// Copyright 2022 RisingWave Labs
//
// 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.

use pretty_xmlish::{Pretty, XmlNode};
use risingwave_common::catalog::{ColumnDesc, INITIAL_TABLE_VERSION_ID};
use risingwave_pb::stream_plan::stream_node::PbNodeBody;

use super::stream::prelude::*;
use super::utils::{Distill, childless_record};
use super::{ExprRewritable, PlanBase, PlanTreeNodeUnary, StreamNode, StreamPlanRef as PlanRef};
use crate::optimizer::plan_node::expr_visitable::ExprVisitable;
use crate::optimizer::property::{MonotonicityMap, WatermarkColumns};
use crate::stream_fragmenter::BuildFragmentGraphState;

#[derive(Debug, Clone, PartialEq, Eq, Hash)]
pub struct StreamDml {
    pub base: PlanBase<Stream>,
    input: PlanRef,
    column_descs: Vec<ColumnDesc>,
}

impl StreamDml {
    // `append_only` indicates whether only `INSERT` is allowed.
    pub fn new(input: PlanRef, append_only: bool, column_descs: Vec<ColumnDesc>) -> Self {
        let base = PlanBase::new_stream(
            input.ctx(),
            input.schema().clone(),
            input.stream_key().map(|v| v.to_vec()),
            input.functional_dependency().clone(),
            input.distribution().clone(),
            input.stream_kind().merge(if append_only {
                // For append-only table. Either there will be a `RowIdGen` following the `Dml` and `Union`,
                // or there will be a `Materialize` with conflict handling enabled. In both cases there
                // will be no key conflict, so we can treat the merged stream as append-only here.
                StreamKind::AppendOnly
            } else {
                // We cannot guarantee that there's no conflict on stream key between upstream
                // source and DML input, so we must treat it as upsert here.
                StreamKind::Upsert
            }),
            false,                   // TODO(rc): decide EOWC property
            WatermarkColumns::new(), // no watermark if dml is allowed
            MonotonicityMap::new(),  // TODO: derive monotonicity
        );

        Self {
            base,
            input,
            column_descs,
        }
    }

    fn column_names(&self) -> Vec<&str> {
        self.column_descs
            .iter()
            .map(|column_desc| column_desc.name.as_str())
            .collect()
    }
}

impl Distill for StreamDml {
    fn distill<'a>(&self) -> XmlNode<'a> {
        let col = self
            .column_names()
            .iter()
            .map(|n| Pretty::from(n.to_string()))
            .collect();
        let col = Pretty::Array(col);
        childless_record("StreamDml", vec![("columns", col)])
    }
}

impl PlanTreeNodeUnary<Stream> for StreamDml {
    fn input(&self) -> PlanRef {
        self.input.clone()
    }

    fn clone_with_input(&self, input: PlanRef) -> Self {
        Self::new(input, self.append_only(), self.column_descs.clone())
    }
}

impl_plan_tree_node_for_unary! { Stream, StreamDml}

impl StreamNode for StreamDml {
    fn to_stream_prost_body(&self, _state: &mut BuildFragmentGraphState) -> PbNodeBody {
        use risingwave_pb::stream_plan::*;

        PbNodeBody::Dml(Box::new(DmlNode {
            table_id: 0.into(),                         // Meta will fill this table id.
            table_version_id: INITIAL_TABLE_VERSION_ID, // Meta will fill this version id.
            column_descs: self.column_descs.iter().map(Into::into).collect(),
            rate_limit: self.base.ctx().overwrite_options().dml_rate_limit,
        }))
    }
}

impl ExprRewritable<Stream> for StreamDml {}

impl ExprVisitable for StreamDml {}
