########################################################################################################################
# @file FindXilinx.cmake
# @author Andrew D. Zonenberg
# @brief Xilinx ISE toolchain CMake module
########################################################################################################################

########################################################################################################################
# Autodetect Xilinx paths (very hacky for now)

# Find /opt/Xilinx or similar
find_file(XILINX_PARENT NAMES Xilinx PATHS /opt)
if(XILINX_PARENT STREQUAL "XILINX_PARENT-NOTFOUND")
	message(FATAL_ERROR "No Xilinx toolchain installation found")
endif()

# Find /opt/Xilinx/VERSION
# TODO: Figure out a better way of doing this
find_file(XILINX NAMES 14.3 PATHS ${XILINX_PARENT})
if(XILINX STREQUAL "XILINX-NOTFOUND")
	message(FATAL_ERROR "No ISE 14.3 installation found")
endif()
message(STATUS "Found Xilinx toolchain... ${XILINX}")

# Set current OS architecture (TODO: autodetect)
set(XILINX_ARCH lin64)

# Find fuse
find_file(FUSE NAMES fuse PATHS "${XILINX}/ISE_DS/ISE/bin/${XILINX_ARCH}/")
if(FUSE STREQUAL "FUSE-NOTFOUND")
	message(FATAL_ERROR "No Xilinx fuse installation found")
endif()
message(STATUS "Found Xilinx fuse... ${FUSE}")

########################################################################################################################
# Argument parsing helper

macro(xilinx_parse_args _top_level _sources)
	set(${_top_level} FALSE)
	set(${_sources})
	set(_found_sources FALSE)
	set(_found_top_level FALSE)
	foreach(arg ${ARGN})
		if(${arg} STREQUAL "TOP_LEVEL")
			set(_found_top_level TRUE)
		elseif(${arg} STREQUAL "SOURCES")
			set(_found_sources TRUE)
		elseif(${_found_sources})
			list(APPEND ${_sources} ${arg})
		elseif(${_found_top_level})
			if(${_top_level})
				message(FATAL_ERROR "Multiple top-level files specified in xilinx_parse_args")
			else()
				set(${_top_level} ${arg})				
			endif()
		else()
			message(FATAL_ERROR "Unrecognized command ${arg} in xilinx_parse_args")
		endif()
	endforeach()
endmacro()

########################################################################################################################
# ISim executable generation

function(add_isim_executable OUTPUT_FILE )
		
	# Parse args
	xilinx_parse_args(TOP_LEVEL SOURCES ${ARGN})
	
	# Get base name without extension of the top-level module
	get_filename_component(TOPLEVEL_BASENAME ${TOP_LEVEL} NAME_WE )
	
	# Write the .prj file
	set(PRJ_FILE "${CMAKE_CURRENT_BINARY_DIR}/${OUTPUT_FILE}.prj")
	file(WRITE ${PRJ_FILE} "verilog work \"${TOP_LEVEL}\"\n")
	foreach(f ${SOURCES})
		file(APPEND ${PRJ_FILE} "verilog work \"${f}\"\n")
	endforeach()
	file(APPEND ${PRJ_FILE} "verilog work \"${XILINX}/ISE_DS/ISE/verilog/src/glbl.v\"\n")
	
	# Main compile rule
	# TODO: tweak this
	add_custom_target(
		${OUTPUT_FILE} ALL
		COMMAND ${FUSE} ${FUSE_FLAGS} -o ${CMAKE_CURRENT_BINARY_DIR}/${OUTPUT_FILE} -prj ${PRJ_FILE}
				work.${TOPLEVEL_BASENAME} work.glbl > ${CMAKE_CURRENT_BINARY_DIR}/${OUTPUT_FILE}_build.log
				2> ${CMAKE_CURRENT_BINARY_DIR}/${OUTPUT_FILE}_err.log
		DEPENDS ${SOURCES} ${TOP_LEVEL}
		COMMENT "Building ISim executable ${OUTPUT_FILE}..."
	)
	
	# Write the tcl script
	set(TCL_FILE "${CMAKE_CURRENT_BINARY_DIR}/${OUTPUT_FILE}.tcl")
	file(WRITE ${TCL_FILE} "onerror {resume}\n")
	file(APPEND ${TCL_FILE} "wave add /\n")
	file(APPEND ${TCL_FILE} "run 1000 ns;\n")
	file(APPEND ${TCL_FILE} "exit;\n")
	
	# Write the run-test wrapper script
	set(TEST_WRAPPER "${CMAKE_CURRENT_BINARY_DIR}/run${OUTPUT_FILE}.sh")
	file(WRITE ${TEST_WRAPPER} "#!/bin/bash\n")
	file(APPEND ${TEST_WRAPPER} "cd ${CMAKE_CURRENT_BINARY_DIR}\n")
	file(APPEND ${TEST_WRAPPER} "source ${XILINX}/ISE_DS/settings64.sh\n")
	file(APPEND ${TEST_WRAPPER} "./${OUTPUT_FILE} -tclbatch ${TCL_FILE} -intstyle silent -vcdfile ${OUTPUT_FILE}.vcd -vcdunit ps || exit 1\n")
	file(APPEND ${TEST_WRAPPER} "cat isim.log | grep -q FAIL\n")
	file(APPEND ${TEST_WRAPPER} "if [ \"$?\" != \"1\" ]; then\n")
	file(APPEND ${TEST_WRAPPER} "    exit 1;\n")
	file(APPEND ${TEST_WRAPPER} "fi\n")
	add_custom_command(TARGET ${OUTPUT_FILE} POST_BUILD COMMAND chmod +x ${TEST_WRAPPER})
	
endfunction()

########################################################################################################################
# Test generation
#
# Usage:
# add_isim_test(NandGate
#	TOP_LEVEL
#		${CMAKE_CURRENT_SOURCE_DIR}/testNandGate.v
#	SOURCES 
#		${CMAKE_SOURCE_DIR}/hdl/NandGate.v
#	)

function(add_isim_test TEST_NAME)

	# Parse args
	xilinx_parse_args(TOP_LEVEL SOURCES ${ARGN})

	# Add the sim executable
	add_isim_executable(test${TEST_NAME}
		TOP_LEVEL
			${TOP_LEVEL}
		SOURCES 
			${SOURCES}
		)

	add_test(${TEST_NAME}
		"${CMAKE_CURRENT_BINARY_DIR}/runtest${TEST_NAME}.sh")
	set_property(TEST ${TEST_NAME} APPEND PROPERTY DEPENDS test${TEST_NAME})


endfunction()