dissolve-python 0.3.0

// Copyright (C) 2024 Jelmer Vernooij <jelmer@samba.org>
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//    http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

//! Builder patterns for creating complex dissolve operations

use crate::config::Config;
use crate::core::{CollectorResult, ReplaceInfo};
use crate::domain_types::{ModuleName, QualifiedName, Version};
use crate::error::{DissolveError, Result};
use crate::performance::PerformanceMonitor;
use crate::type_introspection_context::TypeIntrospectionContext;
use crate::types::TypeIntrospectionMethod;
use std::collections::HashMap;
use std::path::{Path, PathBuf};

/// Builder for migration operations
pub struct MigrationBuilder {
    config: Config,
    replacements: HashMap<QualifiedName, ReplaceInfo>,
    source_paths: Vec<PathBuf>,
    target_module: Option<ModuleName>,
    performance_monitor: Option<PerformanceMonitor>,
}

impl MigrationBuilder {
    /// Create a new migration builder
    pub fn new() -> Self {
        Self {
            config: Config::default(),
            replacements: HashMap::new(),
            source_paths: Vec::new(),
            target_module: None,
            performance_monitor: None,
        }
    }

    /// Set the configuration
    pub fn with_config(mut self, config: Config) -> Self {
        self.config = config;
        self
    }

    /// Set the type introspection method
    pub fn with_type_introspection(mut self, method: TypeIntrospectionMethod) -> Self {
        self.config.type_introspection = method;
        self
    }

    /// Add source paths to process
    pub fn with_sources<P: AsRef<Path>>(mut self, paths: impl IntoIterator<Item = P>) -> Self {
        self.source_paths
            .extend(paths.into_iter().map(|p| p.as_ref().to_path_buf()));
        self
    }

    /// Add a single source path
    pub fn with_source<P: AsRef<Path>>(mut self, path: P) -> Self {
        self.source_paths.push(path.as_ref().to_path_buf());
        self
    }

    /// Set the target module for replacements
    pub fn with_target_module(mut self, module: ModuleName) -> Self {
        self.target_module = Some(module);
        self
    }

    /// Add replacement info
    pub fn with_replacement(mut self, qualified_name: QualifiedName, info: ReplaceInfo) -> Self {
        self.replacements.insert(qualified_name, info);
        self
    }

    /// Add multiple replacements from a collector result
    pub fn with_replacements_from_collector(mut self, collector_result: CollectorResult) -> Self {
        for (name, info) in collector_result.replacements {
            if let Ok(qualified_name) = QualifiedName::from_string(&name) {
                self.replacements.insert(qualified_name, info);
            }
        }
        self
    }

    /// Enable performance monitoring
    pub fn with_performance_monitoring(mut self, enable: bool) -> Self {
        if enable {
            self.performance_monitor = Some(PerformanceMonitor::new(
                self.config.performance.batch_size,
                1000, // Default type cache size
            ));
        } else {
            self.performance_monitor = None;
        }
        self
    }

    /// Enable writing changes to files
    pub fn write_changes(mut self, write: bool) -> Self {
        self.config.write_changes = write;
        self
    }

    /// Set current version for version-based operations
    pub fn with_current_version(mut self, version: Version) -> Self {
        self.config.current_version = Some(version);
        self
    }

    /// Build and execute the migration
    pub fn execute(self) -> Result<MigrationResult> {
        self.validate()?;

        let mut type_context = TypeIntrospectionContext::new(self.config.type_introspection)
            .map_err(|e| {
                DissolveError::internal(format!("Failed to create type context: {}", e))
            })?;
        let mut results = MigrationResult::new();

        // Process each source path
        for source_path in &self.source_paths {
            if source_path.is_file() {
                let result = self.process_file(source_path, &mut type_context)?;
                results.merge(result);
            } else if source_path.is_dir() {
                let result = self.process_directory(source_path, &mut type_context)?;
                results.merge(result);
            } else {
                return Err(DissolveError::invalid_input(format!(
                    "Path does not exist: {}",
                    source_path.display()
                )));
            }
        }

        type_context.shutdown().map_err(|e| {
            DissolveError::internal(format!("Failed to shutdown type context: {}", e))
        })?;

        // Add performance summary if monitoring was enabled
        if let Some(monitor) = &self.performance_monitor {
            results.performance_summary = Some(monitor.summary());
        }

        Ok(results)
    }

    /// Validate the builder configuration
    fn validate(&self) -> Result<()> {
        if self.source_paths.is_empty() {
            return Err(DissolveError::invalid_input("No source paths specified"));
        }

        if self.replacements.is_empty() {
            return Err(DissolveError::invalid_input("No replacements specified"));
        }

        self.config.validate()?;
        Ok(())
    }

    /// Process a single file
    fn process_file(
        &self,
        file_path: &Path,
        type_context: &mut TypeIntrospectionContext,
    ) -> Result<MigrationResult> {
        let source = std::fs::read_to_string(file_path)?;
        let module_name = self.detect_module_name(file_path)?;

        let start = std::time::Instant::now();

