ryo-executor 0.1.0

//! ASTRegApply implementations for AddItemMutation, AddPureItemsMutation, RemoveItemMutation, and MoveItemMutation

use ryo_analysis::AnalysisContext;
use ryo_mutations::{
    AddItemMutation, AddPureItemsMutation, MoveItemMutation, MutationResult, RemoveItemMutation,
};
use ryo_source::pure::{PureFile, PureItem, PureUse, PureUseTree, PureVis};
use ryo_source::ItemKind;
use ryo_symbol::{SymbolKind, SymbolPath, Visibility};

use crate::engine::{ASTMutationContext, ASTRegApply, ExecutionResult};

/// Add an item from raw source code content
pub fn add_item_v2(
    ctx: &mut AnalysisContext,
    target: &SymbolPath,
    content: &str,
) -> ExecutionResult {
    let mut mutation_ctx = ASTMutationContext::new(&mut ctx.ast_registry, &mut ctx.registry);

    let result = add_item_impl(&mut mutation_ctx, target, content);
    let events = mutation_ctx.into_events();

    ExecutionResult::new(result, events)
}

fn add_item_impl(
    ctx: &mut ASTMutationContext,
    target: &SymbolPath,
    content: &str,
) -> MutationResult {
    // Parse the content to get PureItem(s)
    let parsed = match PureFile::from_source(content.trim()) {
        Ok(file) => file,
        Err(e) => {
            return MutationResult {
                mutation_type: "AddItem".to_string(),
                changes: 0,
                description: format!("Failed to parse content: {}", e),
            };
        }
    };

    let items = parsed.items;
    if items.is_empty() {
        return MutationResult {
            mutation_type: "AddItem".to_string(),
            changes: 0,
            description: "No items found in content".to_string(),
        };
    }

    add_pure_items_impl(ctx, target, items, "AddItem")
}

/// Add pre-built PureItems to a module (shared logic for AddItem and AddPureItems)
fn add_pure_items_impl(
    ctx: &mut ASTMutationContext,
    target: &SymbolPath,
    items: Vec<PureItem>,
    mutation_type: &'static str,
) -> MutationResult {
    let mut added = 0;
    let mut descriptions = Vec::new();
    let mut skipped = Vec::new();

    for item in items {
        // For Mod items, we need to preserve visibility for SymbolRegistry
        let mod_visibility = if let PureItem::Mod(m) = &item {
            Some(pure_vis_to_visibility(&m.vis))
        } else {
            None
        };

        let (name, kind) = match &item {
            PureItem::Fn(f) => (f.name.clone(), SymbolKind::Function),
            PureItem::Struct(s) => (s.name.clone(), SymbolKind::Struct),
            PureItem::Enum(e) => (e.name.clone(), SymbolKind::Enum),
            PureItem::Const(c) => (c.name.clone(), SymbolKind::Const),
            PureItem::Static(s) => (s.name.clone(), SymbolKind::Static),
            PureItem::Type(t) => (t.name.clone(), SymbolKind::TypeAlias),
            PureItem::Trait(t) => (t.name.clone(), SymbolKind::Trait),
            PureItem::Mod(m) => (m.name.clone(), SymbolKind::Mod),
            PureItem::Impl(i) => {
                // Use common impl block registration logic
                match super::utils::register_impl_block(ctx, target, i) {
                    Ok(result) => {
                        // Count methods added (impl block itself may be merged)
                        added += result.methods_added;
                        descriptions.push(result.description);
                    }
                    Err(e) => {
                        skipped.push(format!("Impl block for '{}': {}", i.self_ty, e));
                    }
                }
                continue;
            }
            PureItem::Use(u) => {
                // Use statements are added to module_items without symbol registration
                // They don't have a "name" in the symbol registry sense

                // Find the target module ID
                let target_str = target.to_string();
                if let Some(module_id) = ctx.symbol_registry.lookup(target) {
                    // Get current module items and add the use statement at the beginning
                    let mut items = ctx
                        .ast_registry
                        .get_module_items(module_id)
                        .cloned()
                        .unwrap_or_default();

                    // Insert use statement at the beginning (after any existing use statements)
                    let insert_pos = items
                        .iter()
                        .position(|i| !matches!(i, PureItem::Use(_)))
                        .unwrap_or(items.len());
                    items.insert(insert_pos, PureItem::Use(u.clone()));

                    ctx.ast_registry.set_module_items(module_id, items);

                    // Emit event so sync_files_and_rebuild regenerates this module's file
                    ctx.emit_modified(
                        module_id,
                        crate::engine::events::ModificationType::Other(
                            "use statement added".to_string(),
                        ),
                    );

                    added += 1;
                    descriptions.push(format!("Added use statement to '{}'", target_str));
                }
                continue;
            }
            PureItem::Macro(_) | PureItem::Other(_) => {
                // Skip these for now
                continue;
            }
        };

