use crate::{
    parser::{self, Annotation, Evaluation, Move, SetupInstr, Size, UnknownProperty},
    Color, Date, GameResult, GameType,
};
use serde::{Deserialize, Serialize};
use nary_tree::{NodeId, NodeMut, NodeRef, Tree};
use std::{
    collections::{HashMap, HashSet, VecDeque},
    fmt,
    fmt::Debug,
    ops::{Deref, DerefMut},
    time::Duration,
};
use uuid::Uuid;

#[derive(Clone, Debug, PartialEq)]
pub enum GameError {
    InvalidGame,
    RequiredPropertiesMissing,
    InvalidGameNode(GameNodeError),
}

#[derive(Clone, Debug, PartialEq)]
pub enum MoveNodeError {
    IncompatibleProperty(parser::Property),
    ConflictingProperty,
    NotAMoveNode,
    ChildError(Box<GameNodeError>),
}

#[derive(Clone, Debug, PartialEq)]
pub enum SetupNodeError {
    IncompatibleProperty(parser::Property),
    ConflictingProperty,
    ConflictingPosition,
    NotASetupNode,
    ChildError(Box<GameNodeError>),
}

#[derive(Clone, Debug, PartialEq)]
pub enum GameNodeError {
    UnsupportedGameNode(MoveNodeError, SetupNodeError, parser::Node),
    ConflictingProperty,
    ConflictingPosition,
}

#[derive(Clone, Debug, PartialEq, Default, Deserialize, Serialize)]
pub struct Player {
    pub name: Option<String>,
    pub rank: Option<String>,
    pub team: Option<String>,
}

/// This represents the more semantic version of the game parser. Where the `parser` crate pulls
/// out a raw set of nodes, this structure is guaranteed to be a well-formed game. Getting to this
/// level, the interpreter will reject any games that have setup properties and move properties
/// mixed in a single node. If there are other semantic problems, the interpreter will reject
/// those, as well. Where the function of the parser is to understand and correct fundamental
/// syntax issues, the result of the GameRecord is to have a fully-understood game. However, this
/// doesn't (yet?) go quite to the level of apply the game type (i.e., this is Go, Chess, Yinsh, or
/// whatever).
#[derive(Clone, Debug, PartialEq)]
pub struct GameRecord {
    pub game_type: GameType,

    // TODO: board size is not necessary in all games. Hive has no defined board size.
    pub board_size: Size,
    pub black_player: Player,
    pub white_player: Player,

    pub app: Option<String>,
    pub annotator: Option<String>,
    pub copyright: Option<String>,
    pub dates: Vec<Date>,
    pub event: Option<String>,
    pub game_name: Option<String>,
    pub extra_info: Option<String>,
    pub opening_info: Option<String>,
    pub location: Option<String>,
    pub result: Option<GameResult>,
    pub round: Option<String>,
    pub rules: Option<String>,
    pub source: Option<String>,
    pub time_limit: Option<Duration>,
    pub overtime: Option<String>,
    pub transcriber: Option<String>,

    pub trees: Vec<GameTree>,
}

impl GameRecord {
    pub fn new(
        game_type: GameType,
        board_size: Size,
        black_player: Player,
        white_player: Player,
    ) -> Self {
        Self {
            game_type,
            board_size,
            black_player,
            white_player,

            app: None,
            annotator: None,
            copyright: None,
            dates: vec![],
            event: None,
            game_name: None,
            extra_info: None,
            opening_info: None,
            location: None,
            result: None,
            round: None,
            rules: None,
            source: None,
            time_limit: None,
            overtime: None,
            transcriber: None,

            trees: vec![],
        }
    }

    pub fn nodes(&self) -> Vec<&GameNode> {
        self.iter().collect()
    }

    pub fn iter(&self) -> impl Iterator<Item = &'_ GameNode> {
        self.trees
            .iter()
            .flat_map(|tree| tree.root().unwrap().traverse_pre_order())
            .map(|nr| nr.data())
    }

