databend-common-ast 0.0.0

// Copyright 2021 Datafuse 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 std::collections::BTreeMap;

use nom::branch::alt;
use nom::combinator::map;

use crate::ast::FileFormatOptions;
use crate::ast::FileFormatValue;
use crate::ast::FileLocation;
use crate::ast::SelectStageOption;
use crate::ast::UriLocation;
use crate::parser::common::*;
use crate::parser::expr::*;
use crate::parser::input::Input;
use crate::parser::token::*;
use crate::parser::ErrorKind;
use crate::rule;

pub fn parameter_to_string(i: Input) -> IResult<String> {
    let ident_to_string = |i| map_res(ident, |ident| Ok(ident.name))(i);
    let u64_to_string = |i| map(literal_u64, |v| v.to_string())(i);
    let boolean_to_string = |i| map(literal_bool, |v| v.to_string())(i);

    rule!(
        #literal_string
        | #ident_to_string
        | #u64_to_string
        | #boolean_to_string
    )(i)
}

pub fn connection_opt(sep: &'static str) -> impl FnMut(Input) -> IResult<(String, String)> {
    move |i| {
        let string_options = map(
            rule! {
                #ident ~ #match_text(sep) ~ #literal_string
            },
            |(k, _, v)| (k.to_string().to_lowercase(), v),
        );
        let bool_options = map(
            rule! {
                ENABLE_VIRTUAL_HOST_STYLE ~ #match_text(sep) ~ #literal_bool
            },
            |(k, _, v)| (k.text().to_string().to_lowercase(), v.to_string()),
        );

        rule!(
            #string_options
            | #bool_options
        )(i)
    }
}

pub fn connection_options(i: Input) -> IResult<BTreeMap<String, String>> {
    let connection_opt = connection_opt("=");
    map(
        rule! { "(" ~ ( #connection_opt ~ ","? )* ~ ^")" },
        |(_, opts, _)| {
            BTreeMap::from_iter(opts.iter().map(|((k, v), _)| (k.to_lowercase(), v.clone())))
        },
    )(i)
}

pub fn format_options(i: Input) -> IResult<FileFormatOptions> {
    let option_type = map(
        rule! {
            TYPE ~ "=" ~ ( TSV | CSV | NDJSON | PARQUET | JSON | ORC)
        },
        |(_, _, v)| {
            (
                "type".to_string(),
                FileFormatValue::Keyword(v.text().to_string()),
            )
        },
    );

    let option_compression = map(
        rule! {
            COMPRESSION ~ "=" ~ ( AUTO | NONE | GZIP | BZ2 | BROTLI | ZSTD | DEFLATE | RAWDEFLATE | XZ )
        },
        |(_, _, v)| {
            (
                "COMPRESSION".to_string(),
                FileFormatValue::Keyword(v.text().to_string()),
            )
        },
    );

    let ident_options = map(
        rule! { (BINARY_FORMAT | MISSING_FIELD_AS | EMPTY_FIELD_AS | NULL_FIELD_AS)  ~ "=" ~ (NULL | STRING | Ident)},
        |(k, _, v)| {
            (
                k.text().to_string(),
                FileFormatValue::Keyword(v.text().to_string()),
            )
        },
    );

    let string_options = map(
        rule! {
            (TYPE
                | FORMAT_NAME
                | COMPRESSION
                | RECORD_DELIMITER
                | FIELD_DELIMITER
                | QUOTE
                | NAN_DISPLAY
                | NULL_DISPLAY
                | ESCAPE
                | NULL_FIELD_AS
                | MISSING_FIELD_AS
                | ROW_TAG) ~ ^"=" ~ ^#literal_string
        },
        |(k, _, v)| (k.text().to_string(), FileFormatValue::String(v)),
    );

    let int_options = map(
        rule! {
            SKIP_HEADER ~ ^"=" ~ ^#literal_u64
        },
        |(k, _, v)| (k.text().to_string(), FileFormatValue::U64(v)),
    );

    let bool_options = map(
        rule! {
            (ERROR_ON_COLUMN_COUNT_MISMATCH | OUTPUT_HEADER) ~ ^"=" ~ ^#literal_bool
        },
        |(k, _, v)| (k.text().to_string(), FileFormatValue::Bool(v)),
    );

    let none_options = map(
        rule! {
            (RECORD_DELIMITER
                | FIELD_DELIMITER
                | QUOTE
                | SKIP_HEADER
                | NON_DISPLAY
                | ESCAPE ) ~ ^"=" ~ ^NONE
        },
        |(k, _, v)| {
            (
                k.text().to_string(),
                FileFormatValue::Keyword(v.text().to_string()),
            )
        },
    );

