eure-tree 0.1.8

use thiserror::Error;

use crate::prelude::*;

#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum NodeTarget {
    CstNodeId(CstNodeId),
    CommandNodeId(CommandNodeId),
}

#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub struct CommandNodeId(usize);

impl From<CommandNodeId> for NodeTarget {
    fn from(value: CommandNodeId) -> Self {
        NodeTarget::CommandNodeId(value)
    }
}

impl From<CstNodeId> for NodeTarget {
    fn from(value: CstNodeId) -> Self {
        NodeTarget::CstNodeId(value)
    }
}

#[derive(Debug, PartialEq, Eq, Clone, Default)]
pub struct CstCommands {
    insert_num: usize,
    commands: Vec<Command>,
}

impl CstCommands {
    pub fn delete_node(&mut self, id: impl Into<NodeTarget>) {
        self.commands.push(Command::DeleteNode(id.into()));
    }

    pub fn delete_recursive(&mut self, id: impl Into<NodeTarget>) {
        self.commands.push(Command::DeleteRecursive(id.into()));
    }

    #[must_use]
    pub fn insert_dynamic_terminal(
        &mut self,
        kind: TerminalKind,
        data: impl Into<String>,
    ) -> CommandNodeId {
        self.commands.push(Command::InsertDynamicTerminal {
            kind,
            data: data.into(),
        });
        let id = CommandNodeId(self.insert_num);
        self.insert_num += 1;
        id
    }

    #[must_use]
    pub fn insert_node(&mut self, data: CstNode) -> CommandNodeId {
        self.commands.push(Command::Insert { data });
        let id = CommandNodeId(self.insert_num);
        self.insert_num += 1;
        id
    }

    pub fn update_node(&mut self, id: impl Into<NodeTarget>, data: CstNode) {
        self.commands.push(Command::Update {
            id: id.into(),
            data,
        });
    }

    pub fn update_children(
        &mut self,
        id: impl Into<NodeTarget>,
        children: impl IntoIterator<Item = impl Into<NodeTarget>>,
    ) {
        self.commands.push(Command::UpdateChildren {
            id: id.into(),
            children: children.into_iter().map(|c| c.into()).collect(),
        });
    }

    /// Add nodes before the target child node
    pub fn add_nodes_before(
        &mut self,
        id: impl Into<NodeTarget>,
        before: impl Into<NodeTarget>,
        data: impl IntoIterator<Item = impl Into<NodeTarget>>,
    ) {
        self.commands.push(Command::AddNodesBefore {
            id: id.into(),
            before: before.into(),
            data: data.into_iter().map(|d| d.into()).collect(),
        });
    }

    /// Add nodes after the target child node
    pub fn add_nodes_after(
        &mut self,
        id: impl Into<NodeTarget>,
        after: impl Into<NodeTarget>,
        data: impl IntoIterator<Item = impl Into<NodeTarget>>,
    ) {
        self.commands.push(Command::AddNodesAfter {
            id: id.into(),
            after: after.into(),
            data: data.into_iter().map(|d| d.into()).collect(),
        });
    }
}

#[derive(Debug, Error)]
pub enum CommandApplyError {
    #[error("before node not found")]
    BeforeNodeNotFound { id: CstNodeId, before: CstNodeId },
}

