#!/bin/bash
# vim: ft=sh

_meson_dir=`pwd`
_meson_lang=c

while getopts ":hl:" o; do
    case $o in
        l)
            _meson_lang=$OPTARG
            ;;
        h | *)
            echo "usage: $0 [flags]"
            echo ""
            echo "-h :: print help"
            echo "-l LANG (default: c) :: language to use"
            echo ""
            exit 0
            ;;
    esac
done
shift $((OPTIND - 1))

log() {
    echo "[*] ${@}" >&2
}

# allow setting target dir
if [[ -n $1 ]]; then
    _meson_dir="$1"
    [[ ! -d $_meson_dir ]] && mkdir -p $_meson_dir
    log "creating in $_meson_dir"
fi

_meson_bin=`basename $_meson_dir`
_meson_ignore_extra=
declare -a _meson_default_options
declare -a _meson_default_files

case $_meson_lang in

    ### C ###
    c)
        _meson_default_options=( \
            'c_std=c11' \
            'warning_level=2' \
            'werror=true' \
        )
        _meson_default_files=('src/main.c')
        _meson_ignore_extra='**/*.o'
        _meson_output="
x = executable(
    '$_meson_bin',
    sources: src
)"

        log "writing main.c"
        mkdir $_meson_dir/src
        cat > $_meson_dir/src/main.c <<EOF
#define _POSIX_C_SOURCE 200809L

#ifndef VERSION
#define VERSION "undefined"
#endif

#include <stdlib.h>
#include <stdio.h>

int main(int argc, char **argv) {
    printf("%s version %s\n\n", *argv, VERSION);

    printf("args (len: %d)", argc-1);
    for (int i=1; i < argc; ++i) {
        printf(" '%s'", argv[i]);
    }
    printf("\n");
    return 0;
}
EOF
        ;;

    ### JAVA ###
    java)
        _meson_default_options=
        _meson_default_files=('pkg/Main.class')
        _meson_ignore_extra='**/*.jar'
        _meson_output="
x = jar(
    '$_meson_bin',
    main_class: 'pkg.Main',
    sources: src
)
"

        log "writing Main.java"
        mkdir $_meson_dir/pkg
        cat > $_meson_dir/pkg/Main.java <<EOF
package pkg

class Main {
    public static void main(String[] args) {
        System.out.println("hello world o/");
    }
}
EOF
        ;;


    *)
        log "$_meson_lang not supported yet :("
        exit 1
        ;;
esac

meson_array_expand() {
    for o in "${@}"; do 
        printf "\t'%s',\n" $o
    done
}

log "writing meson.build"
cat > $_meson_dir/meson.build <<EOF
project(
    '$_meson_bin',
    '$_meson_lang',
    version: '0.1.0',
    license: 'MIT',
    default_options: [
`meson_array_expand ${_meson_default_options[@]}`
    ],
)

version = '"@0@ (" __DATE__ ")"'.format(meson.project_version())

# embed version sourced from git ref
git = find_program('git', native: true, required: false)
if git.found()
    git_commit_hash = run_command([git.path(), 'describe', '--always', '--tags'])
    git_branch = run_command([git.path(), 'rev-parse', '--abbrev-ref', 'HEAD'])
    if git_commit_hash.returncode() == 0 and git_branch.returncode() == 0
	version = '"@0@ (" __DATE__ ", branch \'@1@\')"'.format(git_commit_hash.stdout().strip(), git_branch.stdout().strip())
    endif
endif
add_project_arguments('-DVERSION=@0@'.format(version), language: 'c')

src = files(
`meson_array_expand ${_meson_default_files[@]}`
)

$_meson_output

test('smoke', x)
EOF

log "intialializing git"
git init -q $_meson_dir

log "writing .gitignore"
cat > $_meson_dir/.gitignore <<EOF
/build
$_meson_ignore_extra
EOF

log "writing Makefile"
cat > $_meson_dir/Makefile <<EOF
RT ?= podman
IMAGE ?= docker.io/robertgzr/mesonbuild-$_meson_lang

all: clean compile

build/build.ninja:
	meson build

build/$_meson_bin$([[ $_meson_lang -eq java ]] && echo '.jar'): compile
build: build/build.ninja
	ninja -C build

test: build/$_meson_bin$([[ $_meson_lang -eq java ]] && echo '.jar')
	ninja -C build test

cbuild:
        \$(RT) run --rm -it -v \$(shell pwd):/src -w /src \$(IMAGE) make

ctest:
        \$(RT) run --rm -it -v \$(shell pwd):/src -w /src \$(IMAGE) make test

clean:
	\$(RM) -r build

.PHONY: clean build test cbuild ctest
EOF