    /// Generate a list of moves which constitute the main line of the game. This is the game as it
    /// was actually played out, and by convention consists of the first node in each list of
    /// children.
    pub fn mainline(&self) -> Option<impl Iterator<Item = &'_ GameNode>> {
        if !self.trees.is_empty() {
            Some(MainlineIter {
                next: self.trees[0].root(),
                tree: &self.trees[0],
            })
        } else {
            None
        }
    }
}

impl TryFrom<parser::Tree> for GameRecord {
    type Error = GameError;

    fn try_from(tree: parser::Tree) -> Result<Self, Self::Error> {
        let mut ty = None;
        let mut size = None;
        let mut black_player = Player {
            name: None,
            rank: None,
            team: None,
        };
        let mut white_player = Player {
            name: None,
            rank: None,
            team: None,
        };

        for prop in tree.root.properties.iter() {
            match prop {
                parser::Property::GameType(ty_) => ty = Some(ty_.clone()),
                parser::Property::BoardSize(size_) => size = Some(size_.clone()),
                parser::Property::BlackPlayer(name) => {
                    black_player.name = Some(name.clone());
                }
                parser::Property::WhitePlayer(name) => {
                    white_player.name = Some(name.clone());
                }
                parser::Property::BlackRank(rank) => {
                    black_player.rank = Some(rank.clone());
                }
                parser::Property::WhiteRank(rank) => {
                    white_player.rank = Some(rank.clone());
                }
                parser::Property::BlackTeam(team) => {
                    black_player.team = Some(team.clone());
                }
                parser::Property::WhiteTeam(team) => {
                    white_player.team = Some(team.clone());
                }
                _ => {}
            }
        }

        let mut s = match (ty, size) {
            (Some(ty), Some(size)) => Ok(Self::new(ty, size, black_player, white_player)),
            _ => Err(Self::Error::RequiredPropertiesMissing),
        }?;

        for prop in tree.root.properties.iter() {
            match prop {
                parser::Property::GameType(_)
                | parser::Property::BoardSize(_)
                | parser::Property::BlackPlayer(_)
                | parser::Property::WhitePlayer(_)
                | parser::Property::BlackRank(_)
                | parser::Property::WhiteRank(_)
                | parser::Property::BlackTeam(_)
                | parser::Property::WhiteTeam(_) => {}
                parser::Property::Application(v) => s.app = Some(v.clone()),
                parser::Property::Annotator(v) => s.annotator = Some(v.clone()),
                parser::Property::Copyright(v) => s.copyright = Some(v.clone()),
                parser::Property::EventDates(v) => s.dates = v.clone(),
                parser::Property::EventName(v) => s.event = Some(v.clone()),
                parser::Property::GameName(v) => s.game_name = Some(v.clone()),
                parser::Property::ExtraGameInformation(v) => s.extra_info = Some(v.clone()),
                parser::Property::GameOpening(v) => s.opening_info = Some(v.clone()),
                parser::Property::GameLocation(v) => s.location = Some(v.clone()),
                parser::Property::Result(v) => s.result = Some(v.clone()),
                parser::Property::Round(v) => s.round = Some(v.clone()),
                parser::Property::Ruleset(v) => s.rules = Some(v.clone()),
                parser::Property::Source(v) => s.source = Some(v.clone()),
                parser::Property::TimeLimit(v) => s.time_limit = Some(*v),
                parser::Property::Overtime(v) => s.overtime = Some(v.clone()),
                // parser::Property::Data(v) => s.transcriber = Some(v.clone()),
                _ => {}
            }
        }

        /*
        s.children = tree
            .root
            .next
            .iter()
            .map(GameNode::try_from)
            .collect::<Result<Vec<GameNode>, GameNodeError>>()
            .map_err(GameError::InvalidGameNode)?;
            */

        s.trees = tree
            .root
            .next
            .into_iter()
            .map(recursive_tree_to_slab_tree)
            .collect::<Result<Vec<GameTree>, GameError>>()?;

