extern crate gcc;

use std::fs;

fn link(name: &str, bundled: bool) {
    use std::env::var;
    let target = var("TARGET").unwrap();
    let target: Vec<_> = target.split('-').collect();
    if target.get(2) == Some(&"windows") {
        println!("cargo:rustc-link-lib=dylib={}", name);
        if bundled && target.get(3) == Some(&"gnu") {
            let dir = var("CARGO_MANIFEST_DIR").unwrap();
            println!("cargo:rustc-link-search=native={}/{}", dir, target[0]);
        }
    }
}

fn fail_on_empty_directory(name: &str) {
    if fs::read_dir(name).unwrap().count() == 0 {
        println!("The `{}` directory is empty, did you forget to pull the submodules?", name);
        println!("Try `git submodule update --init --recursive`");
        panic!();
    }
}

fn build_rocksdb() {
    println!("cargo:rerun-if-changed=build.rs");
    println!("cargo:rerun-if-changed=rocksdb/");

    let mut config = gcc::Config::new();
    config.include("rocksdb/include/");
    config.include("rocksdb/");
    config.include("rocksdb/third-party/gtest-1.7.0/fused-src/");
    config.include("snappy/");
    config.include(".");

    config.define("NDEBUG", Some("1"));
    config.define("SNAPPY", Some("1"));

    let mut lib_sources = include_str!("rocksdb_lib_sources.txt")
        .split(" ")
        .collect::<Vec<&'static str>>();

    // We have a pregenerated a version of build_version.cc in the local directory
    lib_sources = lib_sources.iter()
        .cloned()
        .filter(|file| *file != "util/build_version.cc")
        .collect::<Vec<&'static str>>();

    if cfg!(target_os = "macos") {
        config.define("OS_MACOSX", Some("1"));
        config.define("ROCKSDB_PLATFORM_POSIX", Some("1"));
        config.define("ROCKSDB_LIB_IO_POSIX", Some("1"));

    }
    if cfg!(target_os = "linux") {
        config.define("OS_LINUX", Some("1"));
        config.define("ROCKSDB_PLATFORM_POSIX", Some("1"));
        config.define("ROCKSDB_LIB_IO_POSIX", Some("1"));
        // COMMON_FLAGS="$COMMON_FLAGS -fno-builtin-memcmp"
    }
    if cfg!(target_os = "freebsd") {
        config.define("OS_FREEBSD", Some("1"));
        config.define("ROCKSDB_PLATFORM_POSIX", Some("1"));
        config.define("ROCKSDB_LIB_IO_POSIX", Some("1"));
    }

    if cfg!(windows) {
        link("rpcrt4", false);
        config.define("OS_WIN", Some("1"));
        config.define("NOMINMAX", Some("1"));

        // Remove POSIX-specific sources
        lib_sources = lib_sources.iter()
            .cloned()
            .filter(|file| {
                match *file {
                    "port/port_posix.cc" |
                    "util/env_posix.cc" |
                    "env/env_posix.cc" |
                    "env/io_posix.cc" => false,
                    _ => true,
                }
            })
            .collect::<Vec<&'static str>>();

        // Add Windows-specific sources
        lib_sources.push("port/win/port_win.cc");
        lib_sources.push("port/win/env_win.cc");
        lib_sources.push("port/win/env_default.cc");
        lib_sources.push("port/win/win_logger.cc");
        lib_sources.push("port/win/win_thread.cc");
        lib_sources.push("port/win/io_win.cc");
        lib_sources.push("port/win/xpress_win.cc");
    }

    if cfg!(target_env = "msvc") {
        config.flag("-EHsc");
    } else {
        config.flag("-std=c++11");
    }

    for file in lib_sources {
        let file = "rocksdb/".to_string() + file;
        config.file(&file);
    }

    config.file("build_version.cc");

    config.cpp(true);
    config.compile("librocksdb_emerald.a");
}

fn build_snappy() {
    let mut config = gcc::Config::new();
    config.include("snappy/");
    config.include(".");

    config.define("NDEBUG", Some("1"));

    if cfg!(target_env = "msvc") {
        config.flag("-EHsc");
    } else {
        config.flag("-std=c++11");
    }

    config.file("snappy/snappy.cc");
    config.file("snappy/snappy-sinksource.cc");
    config.file("snappy/snappy-c.cc");
    config.cpp(true);
    config.compile("libsnappy.a");
}

fn main() {
    fail_on_empty_directory("rocksdb");
    fail_on_empty_directory("snappy");
    build_rocksdb();
    build_snappy();
}