impl CstCommands {
    pub fn apply_to(self, tree: &mut Cst) -> Result<(), CommandApplyError> {
        let mut inserted = vec![];
        let to_id = |inserted: &[CstNodeId], target: NodeTarget| -> CstNodeId {
            match target {
                NodeTarget::CstNodeId(id) => id,
                NodeTarget::CommandNodeId(id) => inserted[id.0],
            }
        };
        for command in self.commands.into_iter() {
            match command {
                Command::Insert { data } => {
                    let id = tree.add_node(data);
                    inserted.push(id);
                }
                Command::DeleteNode(node_target) => {
                    tree.remove_node(to_id(&inserted, node_target));
                }
                Command::DeleteRecursive(node_target) => {
                    tree.remove_node(to_id(&inserted, node_target));
                }
                Command::ChangeParent { id, parent } => {
                    tree.change_parent(to_id(&inserted, id), to_id(&inserted, parent));
                }
                Command::Update { id, data } => {
                    tree.update_node(to_id(&inserted, id), data);
                }
                Command::UpdateChildren { id, children } => {
                    tree.update_children(
                        to_id(&inserted, id),
                        children.into_iter().map(|c| to_id(&inserted, c)),
                    );
                }
                Command::AddNodesBefore { id, before, data } => {
                    let mut children = tree.children(to_id(&inserted, id)).collect::<Vec<_>>();
                    let Some(before_index) =
                        children.iter().position(|c| to_id(&inserted, before) == *c)
                    else {
                        return Err(CommandApplyError::BeforeNodeNotFound {
                            id: to_id(&inserted, id),
                            before: to_id(&inserted, before),
                        });
                    };
                    children.splice(
                        before_index..before_index,
                        data.into_iter().map(|d| to_id(&inserted, d)),
                    );
                    tree.update_children(to_id(&inserted, id), children);
                }
                Command::AddNodesAfter { id, after, data } => {
                    let mut children = tree.children(to_id(&inserted, id)).collect::<Vec<_>>();
                    let Some(after_index) =
                        children.iter().position(|c| to_id(&inserted, after) == *c)
                    else {
                        return Err(CommandApplyError::BeforeNodeNotFound {
                            id: to_id(&inserted, id),
                            before: to_id(&inserted, after),
                        });
                    };
                    children.splice(
                        (after_index + 1)..(after_index + 1),
                        data.into_iter().map(|d| to_id(&inserted, d)),
                    );
                    tree.update_children(to_id(&inserted, id), children);
                }
                Command::InsertDynamicTerminal { kind, data } => {
                    let token_id = tree.insert_dynamic_terminal(data);
                    let node_id = tree.add_node(CstNode::Terminal {
                        kind,
                        data: TerminalData::Dynamic(token_id),
                    });
                    inserted.push(node_id);
                }
            }
        }
        Ok(())
    }
}

#[derive(Debug, Clone, PartialEq, Eq)]
pub enum Command {
    DeleteNode(NodeTarget),
    DeleteRecursive(NodeTarget),
    ChangeParent {
        id: NodeTarget,
        parent: NodeTarget,
    },
    Insert {
        data: CstNode,
    },
    Update {
        id: NodeTarget,
        data: CstNode,
    },
    UpdateChildren {
        id: NodeTarget,
        children: Vec<NodeTarget>,
    },
    AddNodesBefore {
        id: NodeTarget,
        before: NodeTarget,
        data: Vec<NodeTarget>,
    },
    AddNodesAfter {
        id: NodeTarget,
        after: NodeTarget,
        data: Vec<NodeTarget>,
    },
    InsertDynamicTerminal {
        kind: TerminalKind,
        data: String,
    },
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::node_kind::{NonTerminalKind, TerminalKind};
    use crate::tree::{
        ConcreteSyntaxTree, CstNodeData, CstNodeId, DynamicTokenId, NonTerminalData,
    };
    fn create_test_tree() -> ConcreteSyntaxTree<TerminalKind, NonTerminalKind> {
        let root_data =
            CstNodeData::new_non_terminal(NonTerminalKind::Root, NonTerminalData::Dynamic);
        ConcreteSyntaxTree::new(root_data)
    }

    #[test]
    fn test_delete_node() {
        let mut tree = create_test_tree();
        let root = tree.root();

        // Add a child node
        let node_data =
            CstNodeData::new_non_terminal(NonTerminalKind::Root, NonTerminalData::Dynamic);
        let child = tree.add_node_with_parent(node_data, root);

        let mut commands = CstCommands::default();
        commands.delete_node(child);

        commands.apply_to(&mut tree).unwrap();

        assert!(tree.has_no_children(root));
    }

    #[test]
    fn test_delete_recursive() {
        let mut tree = create_test_tree();
        let root = tree.root();