        Ok(s)
    }
}

fn recursive_tree_to_slab_tree(node: parser::Node) -> Result<GameTree, GameError> {
    let mut slab = Tree::new();
    let mut nodes: VecDeque<(NodeId, parser::Node)> = VecDeque::new();

    let root_id =
        slab.set_root(GameNode::try_from(node.clone()).map_err(GameError::InvalidGameNode)?);
    nodes.push_back((root_id, node));

    // I need to keep track of the current parent, and I need to keep on digging deeper into the
    // tree. Given that I have the root, I can then easily find out all of the children.
    //
    // So, maybe I take the list of children. Assign each one of them to a place in the slab tree.
    // Then push the child *and* its ID into a dequeue. So long as the dequeue is not empty, I want
    // to pop a node and its ID from the dequeue. The retrieve the NodeMut for it and work on the
    // node's children.
    while let Some((node_id, node)) = nodes.pop_front() {
        let mut game_node: NodeMut<GameNode> = slab
            .get_mut(node_id)
            .expect("invalid node_id when retrieving nodes from the game");
        // I have a node that is in the tree. Now run across all of its children, adding each one
        // to the tree and pushing them into the deque along with their IDs.
        for child in node.next {
            let slab_child = game_node
                .append(GameNode::try_from(child.clone()).map_err(GameError::InvalidGameNode)?);
            nodes.push_back((slab_child.node_id(), child));
        }
    }

    Ok(GameTree(slab))
}

#[derive(Default)]
pub struct TreeIter<'a> {
    queue: VecDeque<NodeRef<'a, &'a GameNode>>,
}

/*
impl<'a> Default for TreeIter<'a> {
    fn default() -> Self {
        TreeIter {
            queue: VecDeque::default(),
        }
    }
}
*/

impl<'a> Iterator for TreeIter<'a> {
    type Item = &'a GameNode;

    fn next(&mut self) -> Option<Self::Item> {
        let retval = self.queue.pop_front();
        if let Some(ref retval) = retval {
            retval
                .children()
                .for_each(|node| self.queue.push_back(node));
        }
        retval.map(|rv| *rv.data())
    }
}

pub struct GameTree(Tree<GameNode>);

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

impl Clone for GameTree {
    fn clone(&self) -> Self {
        match self.0.root() {
            None => Self(Tree::new()),
            Some(source_root_node) => {
                let mut dest = Tree::new();
                let dest_root_id = dest.set_root(source_root_node.data().clone());

                // In order to add a node to the new tree, I need to know the ID of the parent in
                // the source tree and the ID of the parent in the destination tree. So I want a
                // lookup table that maps source IDs to destination IDs. But is that sufficient?
                // Perhaps I can just keep a mapping from a source noderef to a destination ID.
                // I don't think I can keep more than one mutable destination node.

                let mut mapping: HashMap<NodeId, NodeId> = HashMap::new();
                mapping.insert(source_root_node.node_id(), dest_root_id);

                for source_node in source_root_node.traverse_level_order() {
                    match source_node.parent() {
                        None => {}
                        Some(parent) => {
                            let source_node_parent_id = parent.node_id();
                            let target_node_parent_id = mapping.get(&source_node_parent_id).expect("node should have been added to the source to dest mapping when being cloned");

                            let mut parent = dest.get_mut(*target_node_parent_id).expect(
                        "destination parent node to exist before reaching potential children",
                    );
                            let dest_id = parent.append(source_node.data().clone()).node_id();
                            mapping.insert(source_node.node_id(), dest_id);
                        }
                    }
                }

