// Copyright 2023 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 risingwave_common::catalog::CreateType;
use risingwave_common::id::{IndexId, SchemaId, TableId, UserId};
use risingwave_common::types::{Fields, Timestamptz};
use risingwave_frontend_macro::system_catalog;

use crate::catalog::index_catalog::IndexType;
use crate::catalog::system_catalog::SysCatalogReaderImpl;
use crate::error::Result;

#[derive(Fields)]
struct RwIndex {
    #[primary_key]
    id: IndexId,
    name: String,
    primary_table_id: TableId,
    key_columns: Vec<i16>,
    include_columns: Vec<i16>,
    schema_id: SchemaId,
    owner: UserId,
    definition: String,
    acl: Vec<String>,
    initialized_at: Option<Timestamptz>,
    created_at: Option<Timestamptz>,
    initialized_at_cluster_version: Option<String>,
    created_at_cluster_version: Option<String>,
    background_ddl: bool,
}

#[system_catalog(table, "rw_catalog.rw_indexes")]
fn read_rw_indexes(reader: &SysCatalogReaderImpl) -> Result<Vec<RwIndex>> {
    let catalog_reader = reader.catalog_reader.read_guard();
    let schemas = catalog_reader.iter_schemas(&reader.auth_context.database)?;
    let user_reader = reader.user_info_reader.read_guard();
    let current_user = user_reader
        .get_user_by_name(&reader.auth_context.user_name)
        .expect("user not found");

    Ok(schemas
        .flat_map(|schema| {
            schema.iter_index_with_acl(current_user).map(|index| {
                let (index_table, index_columns_len) = match &index.index_type {
                    IndexType::Table(index) => (&index.index_table, index.index_columns_len),
                    IndexType::Vector(index) => (&index.index_table, 1),
                };
                RwIndex {
                    id: index.id,
                    name: index.name.clone(),
                    primary_table_id: index.primary_table.id(),
                    key_columns: index
                        .index_item
                        .iter()
                        .take(index_columns_len as usize)
                        .map(|index| {
                            let ind = if let Some(input_ref) = index.as_input_ref() {
                                input_ref.index() + 1
                            } else {
                                0
                            };
                            ind as i16
                        })
                        .collect(),
                    include_columns: index
                        .index_item
                        .iter()
                        .skip(index_columns_len as usize)
                        .map(|index| {
                            let ind = if let Some(input_ref) = index.as_input_ref() {
                                input_ref.index() + 1
                            } else {
                                0
                            };
                            ind as i16
                        })
                        .collect(),
                    schema_id: schema.id(),
                    owner: index.index_table().owner,
                    definition: index_table.create_sql(),
                    acl: vec![],
                    initialized_at: index.initialized_at_epoch.map(|e| e.as_timestamptz()),
                    created_at: index.created_at_epoch.map(|e| e.as_timestamptz()),
                    initialized_at_cluster_version: index.initialized_at_cluster_version.clone(),
                    created_at_cluster_version: index.created_at_cluster_version.clone(),
                    background_ddl: index.create_type == CreateType::Background,
                }
            })
        })
        .collect())
}