        // Build the full path
        let target_str = target.to_string();
        let full_path = if target_str == "crate" {
            SymbolPath::parse(&format!("crate::{}", name))
        } else {
            SymbolPath::parse(&format!("{}::{}", target_str, name))
        };

        let path = match full_path {
            Ok(p) => p,
            Err(e) => {
                skipped.push(format!(
                    "{} '{}': invalid path ({})",
                    kind.display_name(),
                    name,
                    e
                ));
                continue;
            }
        };

        // Register the new symbol with its AST
        match ctx.register_with_ast(path.clone(), kind, item.clone()) {
            Some(id) => {
                // For Mod items, set visibility in SymbolRegistry
                // This is needed for RegistryGenerator to determine mod visibility
                if let Some(vis) = mod_visibility {
                    let _ = ctx.symbol_registry.set_visibility(id, vis);
                }

                // Mark inline modules: modules with non-empty items should be marked
                // as inline so RegistryGenerator keeps them in the parent file
                // instead of creating separate files for them.
                // This is important for operations like DuplicateModTree.
                if let PureItem::Mod(m) = &item {
                    if !m.items.is_empty() {
                        ctx.ast_registry.mark_inline_module(id);
                    }
                }

                // Also add to parent module's module_items for inline module preservation
                // This ensures RegistryGenerator sees the item in the parent's PureMod.items
                if let Some(parent_id) = ctx.symbol_registry.lookup(target) {
                    let mut items = ctx
                        .ast_registry
                        .get_module_items(parent_id)
                        .cloned()
                        .unwrap_or_default();
                    items.push(item);
                    ctx.ast_registry.set_module_items(parent_id, items);
                }

                added += 1;
                descriptions.push(format!("Added {} '{}'", kind.display_name(), name));
            }
            None => {
                skipped.push(format!(
                    "{} '{}': registration failed (symbol may already exist with different kind)",
                    kind.display_name(),
                    name
                ));
            }
        }
    }

    // Build description with both successes and failures
    let description = match (descriptions.is_empty(), skipped.is_empty()) {
        (true, true) => "No items added".to_string(),
        (true, false) => format!("No items added. Skipped: {}", skipped.join("; ")),
        (false, true) => descriptions.join(", "),
        (false, false) => format!(
            "{}. Skipped: {}",
            descriptions.join(", "),
            skipped.join("; ")
        ),
    };

    MutationResult {
        mutation_type: mutation_type.to_string(),
        changes: added,
        description,
    }
}

/// Remove an item by SymbolId
pub fn remove_item_v2(
    ctx: &mut AnalysisContext,
    symbol_id: ryo_symbol::SymbolId,
    item_kind: &crate::ItemKind,
) -> ExecutionResult {
    let mut mutation_ctx = ASTMutationContext::new(&mut ctx.ast_registry, &mut ctx.registry);

    let result = remove_item_impl(&mut mutation_ctx, symbol_id, item_kind);
    let events = mutation_ctx.into_events();

    ExecutionResult::new(result, events)
}

fn remove_item_impl(
    ctx: &mut ASTMutationContext,
    symbol_id: ryo_symbol::SymbolId,
    item_kind: &crate::ItemKind,
) -> MutationResult {
    // Remove the symbol directly via O(1) lookup
    ctx.remove_symbol(symbol_id);

    MutationResult {
        mutation_type: "RemoveItem".to_string(),
        changes: 1,
        description: format!("Removed {:?} ({:?})", item_kind, symbol_id),
    }
}

// ============================================================================
// ASTRegApply implementations
// ============================================================================

impl ASTRegApply for AddItemMutation {
    fn apply_to_registry(&self, ctx: &mut ASTMutationContext) -> MutationResult {
        // Use the provided symbol_id as the parent module
        let module_id = self.parent;

        // Verify the target is a module
        if ctx.symbol_registry.kind(module_id) != Some(SymbolKind::Mod) {
            return MutationResult {
                mutation_type: "AddItem".to_string(),
                changes: 0,
                description: format!("Target symbol {} is not a module", module_id),
            };
        }

        // Get the module path
        let target = match ctx.symbol_registry.path(module_id) {
            Some(p) => p.clone(),
            None => {
                return MutationResult {
                    mutation_type: "AddItem".to_string(),
                    changes: 0,
                    description: format!("Module {} not found in registry", module_id),
                };
            }
        };

        add_item_impl(ctx, &target, &self.content)
    }
}

impl ASTRegApply for AddPureItemsMutation {
    fn apply_to_registry(&self, ctx: &mut ASTMutationContext) -> MutationResult {
        // Use the provided symbol_id as the parent module
        let module_id = self.parent;