                Self(dest)
            }
        }
    }
}

impl Debug for GameTree {
    fn fmt(&self, f: &mut std::fmt::Formatter) -> Result<(), std::fmt::Error> {
        self.write_formatted(f)
    }
}

impl Deref for GameTree {
    type Target = Tree<GameNode>;

    fn deref(&self) -> &Self::Target {
        &self.0
    }
}

impl DerefMut for GameTree {
    fn deref_mut(&mut self) -> &mut Self::Target {
        &mut self.0
    }
}

impl PartialEq for GameTree {
    fn eq(&self, other: &Self) -> bool {
        // Get pre-order iterators over both trees, zip them, and ensure that the data contents are
        // the same between them
        let left_root = self.root();
        let right_root = other.root();

        match (left_root, right_root) {
            (Some(left_root), Some(right_root)) => {
                for (left_node, right_node) in std::iter::zip(
                    left_root.traverse_pre_order(),
                    right_root.traverse_pre_order(),
                ) {
                    if left_node.data() != right_node.data() {
                        return false;
                    }
                }
            }
            (None, None) => return true,
            _ => return false,
        }
        true
    }
}

pub struct MainlineIter<'a> {
    next: Option<NodeRef<'a, GameNode>>,
    tree: &'a Tree<GameNode>,
}

impl<'a> Iterator for MainlineIter<'a> {
    type Item = &'a GameNode;

    fn next(&mut self) -> Option<Self::Item> {
        if let Some(next) = self.next.take() {
            let ret = self.tree.get(next.node_id())?;
            self.next = next
                .first_child()
                .and_then(|child| self.tree.get(child.node_id()));
            Some(ret.data())
        } else {
            None
        }
    }
}

#[derive(Clone, Debug, PartialEq, Deserialize, Serialize)]
pub enum GameNode {
    MoveNode(MoveNode),
    SetupNode(SetupNode),
}

impl fmt::Display for GameNode {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
        match self {
            GameNode::MoveNode(_) => write!(f, "MoveNode"),
            GameNode::SetupNode(_) => write!(f, "SetupNode"),
        }
    }
}

impl GameNode {
    pub fn id(&self) -> Uuid {
        match self {
            GameNode::MoveNode(node) => node.id,
            GameNode::SetupNode(node) => node.id,
        }
    }
}

impl TryFrom<parser::Node> for GameNode {
    type Error = GameNodeError;

    fn try_from(n: parser::Node) -> Result<Self, Self::Error> {
        let move_node = MoveNode::try_from(n.clone());
        let setup_node = SetupNode::try_from(n.clone());

        match (move_node, setup_node) {
            (Ok(node), _) => Ok(Self::MoveNode(node)),
            (Err(_), Ok(node)) => Ok(Self::SetupNode(node)),
            (Err(move_err), Err(setup_err)) => {
                Err(Self::Error::UnsupportedGameNode(move_err, setup_err, n))
            }
        }
    }
}

#[derive(Clone, Debug, PartialEq, Deserialize, Serialize)]
pub struct MoveNode {
    pub id: Uuid,
    pub color: Color,
    pub mv: Move,

    pub time_left: Option<Duration>,
    pub moves_left: Option<usize>,
    pub name: Option<String>,
    pub evaluation: Option<Evaluation>,
    pub value: Option<f64>,
    pub comments: Option<String>,
    pub annotation: Option<Annotation>,
    pub unknown_props: Vec<(String, String)>,
}

impl MoveNode {
    pub fn new(color: Color, mv: Move) -> Self {
        Self {
            id: Uuid::new_v4(),
            color,
            mv,

            time_left: None,
            moves_left: None,
            name: None,
            evaluation: None,
            value: None,
            comments: None,
            annotation: None,
            unknown_props: vec![],
        }
    }
}

impl TryFrom<parser::Node> for MoveNode {
    type Error = MoveNodeError;

    fn try_from(n: parser::Node) -> Result<Self, Self::Error> {
        let s = match n.mv() {
            Some((color, mv)) => {
                let mut s = Self::new(color, mv);

