--
-- make_swift.lua
-- Generate a Swift project makefile.
--

local make = premake.make
local swift = { }

function premake.make_swift(prj)
	local tool = premake.gettool(prj)

	-- build a list of supported target platforms that also includes a generic build
	local platforms = premake.filterplatforms(prj.solution, tool.platforms, "Native")

	_p('# %s project makefile autogenerated by GENie', premake.action.current().shortname)
	_p('')

	_p('.SUFFIXES:') -- Delete the default suffix rules.
	_p('')

	-- set up the environment
	_p('ifndef config')
	_p(1, 'config=%s', _MAKE.esc(premake.getconfigname(prj.solution.configurations[1], platforms[1], true)))
	_p('endif')
	_p('')

	_p('ifndef verbose')
	_p(1, 'SILENT = @')
	_p('endif')
	_p('')

	-- identify the shell type
	_p('SHELLTYPE := msdos')
	_p('ifeq (,$(ComSpec)$(COMSPEC))')
	_p(1, 'SHELLTYPE := posix')
	_p('endif')
	_p('ifeq (/bin,$(findstring /bin,$(SHELL)))')
	_p(1, 'SHELLTYPE := posix')
	_p('endif')
	_p('ifeq (/bin,$(findstring /bin,$(MAKESHELL)))')
	_p(1, 'SHELLTYPE := posix')
	_p('endif')
	_p('')

	_p('ifeq (posix,$(SHELLTYPE))')
	_p(1, 'MKDIR = $(SILENT) mkdir -p "$(1)"')
	_p(1, 'COPY  = $(SILENT) cp -fR "$(1)" "$(2)"')
	_p(1, 'RM    = $(SILENT) rm -f "$(1)"')
	_p('else')
	_p(1, 'MKDIR = $(SILENT) mkdir "$(subst /,\\\\,$(1))" 2> nul || exit 0')
	_p(1, 'COPY  = $(SILENT) copy /Y "$(subst /,\\\\,$(1))" "$(subst /,\\\\,$(2))"')
	_p(1, 'RM    = $(SILENT) del /F "$(subst /,\\\\,$(1))" 2> nul || exit 0')
	_p('endif')
	_p('')

	_p('SWIFTC = %s', tool.swift)
	_p('SWIFTLINK = %s', tool.swiftc)
	_p('DSYMUTIL = %s', tool.dsymutil)
	_p('AR = %s', tool.ar)
	_p('')

	-- write configuration blocks
	for _, platform in ipairs(platforms) do
		for cfg in premake.eachconfig(prj, platform) do
			swift.generate_config(prj, cfg, tool)
		end
	end

	_p('.PHONY: ')
	_p('')
	_p('all: $(WORK_DIRS) $(TARGET)')
	_p('')

	_p('$(WORK_DIRS):')
	_p(1, '$(SILENT) $(call MKDIR,$@)')
	_p('')

	_p('SOURCES := \\')
	for _, file in ipairs(prj.files) do
		if path.isswiftfile(file) then
			_p(1, '%s \\', _MAKE.esc(file))
		end
	end
	_p('')

	local objfiles = {}
	_p('OBJECTS_WITNESS := $(OBJDIR)/build.stamp')
	_p('OBJECTS := \\')
	for _, file in ipairs(prj.files) do
		if path.isswiftfile(file) then
			local objname = _MAKE.esc(swift.objectname(file))
			table.insert(objfiles, objname)
			_p(1, '%s \\', objname)
		end
	end
	_p('')

	swift.file_rules(prj, objfiles)
	swift.linker(prj, tool)
	swift.generate_clean(prj)
end

function swift.objectname(file)
	return path.join("$(OBJDIR)", path.getname(file)..".o")
end

function swift.file_rules(prj, objfiles)
		-- use a witness file per recommendation for handling multiple outputs
		-- see https://www.gnu.org/software/automake/manual/html_node/Multiple-Outputs.html
	_p('$(OBJECTS_WITNESS): $(SOURCES)')
	_p(1, "@rm -f $(OBJDIR)/data.tmp")
	_p(1, "@touch $(OBJDIR)/data.tmp")
	_p(1, "$(SILENT) $(SWIFTC) -frontend -c $(SOURCES) -enable-objc-interop $(SDK) -I $(OUT_DIR) $(SWIFTC_FLAGS) -module-cache-path $(MODULECACHE_DIR) -D SWIFT_PACKAGE $(MODULE_MAPS) -emit-module-doc-path $(OUT_DIR)/$(MODULE_NAME).swiftdoc -module-name $(MODULE_NAME) -emit-module-path $(OUT_DIR)/$(MODULE_NAME).swiftmodule -num-threads 8 %s", table.arglist("-o", objfiles))
	_p(1, "@mv -f $(OBJDIR)/data.tmp $(OBJECTS_WITNESS)")
	_p('')