        // Use the migration logic from existing modules
        let replacements_map: HashMap<String, ReplaceInfo> = self
            .replacements
            .iter()
            .map(|(k, v)| (k.to_string(), v.clone()))
            .collect();

        let migrated_source = crate::migrate_stub::migrate_file(
            &source,
            &module_name.to_string(),
            file_path,
            type_context,
            replacements_map,
            HashMap::new(), // Empty unreplaceable map
        )
        .map_err(|e| DissolveError::internal(format!("Migration failed: {}", e)))?;

        let elapsed = start.elapsed();

        if let Some(monitor) = &self.performance_monitor {
            monitor.record_file_processed();
            monitor.record_migration_time(elapsed);
        }

        let mut result = MigrationResult::new();
        result.files_processed.push(FileResult {
            path: file_path.to_path_buf(),
            original_size: source.len(),
            migrated_size: migrated_source.len(),
            processing_time: elapsed,
            changes_made: source != migrated_source,
        });

        if self.config.write_changes && source != migrated_source {
            if self.config.create_backups {
                let backup_path = format!("{}.bak", file_path.display());
                std::fs::copy(file_path, &backup_path)?;
                result.backups_created.push(PathBuf::from(backup_path));
            }

            std::fs::write(file_path, &migrated_source)?;
            result.files_written += 1;
        }

        Ok(result)
    }

    /// Process a directory recursively
    fn process_directory(
        &self,
        dir_path: &Path,
        type_context: &mut TypeIntrospectionContext,
    ) -> Result<MigrationResult> {
        let mut results = MigrationResult::new();

        for entry in walkdir::WalkDir::new(dir_path) {
            let entry = entry.map_err(|e| DissolveError::Io(e.into()))?;
            let path = entry.path();

            if path.is_file() && path.extension().and_then(|s| s.to_str()) == Some("py") {
                // Check if this module should be excluded
                if let Ok(module_name) = self.detect_module_name(path) {
                    if self.config.excluded_modules.contains(&module_name) {
                        continue;
                    }
                }

                let file_result = self.process_file(path, type_context)?;
                results.merge(file_result);
            }
        }

        Ok(results)
    }

    /// Detect module name from file path
    fn detect_module_name(&self, file_path: &Path) -> Result<ModuleName> {
        // Simple implementation - in practice this would be more sophisticated
        let stem = file_path
            .file_stem()
            .and_then(|s| s.to_str())
            .ok_or_else(|| DissolveError::invalid_input("Invalid file path"))?;

        if stem == "__init__" {
            // Use parent directory name
            let parent = file_path
                .parent()
                .and_then(|p| p.file_name())
                .and_then(|n| n.to_str())
                .ok_or_else(|| DissolveError::invalid_input("Cannot determine module name"))?;
            Ok(ModuleName::new(parent))
        } else {
            Ok(ModuleName::new(stem))
        }
    }
}

impl Default for MigrationBuilder {
    fn default() -> Self {
        Self::new()
    }
}

/// Builder for collection operations (finding deprecated functions)
pub struct CollectionBuilder {
    config: Config,
    source_paths: Vec<PathBuf>,
    target_modules: Vec<ModuleName>,
}

impl CollectionBuilder {
    pub fn new() -> Self {
        Self {
            config: Config::default(),
            source_paths: Vec::new(),
            target_modules: Vec::new(),
        }
    }

    pub fn with_config(mut self, config: Config) -> Self {
        self.config = config;
        self
    }

    pub fn with_sources<P: AsRef<Path>>(mut self, paths: impl IntoIterator<Item = P>) -> Self {
        self.source_paths
            .extend(paths.into_iter().map(|p| p.as_ref().to_path_buf()));
        self
    }

    pub fn with_target_modules(mut self, modules: impl IntoIterator<Item = ModuleName>) -> Self {
        self.target_modules.extend(modules);
        self
    }

    pub fn execute(self) -> Result<CollectorResult> {
        self.validate()?;

        let mut all_replacements = HashMap::new();
        let mut all_unreplaceable = HashMap::new();
        let mut all_imports = Vec::new();

        for source_path in &self.source_paths {
            if source_path.is_file() {
                let result = self.collect_from_file(source_path)?;
                all_replacements.extend(result.replacements);
                all_unreplaceable.extend(result.unreplaceable);
                all_imports.extend(result.imports);
            } else if source_path.is_dir() {
                let result = self.collect_from_directory(source_path)?;
                all_replacements.extend(result.replacements);
                all_unreplaceable.extend(result.unreplaceable);
                all_imports.extend(result.imports);
            }
        }

        Ok(CollectorResult {
            replacements: all_replacements,
            unreplaceable: all_unreplaceable,
            imports: all_imports,
            class_methods: HashMap::new(),
            inheritance_map: HashMap::new(),
        })
    }

    fn validate(&self) -> Result<()> {
        if self.source_paths.is_empty() {
            return Err(DissolveError::invalid_input("No source paths specified"));
        }
        Ok(())
    }

    fn collect_from_file(&self, file_path: &Path) -> Result<CollectorResult> {
        let source = std::fs::read_to_string(file_path)?;
        let module_name = self.detect_module_name(file_path)?;