                for prop in n.properties.iter() {
                    match prop {
                        parser::Property::Move((color, mv)) => {
                            if s.color != *color || s.mv != *mv {
                                return Err(Self::Error::ConflictingProperty);
                            }
                        }
                        parser::Property::TimeLeft((color, duration)) => {
                            if s.color != *color {
                                return Err(Self::Error::ConflictingProperty);
                            }
                            if s.time_left.is_some() {
                                return Err(Self::Error::ConflictingProperty);
                            }
                            s.time_left = Some(*duration);
                        }
                        parser::Property::Comment(cmt) => {
                            if s.comments.is_some() {
                                return Err(Self::Error::ConflictingProperty);
                            }
                            s.comments = Some(cmt.clone());
                        }
                        parser::Property::Evaluation(evaluation) => {
                            if s.evaluation.is_some() {
                                return Err(Self::Error::ConflictingProperty);
                            }
                            s.evaluation = Some(*evaluation)
                        }
                        parser::Property::Annotation(annotation) => {
                            if s.annotation.is_some() {
                                return Err(Self::Error::ConflictingProperty);
                            }
                            s.annotation = Some(*annotation)
                        }
                        parser::Property::Territory(..) => {
                            eprintln!("not processing territory property");
                        }
                        parser::Property::Unknown(UnknownProperty { ident, value }) => {
                            s.unknown_props.push((ident.clone(), value.clone()));
                        }
                        _ => return Err(Self::Error::IncompatibleProperty(prop.clone())),
                    }
                }

                Ok(s)
            }
            None => Err(Self::Error::NotAMoveNode),
        }?;

        Ok(s)
    }
}

#[derive(Clone, Debug, PartialEq, Deserialize, Serialize)]
pub struct SetupNode {
    id: Uuid,

    pub positions: Vec<parser::SetupInstr>,
}

impl SetupNode {
    pub fn new(positions: Vec<parser::SetupInstr>) -> Result<Self, SetupNodeError> {
        let mut board = HashSet::new();
        for position in positions.iter() {
            let point = match position {
                SetupInstr::Piece((_, point)) => point,
                SetupInstr::Clear(point) => point,
            };
            if board.contains(point) {
                return Err(SetupNodeError::ConflictingPosition);
            }
            board.insert(point);
        }

        Ok(Self {
            id: Uuid::new_v4(),
            positions,
        })
    }
}

impl TryFrom<parser::Node> for SetupNode {
    type Error = SetupNodeError;

    fn try_from(n: parser::Node) -> Result<Self, Self::Error> {
        match n.setup() {
            Some(elements) => Self::new(elements),
            None => Err(Self::Error::NotASetupNode),
        }
    }
}

/*
#[allow(dead_code)]
pub fn path_to_node(node: &GameNode, id: Uuid) -> Vec<&GameNode> {
    if node.id() == id {
        return vec![node];
    }

    for child in node.children() {
        let mut path = path_to_node(child, id);
        if path.len() > 1 {
            path.push(child);
            return path;
        }
    }

    Vec::new()
}
*/

#[cfg(test)]
mod test {
    use super::*;
    use cool_asserts::assert_matches;

    #[test]
    fn it_can_create_an_empty_game_tree() {
        let tree = GameRecord::new(
            GameType::Go,
            Size {
                width: 19,
                height: 19,
            },
            Player::default(),
            Player::default(),
        );
        assert_eq!(tree.nodes().len(), 0);
    }

    #[test]
    fn it_can_add_moves_to_a_game() {
        let mut game = GameRecord::new(
            GameType::Go,
            Size {
                width: 19,
                height: 19,
            },
            Player::default(),
            Player::default(),
        );

        /*
        let first_move = MoveNode::new(Color::Black, Move::Move("dd".to_owned()));
        let first_ = game.add_child(GameNode::MoveNode(first_move.clone()));
        let second_move = MoveNode::new(Color::White, Move::Move("qq".to_owned()));
        first_.add_child(GameNode::MoveNode(second_move.clone()));
        */

        /*
        let nodes = game.nodes();
        assert_eq!(nodes.len(), 2);
        assert_eq!(nodes[0].id(), first_move.id);
        assert_eq!(nodes[1].id(), second_move.id);
        */
    }

    #[ignore]
    #[test]
    fn it_can_set_up_a_game() {
        unimplemented!()
    }

    #[ignore]
    #[test]
    fn it_can_load_tree_from_sgf() {
        unimplemented!()
    }