        // Verify the target is a module
        if ctx.symbol_registry.kind(module_id) != Some(SymbolKind::Mod) {
            return MutationResult {
                mutation_type: "AddPureItems".to_string(),
                changes: 0,
                description: format!("Target symbol {} is not a module", module_id),
            };
        }

        // Get the module path
        let target = match ctx.symbol_registry.path(module_id) {
            Some(p) => p.clone(),
            None => {
                return MutationResult {
                    mutation_type: "AddPureItems".to_string(),
                    changes: 0,
                    description: format!("Module {} not found in registry", module_id),
                };
            }
        };

        add_pure_items_impl(ctx, &target, self.items.clone(), "AddPureItems")
    }
}

impl ASTRegApply for RemoveItemMutation {
    fn apply_to_registry(&self, ctx: &mut ASTMutationContext) -> MutationResult {
        remove_item_impl(ctx, self.symbol_id, &self.item_kind)
    }
}

impl ASTRegApply for MoveItemMutation {
    fn apply_to_registry(&self, ctx: &mut ASTMutationContext) -> MutationResult {
        move_item_impl(
            ctx,
            &self.source,
            &self.target,
            &self.item_name,
            &self.item_kind,
            self.add_use,
        )
    }
}

/// Move an item from one module to another
fn move_item_impl(
    ctx: &mut ASTMutationContext,
    source: &SymbolPath,
    target: &SymbolPath,
    item_name: &str,
    item_kind: &ItemKind,
    add_use: bool,
) -> MutationResult {
    // Convert ItemKind to SymbolKind for lookup
    let expected_kind = match item_kind {
        ItemKind::Struct => Some(SymbolKind::Struct),
        ItemKind::Enum => Some(SymbolKind::Enum),
        ItemKind::Function => Some(SymbolKind::Function),
        ItemKind::Trait => Some(SymbolKind::Trait),
        ItemKind::Impl => Some(SymbolKind::Impl),
        ItemKind::TypeAlias => Some(SymbolKind::TypeAlias),
        ItemKind::Const => Some(SymbolKind::Const),
        ItemKind::Static => Some(SymbolKind::Static),
        ItemKind::Mod => Some(SymbolKind::Mod),
        _ => None,
    };

    // 1. Find source symbol by iterating registry (to match kind)
    let source_id = ctx
        .symbol_registry
        .iter()
        .find(|(id, path)| {
            let path_matches = path.name() == item_name && path.parent() == Some(source.clone());
            let kind_matches = expected_kind
                .map(|k| ctx.symbol_registry.kind(*id) == Some(k))
                .unwrap_or(true);
            path_matches && kind_matches
        })
        .map(|(id, _)| id);

    let source_id = match source_id {
        Some(id) => id,
        None => {
            return MutationResult {
                mutation_type: "MoveItem".to_string(),
                changes: 0,
                description: format!("Item '{}' not found in {}", item_name, source),
            };
        }
    };

    // 2. Get AST and kind before removing
    let ast = match ctx.get_ast(source_id).cloned() {
        Some(ast) => ast,
        None => {
            return MutationResult {
                mutation_type: "MoveItem".to_string(),
                changes: 0,
                description: format!("No AST found for '{}'", item_name),
            };
        }
    };
    let kind = ctx.kind(source_id).unwrap_or(SymbolKind::Struct);

    // 3. Remove from old location
    ctx.remove_symbol(source_id);

    // 4. Build target path
    let target_path = match target.child(item_name) {
        Ok(p) => p,
        Err(_) => {
            return MutationResult {
                mutation_type: "MoveItem".to_string(),
                changes: 0,
                description: format!("Invalid target path: {}::{}", target, item_name),
            };
        }
    };

    // 5. Register at new location
    if ctx
        .register_with_ast(target_path.clone(), kind, ast)
        .is_none()
    {
        return MutationResult {
            mutation_type: "MoveItem".to_string(),
            changes: 0,
            description: format!("Failed to register at new path: {}", target_path),
        };
    }

    // 6. Optionally add use statement in source module
    if add_use {
        // Build use path: target::item_name
        let use_path_str = format!("{}::{}", target, item_name);

        // Parse path into PureUseTree
        // e.g., "crate::core::Task" -> Path("crate", Path("core", Name("Task")))
        let parts: Vec<&str> = use_path_str.split("::").collect();
        let tree = parts
            .iter()
            .rev()
            .fold(None, |acc: Option<PureUseTree>, part| {
                Some(match acc {
                    None => PureUseTree::Name(part.to_string()),
                    Some(subtree) => PureUseTree::Path {
                        path: part.to_string(),
                        tree: Box::new(subtree),
                    },
                })
            })
            .unwrap_or(PureUseTree::Name(item_name.to_string()));

        let use_item = PureItem::Use(PureUse {
            vis: PureVis::Private,
            tree,
        });