        // Use existing collector
        let collector = crate::stub_collector::RuffDeprecatedFunctionCollector::new(
            module_name.to_string(),
            None,
        );

        collector
            .collect_from_source(source)
            .map_err(|e| DissolveError::internal(format!("Collection failed: {}", e)))
    }

    fn collect_from_directory(&self, dir_path: &Path) -> Result<CollectorResult> {
        let mut all_replacements = HashMap::new();
        let mut all_unreplaceable = HashMap::new();
        let mut all_imports = Vec::new();

        for entry in walkdir::WalkDir::new(dir_path) {
            let entry = entry.map_err(|e| DissolveError::Io(e.into()))?;
            let path = entry.path();

            if path.is_file() && path.extension().and_then(|s| s.to_str()) == Some("py") {
                let result = self.collect_from_file(path)?;
                all_replacements.extend(result.replacements);
                all_unreplaceable.extend(result.unreplaceable);
                all_imports.extend(result.imports);
            }
        }

        Ok(CollectorResult {
            replacements: all_replacements,
            unreplaceable: all_unreplaceable,
            imports: all_imports,
            class_methods: HashMap::new(),
            inheritance_map: HashMap::new(),
        })
    }

    fn detect_module_name(&self, file_path: &Path) -> Result<ModuleName> {
        let stem = file_path
            .file_stem()
            .and_then(|s| s.to_str())
            .ok_or_else(|| DissolveError::invalid_input("Invalid file path"))?;
        Ok(ModuleName::new(stem))
    }
}

impl Default for CollectionBuilder {
    fn default() -> Self {
        Self::new()
    }
}

/// Result of a migration operation
#[derive(Debug)]
pub struct MigrationResult {
    pub files_processed: Vec<FileResult>,
    pub files_written: usize,
    pub backups_created: Vec<PathBuf>,
    pub performance_summary: Option<crate::performance::PerformanceSummary>,
}

impl MigrationResult {
    pub fn new() -> Self {
        Self {
            files_processed: Vec::new(),
            files_written: 0,
            backups_created: Vec::new(),
            performance_summary: None,
        }
    }

    pub fn merge(&mut self, other: MigrationResult) {
        self.files_processed.extend(other.files_processed);
        self.files_written += other.files_written;
        self.backups_created.extend(other.backups_created);
        // Performance summary would be combined differently in a real implementation
    }

    pub fn total_files(&self) -> usize {
        self.files_processed.len()
    }

    pub fn files_with_changes(&self) -> usize {
        self.files_processed
            .iter()
            .filter(|f| f.changes_made)
            .count()
    }

    pub fn total_processing_time(&self) -> std::time::Duration {
        self.files_processed.iter().map(|f| f.processing_time).sum()
    }
}

impl Default for MigrationResult {
    fn default() -> Self {
        Self::new()
    }
}

#[derive(Debug)]
pub struct FileResult {
    pub path: PathBuf,
    pub original_size: usize,
    pub migrated_size: usize,
    pub processing_time: std::time::Duration,
    pub changes_made: bool,
}

impl std::fmt::Display for MigrationResult {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        writeln!(f, "Migration Results:")?;
        writeln!(f, "  Files processed: {}", self.total_files())?;
        writeln!(f, "  Files with changes: {}", self.files_with_changes())?;
        writeln!(f, "  Files written: {}", self.files_written)?;
        writeln!(f, "  Backups created: {}", self.backups_created.len())?;
        writeln!(
            f,
            "  Total processing time: {:.2?}",
            self.total_processing_time()
        )?;

        if let Some(perf) = &self.performance_summary {
            write!(f, "\n{}", perf)?;
        }

        Ok(())
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use tempfile::TempDir;

    #[test]
    fn test_migration_builder() {
        let builder = MigrationBuilder::new()
            .with_type_introspection(TypeIntrospectionMethod::MypyDaemon)
            .write_changes(false)
            .with_performance_monitoring(true);

        // Validation should fail because no sources or replacements
        assert!(builder.validate().is_err());
    }

    #[test]
    fn test_collection_builder() {
        let temp_dir = TempDir::new().unwrap();
        let test_file = temp_dir.path().join("test.py");
        std::fs::write(&test_file, "# empty file").unwrap();

        let builder = CollectionBuilder::new().with_sources(vec![test_file]);

        assert!(builder.validate().is_ok());
    }

    #[test]
    fn test_migration_result_display() {
        let mut result = MigrationResult::new();
        result.files_processed.push(FileResult {
            path: PathBuf::from("test.py"),
            original_size: 100,
            migrated_size: 95,
            processing_time: std::time::Duration::from_millis(10),
            changes_made: true,
        });
        result.files_written = 1;

        let display = format!("{}", result);
        assert!(display.contains("Files processed: 1"));
        assert!(display.contains("Files with changes: 1"));
    }
}