// Copyright (c) 2013-2014 Sandstorm Development Group, Inc. and contributors
// Licensed under the MIT License:
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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// THE SOFTWARE.

//! # Cap'n Proto Schema Compiler Plugin Library
//!
//! This library allows you to do [Cap'n Proto code generation]
//! (https://capnproto.org/otherlang.html#how-to-write-compiler-plugins) within
//! a Cargo build. You still need the `capnp` binary (implemented in C++).
//! (If you use a package manager, try looking for a package called
//! `capnproto`.)
//!
//! In your Cargo.toml:
//!
//! ```ignore
//! [package]
//! build = "build.rs"
//!
//! [build-dependencies]
//! capnpc = "0.8"
//! ```
//!
//! In your build.rs:
//!
//! ```ignore
//! extern crate capnpc;
//!
//! fn main() {
//!     capnpc::CompilerCommand::new()
//!         .src_prefix("schema")
//!         .file("schema/foo.capnp")
//!         .file("schema/bar.capnp")
//!         .run().expect("schema compiler command");
//! }
//! ```
//!
//! This will be equivalent to executing the shell command
//!
//! ```ignore
//!   capnp compile -orust:$OUT_DIR --src-prefix=schema schema/foo.capnp schema/bar.capnp
//! ```
//!

extern crate capnp;

/// Code generated from [schema.capnp]
/// (https://github.com/sandstorm-io/capnproto/blob/master/c%2B%2B/src/capnp/schema.capnp).
pub mod schema_capnp;

pub mod codegen;
pub mod codegen_types;
pub mod schema;

use std::path::{Path, PathBuf};

fn run_command(mut command: ::std::process::Command) -> ::capnp::Result<()> {
    let mut p = try!(command.spawn());
    try!(::codegen::main(p.stdout.take().unwrap(),
                         ::std::path::Path::new(&::std::env::var("OUT_DIR").unwrap())));
    let exit_status = try!(p.wait());
    if !exit_status.success() {
        Err(::capnp::Error::failed(format!("Non-success exit status: {}", exit_status)))
    } else {
        Ok(())
    }
}

/// A builder object for schema compiler commands.
pub struct CompilerCommand {
    files: Vec<PathBuf>,
    src_prefixes: Vec<PathBuf>,
    import_paths: Vec<PathBuf>,
    no_standard_import: bool,
}

impl CompilerCommand {
    /// Creates a new, empty command.
    pub fn new() -> CompilerCommand {
        CompilerCommand {
            files: Vec::new(),
            src_prefixes: Vec::new(),
            import_paths: Vec::new(),
            no_standard_import: false,
        }
    }

    /// Adds a file to be compiled.
    pub fn file<'a, P>(&'a mut self, path: P) -> &'a mut CompilerCommand
        where P: AsRef<Path>,
    {
        self.files.push(path.as_ref().to_path_buf());
        self
    }

    /// Adds a --src-prefix flag. For all files specified for compilation that start
    /// with `prefix`, removes the prefix when computing output filenames.
    pub fn src_prefix<'a, P>(&'a mut self, prefix: P) -> &'a mut CompilerCommand
        where P: AsRef<Path>,
    {
        self.src_prefixes.push(prefix.as_ref().to_path_buf());
        self
    }

    /// Adds an --import_path flag. Adds `dir` to the list of directories searched
    /// for absolute imports.
    pub fn import_path<'a, P>(&'a mut self, dir: P) -> &'a mut CompilerCommand
        where P: AsRef<Path>,
    {
        self.import_paths.push(dir.as_ref().to_path_buf());
        self
    }

    /// Adds the --no-standard-import flag, indicating that the default import paths of
    /// /usr/include and /usr/local/include should not bet included.
    pub fn no_standard_import<'a>(&'a mut self) -> &'a mut CompilerCommand {
        self.no_standard_import = true;
        self
    }

    /// Runs the command.
    pub fn run(&mut self) -> ::capnp::Result<()> {
        let mut command = ::std::process::Command::new("capnp");
        command.arg("compile").arg("-o").arg("-");

        if self.no_standard_import {
            command.arg("--no-standard-import");
        }

        for import_path in &self.import_paths {
            command.arg(&format!("--import-path={}", import_path.display()));
        }

        for src_prefix in &self.src_prefixes {
            command.arg(&format!("--src-prefix={}", src_prefix.display()));
        }

        for file in &self.files {
            command.arg(&format!("{}", file.display()));
        }

        command.stdout(::std::process::Stdio::piped());
        command.stderr(::std::process::Stdio::inherit());

        run_command(command).map_err(|error| {
            ::capnp::Error::failed(format!(
                "Error while trying to execute `capnp compile`: {}.  \
                 Please verify that version 0.5.2 or higher of the capnp executable \
                 is installed on your system. See https://capnproto.org/install.html",
                error))})
    }
}