        // Find source module and add use to its module_items
        if let Some(source_mod_id) = ctx.lookup(source) {
            let mut items = ctx
                .ast_registry
                .get_module_items(source_mod_id)
                .cloned()
                .unwrap_or_default();

            // Insert after existing use statements
            let insert_pos = items
                .iter()
                .position(|i| !matches!(i, PureItem::Use(_)))
                .unwrap_or(items.len());
            items.insert(insert_pos, use_item);

            ctx.ast_registry.set_module_items(source_mod_id, items);
        }
    }

    MutationResult {
        mutation_type: "MoveItem".to_string(),
        changes: 1,
        description: format!(
            "Moved {} '{}' from {} to {}",
            kind.display_name(),
            item_name,
            source,
            target
        ),
    }
}

/// Convert PureVis to ryo_symbol::Visibility
fn pure_vis_to_visibility(vis: &PureVis) -> Visibility {
    match vis {
        PureVis::Public => Visibility::Public,
        PureVis::Crate => Visibility::Crate,
        PureVis::Super => Visibility::Super,
        PureVis::Private => Visibility::Private,
        PureVis::In(path) => {
            // Try to parse as SymbolPath, fallback to Private if invalid
            ryo_symbol::SymbolPath::parse(path)
                .map(|p| Visibility::Restricted(Box::new(p)))
                .unwrap_or(Visibility::Private)
        }
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use ryo_analysis::{ASTRegistry, SymbolRegistry};

    /// Test: Impl block methods are registered directly on parent type
    ///
    /// New design: impl blocks are file-level construct.
    /// Methods are registered as Struct::method, not <impl Struct>::N::method.
    #[test]
    fn test_add_impl_block_registers_methods_on_parent_type() {
        let mut ast_registry = ASTRegistry::new();
        let mut symbol_registry = SymbolRegistry::new();
        let mut ctx = ASTMutationContext::new(&mut ast_registry, &mut symbol_registry);

        // Register the parent struct first
        let struct_path = SymbolPath::parse("test_crate::TodoList").unwrap();
        ctx.register(struct_path.clone(), SymbolKind::Struct);

        let target = SymbolPath::parse("test_crate").unwrap();

        // Add impl block with method
        let impl_code = r#"
            impl TodoList {
                pub fn new() -> Self {
                    Self { items: vec![] }
                }
            }
        "#;
        let result = add_item_impl(&mut ctx, &target, impl_code);
        assert_eq!(result.changes, 1);

        // Verify method is registered as TodoList::new (not <impl TodoList>::N::new)
        let method_path = SymbolPath::parse("test_crate::TodoList::new").unwrap();
        let method_id = ctx.lookup(&method_path);
        assert!(
            method_id.is_some(),
            "Method should be registered as TodoList::new"
        );
        assert_eq!(ctx.kind(method_id.unwrap()), Some(SymbolKind::Method));
    }

    /// Test: Multiple impl blocks merge methods on parent type
    ///
    /// New design: All methods from different impl blocks are registered
    /// under the same parent type path.
    #[test]
    fn test_multiple_impl_blocks_methods_merged() {
        let mut ast_registry = ASTRegistry::new();
        let mut symbol_registry = SymbolRegistry::new();
        let mut ctx = ASTMutationContext::new(&mut ast_registry, &mut symbol_registry);

        // Register the parent struct first
        let struct_path = SymbolPath::parse("test_crate::TodoList").unwrap();
        ctx.register(struct_path.clone(), SymbolKind::Struct);

        let target = SymbolPath::parse("test_crate").unwrap();

        // Add first impl block
        let impl1 = r#"
            impl TodoList {
                pub fn new() -> Self {
                    Self { items: vec![] }
                }
            }
        "#;
        add_item_impl(&mut ctx, &target, impl1);

        // Add second impl block
        let impl2 = r#"
            impl TodoList {
                pub fn add(&mut self, item: String) {
                    self.items.push(item);
                }
            }
        "#;
        add_item_impl(&mut ctx, &target, impl2);

        // Verify both methods are under TodoList::
        let new_path = SymbolPath::parse("test_crate::TodoList::new").unwrap();
        let add_path = SymbolPath::parse("test_crate::TodoList::add").unwrap();

        assert!(
            ctx.lookup(&new_path).is_some(),
            "TodoList::new should exist"
        );
        assert!(
            ctx.lookup(&add_path).is_some(),
            "TodoList::add should exist"
        );

        // Verify both are methods
        assert_eq!(
            ctx.kind(ctx.lookup(&new_path).unwrap()),
            Some(SymbolKind::Method)
        );
        assert_eq!(
            ctx.kind(ctx.lookup(&add_path).unwrap()),
            Some(SymbolKind::Method)
        );
    }
}