	-- posix only for now
	_p('$(OBJECTS): $(OBJECTS_WITNESS)')
	_p(1, '@if test -f $@; then :; else \\')
	_p(2, 'rm -f $(OBJECTS_WITNESS); \\')
	_p(2, '$(MAKE) $(AM_MAKEFLAGS) $(OBJECTS_WITNESS); \\')
	_p(1, 'fi')
	_p('')
end

function swift.linker(prj, tool)
	local lddeps = make.list(premake.getlinks(prj, "siblings", "fullpath"))

	if prj.kind == "StaticLib" then
		_p("$(TARGET): $(OBJECTS) %s ", lddeps)
		_p(1, "$(SILENT) $(AR) cr $(AR_FLAGS) $@ $(OBJECTS) %s", (os.is("MacOSX") and " 2>&1 > /dev/null | sed -e '/.o) has no symbols$$/d'" or ""))
	else
		_p("$(TARGET): $(OBJECTS) $(LDDEPS)", lddeps)
		_p(1, "$(SILENT) $(SWIFTLINK) $(SDK) -L $(OUT_DIR) -o $@ $(SWIFTLINK_FLAGS) $(LD_FLAGS) $(OBJECTS)")
		_p("ifdef SYMBOLS")
		_p(1, "$(SILENT) $(DSYMUTIL) $(TARGET) -o $(SYMBOLS)")
		_p("endif")
	end
	_p('')
end

function swift.generate_clean(prj)
	_p('clean:')
	if (not prj.solution.messageskip) or (not table.contains(prj.solution.messageskip, "SkipCleaningMessage")) then
		_p('\t@echo Cleaning %s', prj.name)
	end
	_p('ifeq (posix,$(SHELLTYPE))')
	_p('\t$(SILENT) rm -f  $(TARGET)')
	_p('\t$(SILENT) rm -rf $(OBJDIR)')
	_p('\t$(SILENT) rm -rf $(SYMBOLS)')
	_p('\t$(SILENT) rm -rf $(MODULECACHE_DIR)')
	_p('else')
	_p('\t$(SILENT) if exist $(subst /,\\\\,$(TARGET)) del $(subst /,\\\\,$(TARGET))')
	_p('\t$(SILENT) if exist $(subst /,\\\\,$(OBJDIR)) rmdir /s /q $(subst /,\\\\,$(OBJDIR))')
	_p('\t$(SILENT) if exist $(subst /,\\\\,$(SYMBOLS)) rmdir /s /q $(subst /,\\\\,$(SYMBOLS))')
	_p('\t$(SILENT) if exist $(subst /,\\\\,$(MODULECACHE_DIR)) rmdir /s /q $(subst /,\\\\,$(MODULECACHE_DIR))')
	_p('endif')
	_p('')
end

function swift.generate_config(prj, cfg, tool)
	_p('ifeq ($(config),%s)', _MAKE.esc(cfg.shortname))

	_p(1, "OUT_DIR = %s", cfg.buildtarget.directory)
  _p(1, "MODULECACHE_DIR = $(OUT_DIR)/ModuleCache")
	_p(1, "TARGET = $(OUT_DIR)/%s", _MAKE.esc(cfg.buildtarget.name))
	local objdir = path.join(cfg.objectsdir, prj.name .. ".build")
	_p(1, "OBJDIR = %s", objdir)
	_p(1, "MODULE_NAME = %s", prj.name)
	_p(1, "MODULE_MAPS = %s", make.list(tool.getmodulemaps(cfg)))
	_p(1, "SWIFTC_FLAGS = %s", make.list(tool.getswiftcflags(cfg)))
	_p(1, "SWIFTLINK_FLAGS = %s", make.list(tool.getswiftlinkflags(cfg)))
	_p(1, "AR_FLAGS = %s", make.list(tool.getarchiveflags(cfg, cfg, false)))
	_p(1, "LD_FLAGS = %s", make.list(tool.getldflags(cfg)))
	_p(1, "LDDEPS = %s", make.list(premake.getlinks(cfg, "siblings", "fullpath")))
	if cfg.flags.Symbols then
		_p(1, "SYMBOLS = $(TARGET).dSYM")
	end

	local sdk = tool.get_sdk_path(cfg)
	if sdk then
		_p(1, "TOOLCHAIN_PATH = %s", tool.get_toolchain_path(cfg))
		_p(1, "SDK_PATH = %s", sdk)
		_p(1, "PLATFORM_PATH = %s", tool.get_sdk_platform_path(cfg))
		_p(1, "SDK = -sdk $(SDK_PATH)")
	else
		_p(1, "SDK_PATH =")
		_p(1, "SDK =")
	end

	_p(1,'WORK_DIRS = $(OUT_DIR) $(OBJDIR)')

	_p('endif')
	_p('')
end