// Copyright 2023 Greptime Team
//
// 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 snafu::ensure;
use sql::ast::{ObjectName, ObjectNamePartExt};
use sql::error::{InvalidSqlSnafu, PermissionDeniedSnafu, Result};
use sql::parser::ParserContext;

use crate::QueryContextRef;

/// Parse table name into `(catalog, schema, table)` with query context and validates
/// if catalog matches current catalog in query context.
pub fn table_name_to_full_name(
    name: &str,
    query_ctx: &QueryContextRef,
) -> Result<(String, String, String)> {
    let obj_name = ParserContext::parse_table_name(name, query_ctx.sql_dialect())?;

    let (catalog, schema, table) = table_idents_to_full_name(&obj_name, query_ctx)?;
    // todo(hl): also check if schema matches when rbac is ready. https://github.com/GreptimeTeam/greptimedb/pull/3988/files#r1608687652
    ensure!(
        catalog == query_ctx.current_catalog(),
        PermissionDeniedSnafu {
            target: catalog,
            current: query_ctx.current_catalog(),
        }
    );
    Ok((catalog, schema, table))
}

/// Converts maybe fully-qualified table name (`<catalog>.<schema>.<table>`) to tuple.
pub fn table_idents_to_full_name(
    obj_name: &ObjectName,
    query_ctx: &QueryContextRef,
) -> Result<(String, String, String)> {
    match &obj_name.0[..] {
        [table] => Ok((
            query_ctx.current_catalog().to_string(),
            query_ctx.current_schema().clone(),
            table.to_string_unquoted(),
        )),
        [schema, table] => Ok((
            query_ctx.current_catalog().to_string(),
            schema.to_string_unquoted(),
            table.to_string_unquoted(),
        )),
        [catalog, schema, table] => Ok((
            catalog.to_string_unquoted(),
            schema.to_string_unquoted(),
            table.to_string_unquoted(),
        )),
        _ => InvalidSqlSnafu {
            msg: format!(
                "expect table name to be <catalog>.<schema>.<table>, <schema>.<table> or <table>, actual: {obj_name}",
            ),
        }.fail(),
    }
}
