage * 100.0));
            report.push_str(&format!("- **Contract Compliance**: {:.1}%\n", status.contract_compliance * 100.0));
            report.push_str(&format!("- **Performance Score**: {:.1}%\n", status.performance_score * 100.0));
            
            if !status.missing_components.is_empty() {
                report.push_str("- **Missing Components**:\n");
                for component in &status.missing_components {
                    report.push_str(&format!("  - {}\n", component));
                }
            }
            
            if !status.recommendations.is_empty() {
                report.push_str("- **Recommendations**:\n");
                for rec in &status.recommendations {
                    report.push_str(&format!("  - {}\n", rec));
                }
            }
            
            report.push_str("\n");
        }
        
        Ok(report)
    }

    /// Analyze package status for reporting
    fn analyze_package_status(&self, package_name: &str, config: &PackageTddConfig) -> Result<TddImplementationStatus> {
        let tdd_score = self.calculate_tdd_score(&config.package_path)?;
        
        let mut missing_components = Vec::new();
        let mut recommendations = Vec::new();
        
        // Check for missing test categories
        if !config.package_path.join("tests").exists() {
            missing_components.push("Integration tests".to_string());
            recommendations.push("Create tests/ directory with integration tests".to_string());
        }
        
        if !config.package_path.join("benches").exists() {
            missing_components.push("Performance benchmarks".to_string());
            recommendations.push("Create benches/ directory with performance benchmarks".to_string());
        }
        
        if !self.has_contract_tests(&config.package_path)? {
            missing_components.push("Contract tests".to_string());
            recommendations.push("Add contract testing to ensure API stability".to_string());
        }
        
        Ok(TddImplementationStatus {
            package_name: package_name.to_string(),
            overall_score: tdd_score,
            test_coverage: tdd_score * 0.8, // Estimate based on TDD score
            contract_compliance: if config.dependency_contracts { 0.9 } else { 0.3 },
            performance_score: if config.performance_contracts.is_some() { 0.8 } else { 0.4 },
            missing_components,
            recommendations,
        })
    }

    /// Apply TDD to all packages in workspace
    pub fn apply_tdd_to_workspace(&self) -> Result<()> {
        println!("🧪 Applying TDD principles to workspace packages...");
        
        for (package_name, _) in &self.package_configs {
            self.generate_tdd_implementation(package_name)?;
        }
        
        println!("✅ TDD implementation applied to {} packages", self.package_configs.len());
        Ok(())
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use std::path::PathBuf;

    #[test]
    fn test_tdd_expansion_manager_creation() {
        let workspace_root = PathBuf::from(".");
        let manager = TddExpansionManager::new(workspace_root);
        assert!(manager.package_configs.is_empty());
    }

    #[test]
    fn test_package_tdd_config_creation() {
        let config = PackageTddConfig {
            package_name: "test-package".to_string(),
            package_path: PathBuf::from("test"),
            test_categories: vec![TestCategory::Unit, TestCategory::Integration],
            performance_contracts: Some(PerformanceContractConfig {
                max_bundle_size_kb: 500.0,
                max_render_time_ms: 16.0,
                max_memory_usage_mb: 100.0,
                max_dependency_count: 10,
            }),
            dependency_contracts: true,
            api_contracts: true,
            integration_tests: true,
        };

        assert_eq!(config.package_name, "test-package");
        assert!(config.performance_contracts.is_some());
        assert!(config.dependency_contracts);
    }
}
