use crate::dart_notification::{send_dart_notification, GridNotification};
use crate::manager::GridUser;
use crate::services::block_revision_editor::GridBlockRevisionEditor;
use crate::services::persistence::block_index::BlockIndexCache;
use crate::services::row::{block_from_row_orders, GridBlockSnapshot};
use dashmap::DashMap;
use flowy_error::FlowyResult;
use flowy_grid_data_model::entities::{
    CellChangeset, GridRowsChangeset, IndexRowOrder, Row, RowOrder, UpdatedRowOrder,
};
use flowy_grid_data_model::revision::{
    CellRevision, GridBlockRevision, GridBlockRevisionChangeset, RowMetaChangeset, RowRevision,
};
use flowy_revision::disk::SQLiteGridBlockMetaRevisionPersistence;
use flowy_revision::{RevisionManager, RevisionPersistence};
use std::borrow::Cow;
use std::collections::HashMap;
use std::sync::Arc;

type BlockId = String;
pub(crate) struct GridBlockManager {
    grid_id: String,
    user: Arc<dyn GridUser>,
    persistence: Arc<BlockIndexCache>,
    block_editor_map: DashMap<BlockId, Arc<GridBlockRevisionEditor>>,
}

impl GridBlockManager {
    pub(crate) async fn new(
        grid_id: &str,
        user: &Arc<dyn GridUser>,
        blocks: Vec<GridBlockRevision>,
        persistence: Arc<BlockIndexCache>,
    ) -> FlowyResult<Self> {
        let editor_map = make_block_meta_editor_map(user, blocks).await?;
        let user = user.clone();
        let grid_id = grid_id.to_owned();
        let manager = Self {
            grid_id,
            user,
            block_editor_map: editor_map,
            persistence,
        };
        Ok(manager)
    }

    // #[tracing::instrument(level = "trace", skip(self))]
    pub(crate) async fn get_editor(&self, block_id: &str) -> FlowyResult<Arc<GridBlockRevisionEditor>> {
        debug_assert!(!block_id.is_empty());
        match self.block_editor_map.get(block_id) {
            None => {
                tracing::error!("This is a fatal error, block with id:{} is not exist", block_id);
                let editor = Arc::new(make_block_meta_editor(&self.user, block_id).await?);
                self.block_editor_map.insert(block_id.to_owned(), editor.clone());
                Ok(editor)
            }
            Some(editor) => Ok(editor.clone()),
        }
    }

    async fn get_editor_from_row_id(&self, row_id: &str) -> FlowyResult<Arc<GridBlockRevisionEditor>> {
        let block_id = self.persistence.get_block_id(row_id)?;
        Ok(self.get_editor(&block_id).await?)
    }

    pub(crate) async fn create_row(
        &self,
        block_id: &str,
        row_rev: RowRevision,
        start_row_id: Option<String>,
    ) -> FlowyResult<i32> {
        let _ = self.persistence.insert(&row_rev.block_id, &row_rev.id)?;
        let editor = self.get_editor(&row_rev.block_id).await?;

        let mut index_row_order = IndexRowOrder::from(&row_rev);
        let (row_count, row_index) = editor.create_row(row_rev, start_row_id).await?;
        index_row_order.index = row_index;

        let _ = self
            .notify_did_update_block(block_id, GridRowsChangeset::insert(block_id, vec![index_row_order]))
            .await?;
        Ok(row_count)
    }

    pub(crate) async fn insert_row(
        &self,
        rows_by_block_id: HashMap<String, Vec<RowRevision>>,
    ) -> FlowyResult<Vec<GridBlockRevisionChangeset>> {
        let mut changesets = vec![];
        for (block_id, row_revs) in rows_by_block_id {
            let mut inserted_row_orders = vec![];
            let editor = self.get_editor(&block_id).await?;
            let mut row_count = 0;
            for row in row_revs {
                let _ = self.persistence.insert(&row.block_id, &row.id)?;
                let mut row_order = IndexRowOrder::from(&row);
                let (count, index) = editor.create_row(row, None).await?;
                row_count = count;
                row_order.index = index;
                inserted_row_orders.push(row_order);
            }
            changesets.push(GridBlockRevisionChangeset::from_row_count(&block_id, row_count));

            let _ = self
                .notify_did_update_block(&block_id, GridRowsChangeset::insert(&block_id, inserted_row_orders))
                .await?;
        }

        Ok(changesets)
    }

    pub async fn update_row<F>(&self, changeset: RowMetaChangeset, row_builder: F) -> FlowyResult<()>
    where
        F: FnOnce(Arc<RowRevision>) -> Option<Row>,
    {
        let editor = self.get_editor_from_row_id(&changeset.row_id).await?;
        let _ = editor.update_row(changeset.clone()).await?;
        match editor.get_row_rev(&changeset.row_id).await? {
            None => tracing::error!("Internal error: can't find the row with id: {}", changeset.row_id),
            Some(row_rev) => {
                if let Some(row) = row_builder(row_rev.clone()) {
                    let row_order = UpdatedRowOrder::new(&row_rev, row);
                    let block_order_changeset = GridRowsChangeset::update(&editor.block_id, vec![row_order]);
                    let _ = self
                        .notify_did_update_block(&editor.block_id, block_order_changeset)
                        .await?;
                }
            }
        }
        Ok(())
    }

    pub async fn delete_row(&self, row_id: &str) -> FlowyResult<()> {
        let row_id = row_id.to_owned();
        let block_id = self.persistence.get_block_id(&row_id)?;
        let editor = self.get_editor(&block_id).await?;
        match editor.get_row_order(&row_id).await? {
            None => {}
            Some(row_order) => {
                let _ = editor.delete_rows(vec![Cow::Borrowed(&row_id)]).await?;
                let _ = self
                    .notify_did_update_block(&block_id, GridRowsChangeset::delete(&block_id, vec![row_order]))
                    .await?;
            }
        }