        // Add a child node
        let node_data =
            CstNodeData::new_non_terminal(NonTerminalKind::Root, NonTerminalData::Dynamic);
        let child = tree.add_node_with_parent(node_data, root);

        // Add a grandchild node
        let grandchild_data =
            CstNodeData::new_non_terminal(NonTerminalKind::Eure, NonTerminalData::Dynamic);
        let _grandchild = tree.add_node_with_parent(grandchild_data, child);

        let mut commands = CstCommands::default();
        commands.delete_node(child);

        commands.apply_to(&mut tree).unwrap();

        let root_children: Vec<_> = tree.children(root).collect();
        assert!(!root_children.contains(&child));

        let mut tree = create_test_tree();
        let root = tree.root();

        // Add a child node again
        let node_data =
            CstNodeData::new_non_terminal(NonTerminalKind::Root, NonTerminalData::Dynamic);
        let child = tree.add_node_with_parent(node_data, root);

        let mut commands = CstCommands::default();
        commands.delete_recursive(child);

        commands.apply_to(&mut tree).unwrap();

        let root_children: Vec<_> = tree.children(root).collect();
        assert!(!root_children.contains(&child));
    }

    #[test]
    fn test_change_parent() {
        let mut tree = create_test_tree();
        let root = tree.root();

        let node_data1 =
            CstNodeData::new_non_terminal(NonTerminalKind::Root, NonTerminalData::Dynamic);
        let child1 = tree.add_node_with_parent(node_data1, root);

        let node_data2 =
            CstNodeData::new_non_terminal(NonTerminalKind::Eure, NonTerminalData::Dynamic);
        let child2 = tree.add_node_with_parent(node_data2, root);

        let grandchild_data =
            CstNodeData::new_non_terminal(NonTerminalKind::Root, NonTerminalData::Dynamic);
        let grandchild = tree.add_node_with_parent(grandchild_data, child1);

        let mut commands = CstCommands::default();
        commands.commands.push(Command::ChangeParent {
            id: grandchild.into(),
            parent: child2.into(),
        });

        commands.apply_to(&mut tree).unwrap();

        let child2_children: Vec<_> = tree.children(child2).collect();
        assert!(child2_children.contains(&grandchild));
    }

    #[test]
    fn test_insert() {
        let mut tree = create_test_tree();
        let root = tree.root();

        let node_data =
            CstNodeData::new_non_terminal(NonTerminalKind::Root, NonTerminalData::Dynamic);

        let mut commands = CstCommands::default();
        let node = commands.insert_node(node_data);
        commands.update_children(root, vec![node]);

        commands.apply_to(&mut tree).unwrap();

        let children: Vec<_> = tree.children(root).collect();
        assert_eq!(children.len(), 1);

        let child_data = tree.node_data(children[0]).unwrap();
        assert!(matches!(
            child_data,
            CstNodeData::NonTerminal {
                kind: NonTerminalKind::Root,
                ..
            }
        ));
    }

    #[test]
    fn test_update() {
        let mut tree = create_test_tree();
        let root = tree.root();

        // Add a child node
        let node_data =
            CstNodeData::new_non_terminal(NonTerminalKind::Root, NonTerminalData::Dynamic);
        let child = tree.add_node_with_parent(node_data, root);

        let new_data =
            CstNodeData::new_non_terminal(NonTerminalKind::Eure, NonTerminalData::Dynamic);

        let mut commands = CstCommands::default();
        commands.update_node(child, new_data);

        commands.apply_to(&mut tree).unwrap();

        let updated_data = tree.node_data(child).unwrap();
        assert!(matches!(
            updated_data,
            CstNodeData::NonTerminal {
                kind: NonTerminalKind::Eure,
                ..
            }
        ));
    }