    #[test]
    fn game_node_can_parse_sgf_move_node() {
        let n = parser::Node {
            properties: vec![
                parser::Property::Move((Color::White, Move::Move("dp".to_owned()))),
                parser::Property::TimeLeft((Color::White, Duration::from_secs(176))),
                parser::Property::Comment("Comments in the game".to_owned()),
            ],
            next: vec![],
        };
        assert_matches!(GameNode::try_from(n), Ok(GameNode::MoveNode(_)));
    }
}

#[cfg(test)]
mod root_node_tests {
    #[ignore]
    #[test]
    fn it_rejects_move_properties() {
        unimplemented!()
    }

    #[ignore]
    #[test]
    fn it_rejects_setup_properties() {
        unimplemented!()
    }

    #[ignore]
    #[test]
    fn it_can_parse_a_root_sgf() {
        unimplemented!()
    }
}

#[cfg(test)]
mod move_node_tests {
    use crate::parser::PositionList;

    use super::*;
    use cool_asserts::assert_matches;

    #[test]
    fn it_can_parse_an_sgf_move_node() {
        let n = parser::Node {
            properties: vec![
                parser::Property::Move((Color::White, Move::Move("dp".to_owned()))),
                parser::Property::TimeLeft((Color::White, Duration::from_secs(176))),
                parser::Property::Comment("Comments in the game".to_owned()),
            ],
            next: vec![],
        };
        assert_matches!(MoveNode::try_from(n), Ok(node) => {
            assert_eq!(node.color, Color::White);
            assert_eq!(node.mv, Move::Move("dp".to_owned()));
            // assert_eq!(node.children, vec![]);
            assert_eq!(node.time_left, Some(Duration::from_secs(176)));
            assert_eq!(node.comments, Some("Comments in the game".to_owned()));
        });
    }

    #[test]
    fn it_rejects_an_sgf_setup_node() {
        let n = parser::Node {
            properties: vec![
                parser::Property::Move((Color::White, Move::Move("dp".to_owned()))),
                parser::Property::TimeLeft((Color::White, Duration::from_secs(176))),
                parser::Property::SetupBlackStones(PositionList(vec![
                    "dd".to_owned(),
                    "de".to_owned(),
                ])),
            ],
            next: vec![],
        };
        assert_matches!(
            MoveNode::try_from(n),
            Err(MoveNodeError::IncompatibleProperty(_))
        );
    }
}

#[cfg(test)]
mod setup_node_tests {
    use crate::parser::SetupInstr;

    use super::*;
    use cool_asserts::assert_matches;

    #[ignore]
    #[test]
    fn it_can_parse_an_sgf_setup_node() {
        unimplemented!()
    }

    #[test]
    fn it_rejects_conflicting_placement_properties() {
        assert_matches!(
            SetupNode::new(vec![
                SetupInstr::Piece((Color::Black, "dd".to_owned())),
                SetupInstr::Piece((Color::Black, "dd".to_owned())),
            ]),
            Err(SetupNodeError::ConflictingPosition)
        );
        assert_matches!(
            SetupNode::new(vec![
                SetupInstr::Piece((Color::Black, "dd".to_owned())),
                SetupInstr::Piece((Color::Black, "ee".to_owned())),
                SetupInstr::Piece((Color::White, "ee".to_owned())),
            ]),
            Err(SetupNodeError::ConflictingPosition)
        );
    }
}

#[cfg(test)]
mod path_test {
    use super::*;
    use cool_asserts::assert_matches;
    use parser::parse_collection;
    use std::{fs::File, io::Read};

    fn with_text(text: &str, f: impl FnOnce(Vec<GameRecord>)) {
        let (_, games) = parse_collection::<nom::error::VerboseError<&str>>(text).unwrap();
        let games = games
            .into_iter()
            .map(|game| GameRecord::try_from(game).expect("game to parse"))
            .collect::<Vec<GameRecord>>();
        f(games);
    }

    fn with_file(path: &std::path::Path, f: impl FnOnce(Vec<GameRecord>)) {
        let mut file = File::open(path).unwrap();
        let mut text = String::new();
        let _ = file.read_to_string(&mut text);
        with_text(&text, f);
    }

