#!/usr/bin/env bash

cd $(dirname "$(pwd)/$0")
REPOSITORY_FOLDER=$(pwd)


PROJECT_NAME="mach"
DEBUG_CC_OPTIONS="-g3 -Wall -Wextra -Wpedantic"
RELEASE_CC_OPTIONS="-O3 -Wall"

MAIN_OBJECTS_FOLDER="$REPOSITORY_FOLDER/.build/objects"
CONFIG_FILE_INCLUDE_PATHS="build-config/include_paths.txt"

DEFAULT_TEST_INCLUDE_PATHS="
-I .build/depends/libRR/Core/core/exports/
-I .build/depends/libRR/Core/platform/exports/
-I core/exports/
-I core/inc-c/"

DEFAULT_TEST_LINKAGE_PATHS="
$REPOSITORY_FOLDER/.build/librr-core.a
$REPOSITORY_FOLDER/.build/librr-platform.a"


function clone_dependencies {
    echo "================ Cloning Dependencies! ================"
    mkdir -p .build/depends/libRR
    cd .build/depends/libRR/
    if [[ -d "Core" ]]
    then
        rm -rf Core
    fi
    git clone --depth=1 https://git.nerdcult.net/libRR/Core/

    cd "$REPOSITORY_FOLDER"
}

function build_dependencies {
    echo "================ Building Dependencies! ================"
    
    mkdir -p "$REPOSITORY_FOLDER/.build/output"

    cd .build/depends/libRR/Core/
    bash build.bash release
    cp .build/librr-core.a "$REPOSITORY_FOLDER/.build"
    cp .build/librr-platform.a "$REPOSITORY_FOLDER/.build"

    cd "$REPOSITORY_FOLDER"
}

function get_include_path_configuration {
    MODULE_NAME=$1

    INCLUDE_CONFIG_PATH="$REPOSITORY_FOLDER/$MODULE_NAME/$CONFIG_FILE_INCLUDE_PATHS"
    INCLUDE_STATEMENTS="-I $REPOSITORY_FOLDER/$MODULE_NAME/inc-c/"
    if [[ ! -f $INCLUDE_CONFIG_PATH ]]
    then
        return
    fi

    for LINE in $(cat $INCLUDE_CONFIG_PATH)
    do
        INCLUDE_STATEMENTS="$INCLUDE_STATEMENTS -I $REPOSITORY_FOLDER/$LINE"
    done
}

function generate_object_name {
    INPUT_NAME=$1

    NUM_SUBPATHS=$(echo $INPUT_NAME | tr -cd "/" | wc -c)
    SANITIZED_INPUT_NAME=$(echo $INPUT_NAME | tr "/" "_")

    OBJECT_NAME="$NUM_SUBPATHS-$SANITIZED_INPUT_NAME.o"
}

function compile_module_c_sources {
    MODULE_NAME=$1

    get_include_path_configuration $MODULE_NAME

    MODULE_SOURCE_PATH="$REPOSITORY_FOLDER/$MODULE_NAME/src-c"
    MODULE_OBJECTS_FOLDER="$MAIN_OBJECTS_FOLDER/$MODULE_NAME"
    rm -r $MODULE_OBJECTS_FOLDER
    mkdir -p $MODULE_OBJECTS_FOLDER

    # Loop through all files in the 'src-c'-folder and hand them over to GCC

    cd $MODULE_SOURCE_PATH
    MODULE_SOURCES=$(find . -mindepth 1)
    for SOURCE_FOLDER_ITEM in $MODULE_SOURCES
    do
        # Cut away the dot-slash given by 'find' as abbrevation for the working directory
        RELATIVE_SOURCE_PATH=$(echo $SOURCE_FOLDER_ITEM | cut -c "3-")

        # If this folder item is a folder, it must be created as an 
        # output-folder for the object files to be placed in
        
        if [[ -d $RELATIVE_SOURCE_PATH ]]
        then
            mkdir -p "$MODULE_OBJECTS_FOLDER/$RELATIVE_SOURCE_PATH"
            continue
        fi
        
        # Check if this is a C source file by checking the last 2 characters (the ending),
        # and if it isn't, continue with the next file.

        LEN_SOURCE_FILE_NAME=${#RELATIVE_SOURCE_PATH}
        let PENULTIMATE_OFFSET=$LEN_SOURCE_FILE_NAME-1
        LAST_2_CHARACTERS=$(echo $RELATIVE_SOURCE_PATH | cut -c "$PENULTIMATE_OFFSET-")
        if [[ $LAST_2_CHARACTERS != ".c" ]]; then continue; fi
        
        # Status Message
        echo "==> File:          $RELATIVE_SOURCE_PATH"

        # Finally, call GCC to compile the C-file and let it place the file in the
        # objects folder or one of the possible subfolders which now could exist.

