// Licensed to the Apache Software Foundation (ASF) under one
// or more contributor license agreements.  See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership.  The ASF licenses this file
// to you 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.

//! Binary file to print the schema and metadata of a Parquet file.
//!
//! # Install
//!
//! `parquet-schema` can be installed using `cargo`:
//! ```
//! cargo install parquet
//! ```
//! After this `parquet-schema` should be globally available:
//! ```
//! parquet-schema XYZ.parquet
//! ```
//!
//! The binary can also be built from the source code and run as follows:
//! ```
//! cargo run --bin parquet-schema XYZ.parquet
//! ```
//!
//! # Usage
//!
//! ```
//! parquet-schema <file-path> [verbose]
//! ```
//! where `file-path` is the path to a Parquet file and `verbose` is the optional boolean
//! flag that allows to print schema only, when set to `false` (default behaviour when
//! not provided), or print full file metadata, when set to `true`.
//! For example,
//! ```
//! parquet-schema data/alltypes_plain.snappy.parquet
//!
//! parquet-schema data/alltypes_plain.snappy.parquet false
//!
//! parquet-schema data/alltypes_plain.snappy.parquet true
//! ```

extern crate parquet;

use std::env;
use std::fs::File;
use std::path::Path;
use std::process;

use parquet::file::reader::{FileReader, SerializedFileReader};
use parquet::schema::printer::{print_file_metadata, print_parquet_metadata};

fn main() {
  let args: Vec<String> = env::args().collect();
  if args.len() != 2 && args.len() != 3 {
    println!("Usage: parquet-schema <file-path> [verbose]");
    process::exit(1);
  }
  let path = Path::new(&args[1]);
  let mut verbose = false;
  if args.len() == 3 {
    match args[2].parse() {
      Ok(b) => verbose = b,
      Err(e) => panic!(
        "Error when reading value for [verbose] \
         (expected either 'true' or 'false'): {}",
        e
      )
    }
  }
  let file = match File::open(&path) {
    Err(e) => panic!("Error when opening file {}: {}", path.display(), e),
    Ok(f) => f
  };
  match SerializedFileReader::new(file) {
    Err(e) => panic!("Error when parsing Parquet file: {}", e),
    Ok(parquet_reader) => {
      let metadata = parquet_reader.metadata();
      println!("Metadata for file: {}", &args[1]);
      println!("");
      if verbose {
        print_parquet_metadata(&mut std::io::stdout(), &metadata);
      } else {
        print_file_metadata(&mut std::io::stdout(), &metadata.file_metadata());
      }
    }
  }
}
