# for macOS (replace 7 with version of gcc installed on your machine)
# NOTE: your gcc / g++ from Homebrew is probably in /usr/local/bin
#export CXX=/usr/local/bin/g++-8 CC=/usr/local/bin/gcc-8
# Sys.setenv("CXX" = "/usr/local/bin/g++-8")
# Sys.setenv("CC" = "/usr/local/bin/gcc-8")

# R returns FALSE (not a non-zero exit code) if a file copy operation
# breaks. Let's fix that
.handle_result <- function(res){
    if (!res){
        stop("Copying files failed!")
    }
}

# Make a new temporary folder to work in
unlink(x = "lightgbm_r", recursive = TRUE)
dir.create("lightgbm_r")

# copy in the relevant files
result <- file.copy(
    from = "R-package/./"
    , to = "lightgbm_r/"
    , recursive = TRUE
    , overwrite = TRUE
)
.handle_result(result)

result <- file.copy(
    from = "include/"
    , to = file.path("lightgbm_r", "src/")
    , recursive = TRUE
    , overwrite = TRUE
)
.handle_result(result)

result <- file.copy(
    from = "src/"
    , to = file.path("lightgbm_r", "src/")
    , recursive = TRUE
    , overwrite = TRUE
)
.handle_result(result)

result <- file.copy(
    from = "CMakeLists.txt"
    , to = file.path("lightgbm_r", "inst", "bin/")
    , recursive = TRUE
    , overwrite = TRUE
)
.handle_result(result)

# rebuild documentation
devtools::document(
    pkg = "lightgbm_r/"
)

# Build the package
# NOTE: --keep-empty-dirs is necessary to keep the deep paths expected
#       by CMake while also meeting the CRAN req to create object files
#       on demand
devtools::build(
    pkg = "lightgbm_r"
    , args = c("--keep-empty-dirs")
)

# Install the package
version <- gsub(
    "Version: "
    , ""
    , grep(
        "Version: "
        , readLines(con = file.path("lightgbm_r", "DESCRIPTION"))
        , value = TRUE
    )
)
tarball <- file.path(getwd(), sprintf("lightgbm_%s.tar.gz", version))

system(sprintf("R CMD INSTALL %s --no-multi-arch", tarball))

# Run R CMD CHECK
#R CMD CHECK lightgbm_2.1.2.tar.gz --as-cran | tee check.log | cat