    #[test]
    fn returns_the_mainline_of_a_game_without_branches() {
        with_file(
            std::path::Path::new("test_data/2020 USGO DDK, Round 1.sgf"),
            |games| {
                let game = &games[0];

                let moves = game
                    .mainline()
                    .expect("there should be a mainline in this file")
                    .collect::<Vec<&GameNode>>();
                assert_matches!(moves[0], GameNode::MoveNode(node) => {
                    assert_eq!(node.color, Color::Black);
                    assert_eq!(node.mv, Move::Move("pp".to_owned()));
                });
                assert_matches!(moves[1], GameNode::MoveNode(node) => {
                    assert_eq!(node.color, Color::White);
                    assert_eq!(node.mv, Move::Move("dp".to_owned()));
                });
                assert_matches!(moves[2], GameNode::MoveNode(node) => {
                    assert_eq!(node.color, Color::Black);
                    assert_eq!(node.mv, Move::Move("pd".to_owned()));
                });
            },
        )
    }

    #[test]
    fn returns_the_mainline_of_a_game_with_branches() {
        with_file(std::path::Path::new("test_data/branch_test.sgf"), |games| {
            let game = &games[0];

            let moves = game
                .mainline()
                .expect("there should be a mainline in this file")
                .collect::<Vec<&GameNode>>();
            assert_matches!(moves[1], GameNode::MoveNode(node) => {
                assert_eq!(node.color, Color::White);
                assert_eq!(node.mv, Move::Move("dd".to_owned()));
            });
            assert_matches!(moves[2], GameNode::MoveNode(node) => {
                assert_eq!(node.color, Color::Black);
                assert_eq!(node.mv, Move::Move("op".to_owned()));
            });
            assert_matches!(moves[3], GameNode::MoveNode(node) => {
                assert_eq!(node.color, Color::White);
                assert_eq!(node.mv, Move::Move("dp".to_owned()));
            });
        });
    }

    #[ignore]
    #[test]
    fn returns_empty_list_if_no_game_nodes() {
        unimplemented!()
    }

    #[ignore]
    #[test]
    fn returns_empty_list_if_node_not_found() {
        unimplemented!()
    }

    #[ignore]
    #[test]
    fn path_excludes_root_node() {
        unimplemented!()
    }
}

#[cfg(test)]
mod file_test {
    use super::*;
    use crate::Win;
    use cool_asserts::assert_matches;
    use parser::parse_collection;
    use std::{fs::File, io::Read};

    fn with_text(text: &str, f: impl FnOnce(Vec<GameRecord>)) {
        let (_, games) = parse_collection::<nom::error::VerboseError<&str>>(text).unwrap();
        let games = games
            .into_iter()
            .map(|game| GameRecord::try_from(game).expect("game to parse"))
            .collect::<Vec<GameRecord>>();
        f(games);
    }

    fn with_file(path: &std::path::Path, f: impl FnOnce(Vec<GameRecord>)) {
        let mut file = File::open(path).unwrap();
        let mut text = String::new();
        let _ = file.read_to_string(&mut text);
        with_text(&text, f);
    }

    /// This test checks against an ordinary game from SGF. It is unannotated and should contain
    /// only move nodes with no setup nodes. The original source is from a game I played on KGS.
    #[test]
    fn it_can_load_an_ordinary_unannotated_game() {
        with_file(
            std::path::Path::new("test_data/2020 USGO DDK, Round 1.sgf"),
            |games| {
                assert_eq!(games.len(), 1);
                let game = &games[0];

                assert_eq!(game.game_type, GameType::Go);
                assert_eq!(
                    game.board_size,
                    Size {
                        width: 19,
                        height: 19
                    }
                );
                assert_eq!(
                    game.black_player,
                    Player {
                        name: Some("savanni".to_owned()),
                        rank: Some("23k".to_owned()),
                        team: None
                    }
                );
                assert_eq!(
                    game.white_player,
                    Player {
                        name: Some("Geckoz".to_owned()),
                        rank: None,
                        team: None
                    }
                );
                assert_eq!(game.app, Some("CGoban:3".to_owned()));