        Ok(())
    }

    pub(crate) async fn delete_rows(&self, row_orders: Vec<RowOrder>) -> FlowyResult<Vec<GridBlockRevisionChangeset>> {
        let mut changesets = vec![];
        for block_order in block_from_row_orders(row_orders) {
            let editor = self.get_editor(&block_order.id).await?;
            let row_ids = block_order
                .row_orders
                .into_iter()
                .map(|row_order| Cow::Owned(row_order.row_id))
                .collect::<Vec<Cow<String>>>();
            let row_count = editor.delete_rows(row_ids).await?;
            let changeset = GridBlockRevisionChangeset::from_row_count(&block_order.id, row_count);
            changesets.push(changeset);
        }

        Ok(changesets)
    }

    pub(crate) async fn move_row(&self, row_id: &str, from: usize, to: usize) -> FlowyResult<()> {
        let editor = self.get_editor_from_row_id(row_id).await?;
        let _ = editor.move_row(row_id, from, to).await?;

        match editor.get_row_revs(Some(vec![Cow::Borrowed(row_id)])).await?.pop() {
            None => {}
            Some(row_rev) => {
                let row_order = RowOrder::from(&row_rev);
                let insert_row = IndexRowOrder {
                    row_order: row_order.clone(),
                    index: Some(to as i32),
                };
                let notified_changeset = GridRowsChangeset {
                    block_id: editor.block_id.clone(),
                    inserted_rows: vec![insert_row],
                    deleted_rows: vec![row_order],
                    updated_rows: vec![],
                };

                let _ = self
                    .notify_did_update_block(&editor.block_id, notified_changeset)
                    .await?;
            }
        }

        Ok(())
    }

    pub async fn update_cell<F>(&self, changeset: CellChangeset, row_builder: F) -> FlowyResult<()>
    where
        F: FnOnce(Arc<RowRevision>) -> Option<Row>,
    {
        let row_changeset: RowMetaChangeset = changeset.clone().into();
        let _ = self.update_row(row_changeset, row_builder).await?;
        self.notify_did_update_cell(changeset).await?;
        Ok(())
    }

    pub async fn get_row_rev(&self, row_id: &str) -> FlowyResult<Option<Arc<RowRevision>>> {
        let editor = self.get_editor_from_row_id(row_id).await?;
        let row_ids = vec![Cow::Borrowed(row_id)];
        let mut row_revs = editor.get_row_revs(Some(row_ids)).await?;
        if row_revs.is_empty() {
            Ok(None)
        } else {
            Ok(row_revs.pop())
        }
    }

    pub async fn get_row_orders(&self, block_id: &str) -> FlowyResult<Vec<RowOrder>> {
        let editor = self.get_editor(block_id).await?;
        editor.get_row_orders::<&str>(None).await
    }

    pub(crate) async fn make_block_snapshots(&self, block_ids: Vec<String>) -> FlowyResult<Vec<GridBlockSnapshot>> {
        let mut snapshots = vec![];
        for block_id in block_ids {
            let editor = self.get_editor(&block_id).await?;
            let row_revs = editor.get_row_revs::<&str>(None).await?;
            snapshots.push(GridBlockSnapshot { block_id, row_revs });
        }
        Ok(snapshots)
    }

    // Optimization: Using the shared memory(Arc, Cow,etc.) to reduce memory usage.
    #[allow(dead_code)]
    pub async fn get_cell_revs(
        &self,
        block_ids: Vec<String>,
        field_id: &str,
        row_ids: Option<Vec<Cow<'_, String>>>,
    ) -> FlowyResult<Vec<CellRevision>> {
        let mut block_cell_revs = vec![];
        for block_id in block_ids {
            let editor = self.get_editor(&block_id).await?;
            let cell_revs = editor.get_cell_revs(field_id, row_ids.clone()).await?;
            block_cell_revs.extend(cell_revs);
        }
        Ok(block_cell_revs)
    }

    async fn notify_did_update_block(&self, block_id: &str, changeset: GridRowsChangeset) -> FlowyResult<()> {
        send_dart_notification(block_id, GridNotification::DidUpdateGridRow)
            .payload(changeset)
            .send();
        Ok(())
    }

    async fn notify_did_update_cell(&self, changeset: CellChangeset) -> FlowyResult<()> {
        let id = format!("{}:{}", changeset.row_id, changeset.field_id);
        send_dart_notification(&id, GridNotification::DidUpdateCell).send();
        Ok(())
    }
}

async fn make_block_meta_editor_map(
    user: &Arc<dyn GridUser>,
    blocks: Vec<GridBlockRevision>,
) -> FlowyResult<DashMap<String, Arc<GridBlockRevisionEditor>>> {
    let editor_map = DashMap::new();
    for block in blocks {
        let editor = make_block_meta_editor(user, &block.block_id).await?;
        editor_map.insert(block.block_id, Arc::new(editor));
    }

    Ok(editor_map)
}

async fn make_block_meta_editor(user: &Arc<dyn GridUser>, block_id: &str) -> FlowyResult<GridBlockRevisionEditor> {
    tracing::trace!("Open block:{} meta editor", block_id);
    let token = user.token()?;
    let user_id = user.user_id()?;
    let pool = user.db_pool()?;

    let disk_cache = Arc::new(SQLiteGridBlockMetaRevisionPersistence::new(&user_id, pool));
    let rev_persistence = Arc::new(RevisionPersistence::new(&user_id, block_id, disk_cache));
    let rev_manager = RevisionManager::new(&user_id, block_id, rev_persistence);
    GridBlockRevisionEditor::new(&user_id, &token, block_id, rev_manager).await
}