    #[test]
    fn test_add_nodes_before() {
        let mut tree = create_test_tree();
        let root = tree.root();

        let node_data1 =
            CstNodeData::new_non_terminal(NonTerminalKind::Root, NonTerminalData::Dynamic);
        let child1 = tree.add_node_with_parent(node_data1, root);

        let node_data2 =
            CstNodeData::new_non_terminal(NonTerminalKind::Eure, NonTerminalData::Dynamic);
        let child2 = tree.add_node_with_parent(node_data2, root);

        let node_data3 =
            CstNodeData::new_non_terminal(NonTerminalKind::Section, NonTerminalData::Dynamic);
        let child3 = tree.add_node(node_data3);

        let mut commands = CstCommands::default();
        commands.add_nodes_before(root, child2, vec![child3]);

        commands.apply_to(&mut tree).unwrap();

        let children: Vec<_> = tree.children(root).collect();

        assert_eq!(children.len(), 3);

        assert!(children.contains(&child1));
        assert!(children.contains(&child2));
        assert!(children.contains(&child3));

        assert!(tree.children(root).any(|id| id == child3));
    }

    #[test]
    fn test_insert_dynamic_terminal() {
        let mut tree = create_test_tree();
        let root = tree.root();

        let mut commands = CstCommands::default();
        let token_id = commands.insert_dynamic_terminal(TerminalKind::Text, "test_text");
        commands.update_children(root, vec![token_id]);

        commands.apply_to(&mut tree).unwrap();

        assert_eq!(tree.dynamic_token(DynamicTokenId(0)), Some("test_text"));
    }

    #[test]
    fn test_insert_dynamic_terminal_with_add_nodes_before() {
        let mut tree = create_test_tree();
        let root = tree.root();

        // Add two existing children to have something to insert between
        let node_data1 =
            CstNodeData::new_non_terminal(NonTerminalKind::Root, NonTerminalData::Dynamic);
        let child1 = tree.add_node_with_parent(node_data1, root);

        let node_data2 =
            CstNodeData::new_non_terminal(NonTerminalKind::Eure, NonTerminalData::Dynamic);
        let child2 = tree.add_node_with_parent(node_data2, root);

        // Insert a dynamic terminal between child1 and child2
        let mut commands = CstCommands::default();
        let ws_node_id = commands.insert_dynamic_terminal(TerminalKind::Whitespace, " ");
        commands.add_nodes_before(root, child2, vec![ws_node_id]);

        commands.apply_to(&mut tree).unwrap();

        let children: Vec<_> = tree.children(root).collect();
        assert_eq!(children.len(), 3);

        // Check that the whitespace was inserted between child1 and child2
        let child1_pos = children.iter().position(|&id| id == child1).unwrap();
        let child2_pos = children.iter().position(|&id| id == child2).unwrap();

        // The whitespace should be between child1 and child2
        assert!(child1_pos < child2_pos);

        // Get the whitespace node (should be the one that's not child1 or child2)
        let ws_node = children
            .iter()
            .find(|&&id| id != child1 && id != child2)
            .unwrap();
        let ws_data = tree.node_data(*ws_node).unwrap();

        assert!(matches!(
            ws_data,
            CstNodeData::Terminal {
                kind: TerminalKind::Whitespace,
                data: TerminalData::Dynamic(_),
            }
        ));

        // Check that the dynamic token was stored correctly
        if let CstNodeData::Terminal {
            data: TerminalData::Dynamic(token_id),
            ..
        } = ws_data
        {
            assert_eq!(tree.dynamic_token(token_id), Some(" "));
        }
    }

    #[test]
    fn test_commands_with_errors() {
        let mut tree = create_test_tree();
        let root = tree.root();

        let invalid_node = CstNodeId(999);

        let mut commands = CstCommands::default();
        commands.delete_node(invalid_node);

        assert!(commands.apply_to(&mut tree).is_ok());

        let mut commands = CstCommands::default();
        let node_data =
            CstNodeData::new_non_terminal(NonTerminalKind::Root, NonTerminalData::Dynamic);
        let child = tree.add_node(node_data);
        commands.add_nodes_before(root, invalid_node, vec![child]);

        let result = commands.apply_to(&mut tree);
        assert!(result.is_err());
    }
}