                assert_eq!(game.annotator, None);
                assert_eq!(game.copyright, None);
                assert_eq!(
                    game.dates,
                    vec![Date::Date(
                        chrono::NaiveDate::from_ymd_opt(2020, 8, 5).unwrap()
                    )]
                );
                assert_eq!(game.event, None);
                assert_eq!(game.game_name, None);
                assert_eq!(game.extra_info, None);
                assert_eq!(game.opening_info, None);
                assert_eq!(
                    game.location,
                    Some("The KGS Go Server at http://www.gokgs.com/".to_owned())
                );
                assert_eq!(game.result, Some(GameResult::White(Win::Score(17.5))));
                assert_eq!(game.round, None);
                assert_eq!(game.rules, Some("AGA".to_owned()));
                assert_eq!(game.source, None);
                assert_eq!(game.time_limit, Some(Duration::from_secs(1800)));
                assert_eq!(game.overtime, Some("5x30 byo-yomi".to_owned()));
                assert_eq!(game.transcriber, None);

                /*
                    Property {
                        ident: "KM".to_owned(),
                        values: vec!["7.50".to_owned()],
                    },
                ];

                for i in 0..16 {
                    assert_eq!(node.properties[i], expected_properties[i]);
                }
                */

                /*
                let children = game.children();
                let node = children.first().unwrap();
                assert_matches!(node, GameNode::MoveNode(node) => {
                    assert_eq!(node.color, Color::Black);
                    assert_eq!(node.mv, Move::Move("pp".to_owned()));
                    assert_eq!(node.time_left, Some(Duration::from_secs(1795)));
                    assert_eq!(node.comments, Some("Geckoz [?]: Good game\nsavanni [23k?]: There we go! This UI is... tough.\nsavanni [23k?]: Have fun! Talk to you at the end.\nGeckoz [?]: Yeah, OGS is much better; I'm a UX professional\n".to_owned())
                )});

                let children = node.children();
                let node = children.first().unwrap();
                assert_matches!(node, GameNode::MoveNode(node) => {
                    assert_eq!(node.color, Color::White);
                    assert_eq!(node.mv, Move::Move("dp".to_owned()));
                    assert_eq!(node.time_left, Some(Duration::from_secs(1765)));
                    assert_eq!(node.comments, None);
                });
                */
                /*
                let node = node.next().unwrap();
                let expected_properties = vec![
                    Property {
                        ident: "W".to_owned(),
                        values: vec!["dp".to_owned()],
                    },
                    Property {
                        ident: "WL".to_owned(),
                        values: vec!["1765.099".to_owned()],
                    },
                ];
                for i in 0..2 {
                    assert_eq!(node.properties[i], expected_properties[i]);
                }
                */
            },
        );
    }

    #[test]
    fn it_can_load_a_file_with_multiple_roots() {
        with_file(std::path::Path::new("test_data/multi-tree.sgf"), |games| {
            assert_eq!(games.len(), 1);
            let game = &games[0];
            assert_eq!(game.game_type, GameType::Go);
            assert_eq!(
                game.board_size,
                Size {
                    width: 19,
                    height: 19
                }
            );
            assert_eq!(game.trees.len(), 2);
            assert_matches!(game.trees[0].root().unwrap().data(), GameNode::MoveNode(node) => {
                assert_eq!(node.color, Color::Black);
                assert_eq!(node.mv, Move::Move("pd".to_owned()));
            });
            assert_matches!(game.trees[1].root().unwrap().data(), GameNode::MoveNode(node) => {
                assert_eq!(node.color, Color::Black);
                assert_eq!(node.mv, Move::Move("pc".to_owned()));
            });
        });
    }

    #[test]
    fn it_can_copy_a_game_record() {
        with_file(std::path::Path::new("test_data/multi-tree.sgf"), |games| {
            let dest = games.clone();

            assert_eq!(games.len(), dest.len());
            assert_eq!(games[0], dest[0]);
        });
    }
}