# In CMake, this is a comment

# To run our code, please perform the following commands:
#  - mkdir build && cd build
#  - cmake ..
#  - make
# 
# With those steps, we will follow the best practice to compile into a subdir
# and the second line will request to CMake to generate a new OS-dependent
# Makefile. Finally, run the native Make command.

#------------------------------------------------------------------------------
# Basic
#------------------------------------------------------------------------------
#
# The CMake file MUST be named as "CMakeLists.txt".

# Setup the minimum version required of CMake to generate the Makefile
cmake_minimum_required (VERSION 2.8)

# Raises a FATAL_ERROR if version < 2.8
cmake_minimum_required (VERSION 2.8 FATAL_ERROR)

# We define the name of our project, and this changes some directories
# naming convention generated by CMake. We can send the LANG of code
# as the second param
project (learncmake C)

# Set the project source dir (just convention)
set( LEARN_CMAKE_SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR} )
set( LEARN_CMAKE_BINARY_DIR ${CMAKE_CURRENT_BINARY_DIR} )

# It's useful to set up the current version of our code in the build system
# using a `semver` style
set (LEARN_CMAKE_VERSION_MAJOR 1)
set (LEARN_CMAKE_VERSION_MINOR 0)
set (LEARN_CMAKE_VERSION_PATCH 0)

# Send the variables (version number) to the source code header
configure_file (
  "${PROJECT_SOURCE_DIR}/TutorialConfig.h.in"
  "${PROJECT_BINARY_DIR}/TutorialConfig.h"
)

# Include Directories
# In GCC, this will invoke the "-I" command
include_directories( include )

# Where are the additional libraries installed? Note: provide includes
# path here, subsequent checks will resolve everything else
set( CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${CMAKE_SOURCE_DIR}/CMake/modules/" )

# Conditions
if ( CONDITION )
  # Output!

  # Incidental information
  message(STATUS "My message")

  # CMake Warning, continue processing
  message(WARNING "My message")

  # CMake Warning (dev), continue processing
  message(AUTHOR_WARNING "My message")

  # CMake Error, continue processing, but skip generation
  message(SEND_ERROR "My message")

  # CMake Error, stop processing and generation
  message(FATAL_ERROR "My message")
endif()

if( CONDITION )

elseif( CONDITION )

else( CONDITION )

endif( CONDITION )

# Loops
foreach(loop_var arg1 arg2 ...)
  COMMAND1(ARGS ...)
  COMMAND2(ARGS ...)
  ...
endforeach(loop_var)

foreach(loop_var RANGE total)
foreach(loop_var RANGE start stop [step])

foreach(loop_var IN [LISTS [list1 [...]]]
                    [ITEMS [item1 [...]]])

while(condition)
  COMMAND1(ARGS ...)
  COMMAND2(ARGS ...)
  ...
endwhile(condition)


# Logic Operations
if(FALSE AND (FALSE OR TRUE))
  message("Don't display!")
endif()

# Set a regular, cache, or environment variable to a given value.
# If the PARENT_SCOPE option is given, the variable will be set in the scope
# above the current scope.
# `set(<variable> <value>... [PARENT_SCOPE])`

# How to reference variables inside quoted and unquoted arguments?
# A variable reference is replaced by either the variable value or by the 
# empty string if the variable is not set.
${variable_name}

# Lists
# Setup the list of source files
set( LEARN_CMAKE_SOURCES 
  src/main.c
  src/imagem.c
  src/pather.c
)

# Calls the compiler
#
# ${PROJECT_NAME} refers to Learn_CMake 
add_executable( ${PROJECT_NAME} ${LEARN_CMAKE_SOURCES} )

# Link the libraries
target_link_libraries( ${PROJECT_NAME} ${LIBS} m )

# Where are the additional libraries installed? Note: provide includes
# path here, subsequent checks will resolve everything else
set( CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${CMAKE_SOURCE_DIR}/CMake/modules/" )

# Compiler Condition (gcc ; g++)
if ( "${CMAKE_C_COMPILER_ID}" STREQUAL "GNU" )
  message( STATUS "Setting the flags for ${CMAKE_C_COMPILER_ID} compiler" )
  add_definitions( --std=c99 )
endif()

# Check for OS
if( UNIX )
    set( LEARN_CMAKE_DEFINITIONS
        "${LEARN_CMAKE_DEFINITIONS} -Wall -Wextra -Werror -Wno-deprecated-declarations -Wno-unused-parameter -Wno-comment" )
endif()