        generate_object_name $RELATIVE_SOURCE_PATH
        
        gcc -c $CC_OPTIONS -o \
            "$MODULE_OBJECTS_FOLDER/$OBJECT_NAME" \
            "$MODULE_SOURCE_PATH/$RELATIVE_SOURCE_PATH" \
            $INCLUDE_STATEMENTS
    done

    ar -rvs $REPOSITORY_FOLDER/.build/$PROJECT_NAME-$MODULE_NAME.a $MODULE_OBJECTS_FOLDER/*
    cd $REPOSITORY_FOLDER
}

function get_test_linkage_path_configuration() {
    TEST_PATH=$1

    LINKAGE_PATHS=$DEFAULT_TEST_LINKAGE_PATHS
    if [[ -f "$TEST_PATH/linkage_paths.txt" ]]
    then
        for LINKAGE_ITEM in $(cat "$TEST_PATH/linkage_paths.txt")
        do
            LINKAGE_PATHS="$LINKAGE_PATHS $REPOSITORY_FOLDER/$LINKAGE_ITEM"
        done
    fi
}

function get_test_include_path_configuration() {
    TEST_PATH=$1

    INCLUDE_CONFIG_PATH="$TEST_PATH/include_paths.txt"
    INCLUDE_STATEMENTS="$DEFAULT_TEST_INCLUDE_PATHS -I $TEST_PATH/inc-c/"
    if [[ ! -f $INCLUDE_CONFIG_PATH ]]
    then
        return
    fi

    for LINE in $(cat $INCLUDE_CONFIG_PATH)
    do
        INCLUDE_STATEMENTS="$INCLUDE_STATEMENTS -I $REPOSITORY_FOLDER/$LINE"
    done
}


function compile_single_test() {
    TEST_PATH=$1
    TEST_NAME=$(basename $TEST_PATH)

    echo "Compiling Test: $TEST_NAME"

    # TODO: As a small improvement, the tests could be able to have multiple sub-folders for sources.

    get_test_include_path_configuration $TEST_PATH
    get_test_linkage_path_configuration $TEST_PATH
    gcc $CC_OPTIONS -o $TEST_PATH/$TEST_NAME.elf $TEST_PATH/*.c $LINKAGE_PATHS $INCLUDE_STATEMENTS
}

function compile_all_tests_of_module() {
    MODULE_NAME=$1

    echo "================================================================"
    echo "COMPILING ALL TESTS OF MODULE: '$MODULE_NAME'."
    echo " "

    TEST_PATH_LIST_PATH="$REPOSITORY_FOLDER/$MODULE_NAME/build-config/tests.txt"
    if [[ ! -f $TEST_PATH_LIST_PATH ]]
    then
        echo "Couldn't find list of tests for module '$MODULE_NAME'. Skipping."
        return
    fi

    for RELATIVE_TEST_PATH in $(cat $TEST_PATH_LIST_PATH)
    do
        TEST_PATH=$REPOSITORY_FOLDER/$MODULE_NAME/$RELATIVE_TEST_PATH
        compile_single_test $TEST_PATH
    done
}

function compile_all_tests_of_all_modules() {
    if [[ ! -f "build-config/modules.txt" ]]
    then
        echo "Failed compiling tests: Couldn't find 'build-config/modules.txt"
        return
    fi

    for MODULE in $(cat "build-config/modules.txt")
    do
        compile_all_tests_of_module $MODULE
    done
}

function compile_all_sources_of_all_modules() {
    if [[ ! -f "build-config/modules.txt" ]]
    then
        echo "Failed compiling sources: Couldn't find 'build-config/modules.txt"
        return
    fi

    for MODULE in $(cat "build-config/modules.txt")
    do
        compile_module_c_sources $MODULE
    done
}

function build_in_debug_profile {
    echo "================ Building in Debug Profile! ================"
    CC_OPTIONS=$DEBUG_CC_OPTIONS
    compile_all_sources_of_all_modules
}

function build_in_release_profile {
    echo "================ Building in Release Profile! ================"
    CC_OPTIONS=$RELEASE_CC_OPTIONS
    compile_all_sources_of_all_modules
}

function link_modules {
    
    gcc -o mach.elf .build/*.a .build/*.a
}

case $1 in
    "d" | "dbg" | "debug")
        build_in_debug_profile 
        link_modules
        ;;

    "r" | "release")
        build_in_release_profile 
        link_modules
        ;;
    
    "c" | "clone-dependencies")
        clone_dependencies 
        ;;
    
    "b" | "build-dependencies")
        build_dependencies
        ;;
    "t" | "build-tests")
        compile_all_tests_of_all_modules
        ;;
    "h" | "help")
        echo "Known Actions:"
        echo "[ d | dbg | debug ]:        Build in the debug profile; build with debug symbols."
        echo "[ r | release ]:            Build for a release, with speed optimizations."
        echo "[ c | clone-dependencies]:  Clone the dependencies using Git (network required)."
        echo "[ b | build-dependencies]:  Build the dependencies (which must have been cloned first!)."
        echo "[ h | help ]:               Display this message."
        echo ""
        echo "Note: Before being able to build (debug-profile / release-profile), cloning and building the dependencies is required!"
        ;;
    *)
        echo "Unknown action, try '$0 help' or '$0 h'."
        ;;
esac