    let null_if = map(
        rule! { NULL_IF ~ ^"=" ~ ^"(" ~ ^#comma_separated_list0(literal_string) ~ ^")" },
        |(_, _, _, values, _)| ("null_if".to_string(), FileFormatValue::StringList(values)),
    );

    map(
        rule! { ((
        #option_type
        | #option_compression
        | #ident_options
        | #string_options
        | #int_options
        | #bool_options
        | #none_options
        | #null_if
        ) ~ ","?)* },
        |opts| FileFormatOptions {
            options: opts
                .iter()
                .map(|((k, v), _)| (k.to_lowercase(), v.clone()))
                .collect(),
        },
    )(i)
}

pub fn file_format_clause(i: Input) -> IResult<FileFormatOptions> {
    map(
        rule! { FILE_FORMAT ~ ^"=" ~ ^"(" ~ ^#format_options ~ ^")" },
        |(_, _, _, opts, _)| opts,
    )(i)
}

// parse: (k = v ...)* into a map
pub fn options(i: Input) -> IResult<BTreeMap<String, String>> {
    map(
        rule! {
            "(" ~ ( #ident ~ ^"=" ~ ^#parameter_to_string ~ ","? )* ~ ^")"
        },
        |(_, opts, _)| {
            BTreeMap::from_iter(
                opts.iter()
                    .map(|(k, _, v, _)| (k.name.to_lowercase(), v.clone())),
            )
        },
    )(i)
}

pub fn file_location(i: Input) -> IResult<FileLocation> {
    alt((
        string_location,
        map_res(at_string, |location| Ok(FileLocation::Stage(location))),
    ))(i)
}

pub fn stage_location(i: Input) -> IResult<String> {
    map_res(file_location, |location| match location {
        FileLocation::Stage(s) => Ok(s),
        FileLocation::Uri(_) => Err(nom::Err::Failure(ErrorKind::Other(
            "expect stage location, got uri location",
        ))),
    })(i)
}

pub fn uri_location(i: Input) -> IResult<UriLocation> {
    map_res(string_location, |location| match location {
        FileLocation::Stage(_) => Err(nom::Err::Failure(ErrorKind::Other(
            "uri location should not start with '@'",
        ))),
        FileLocation::Uri(u) => Ok(u),
    })(i)
}

pub fn string_location(i: Input) -> IResult<FileLocation> {
    map_res(
        rule! {
            #literal_string
            ~ (CONNECTION ~ ^"=" ~ ^#connection_options ~ ","?)?
            ~ (LOCATION_PREFIX ~ ^"=" ~ ^#literal_string ~ ","?)?
        },
        |(location, connection_opts, location_prefix)| {
            if let Some(stripped) = location.strip_prefix('@') {
                if location_prefix.is_none() && connection_opts.is_none() {
                    Ok(FileLocation::Stage(stripped.to_string()))
                } else {
                    Err(nom::Err::Failure(ErrorKind::Other(
                        "uri location should not start with '@'",
                    )))
                }
            } else {
                let part_prefix = if let Some((_, _, p, _)) = location_prefix {
                    p
                } else {
                    "".to_string()
                };
                // fs location is not a valid url, let's check it in advance.

                let conns = connection_opts.map(|v| v.2).unwrap_or_default();

                let uri = UriLocation::from_uri(location, part_prefix, conns)
                    .map_err(|_| nom::Err::Failure(ErrorKind::Other("invalid uri")))?;
                Ok(FileLocation::Uri(uri))
            }
        },
    )(i)
}

pub fn select_stage_option(i: Input) -> IResult<SelectStageOption> {
    alt((
        map(
            rule! { FILES ~ ^"=>" ~ ^"(" ~ ^#comma_separated_list0(literal_string) ~ ^")" },
            |(_, _, _, files, _)| SelectStageOption::Files(files),
        ),
        map(
            rule! { PATTERN ~ ^"=>" ~ ^#literal_string },
            |(_, _, pattern)| SelectStageOption::Pattern(pattern),
        ),
        map(
            rule! { FILE_FORMAT ~ ^"=>" ~ ^#literal_string },
            |(_, _, file_format)| SelectStageOption::FileFormat(file_format),
        ),
        map(
            rule! { CONNECTION ~ ^"=>" ~ ^#connection_options },
            |(_, _, file_format)| SelectStageOption::Connection(file_format),
        ),
    ))(i)
}