# Annotations to gather metadata on `app.nit` projects
module app_annotations

private import parser_util
import modelize
import literal
import semantize
private import annotation

# Metadata associated to an `app.nit` project
class AppProject
	# Pretty name of the resulting application
	var name: String = mainmodule.first_real_mmodule.name is lazy

	# Short project name used in `namespace` and configuration files
	var short_name: String = mainmodule.name.replace("-", "_") is lazy

	# Namespace/package used to identify the application
	var namespace = "org.nitlanguage.{short_name}" is lazy

	# Version of the application
	var version = "0.1"

	# Numerical version code of the application
	var version_code: Int is lazy do

		# Get the date and time (down to the minute) as string
		var gmtime = new Tm.gmtime
		var local_time_s = gmtime.strftime("%y%m%d%H%M")
		return local_time_s.to_i
	end

	# Extra folders where to find platform specific resource files
	var files = new Array[String]

	private var modelbuilder: ModelBuilder
	private var mainmodule: MModule

	init
	do
		var annot = modelbuilder.lookup_annotation_on_modules("app_name", mainmodule)
		if annot != null then
			var val = annot.arg_as_string(modelbuilder)
			if val != null then name = val
		end

		annot = modelbuilder.lookup_annotation_on_modules("app_version", mainmodule)
		if annot != null then version = annot.as_version(modelbuilder)

		annot = modelbuilder.lookup_annotation_on_modules("app_namespace", mainmodule)
		if annot != null then
			var val = annot.arg_as_string(modelbuilder)
			if val != null then namespace = val
		end

		var annots = modelbuilder.collect_annotations_on_modules("app_files", mainmodule)
		for a in annots do files.add_all a.as_relative_paths(modelbuilder)

		modelbuilder.toolcontext.check_errors
	end

	redef fun to_s do return """
name: {{{name}}}
namespace: {{{namespace}}}
version: {{{version}}}"""
end

redef class AAnnotation
	# Returns a version string (example: "1.5.6b42a7c") from an annotation `version(1, 5, git_revision)`.
	#
	# The user can enter as many fields as needed. The call to `git_revision` will be replaced by the short
	# revision number. If the working tree is dirty, it will append another field with "d" for dirty.
	private fun as_version(modelbuilder: ModelBuilder): String
	do
		var version_fields = new Array[Object]

		var args = n_args
		if args.length < 1 then
			modelbuilder.error(self, "Syntax Error: `{name}` expects at least one argument.")
			return ""
		else
			for arg in args do
				var value
				value = arg.as_int
				if value != null then
					version_fields.add value
					continue
				end

				value = arg.as_string
				if value != null then
					version_fields.add value
				end

				value = arg.as_id
				if value == "git_revision" then
					# Get Git short revision
					var proc = new ProcessReader("git", "rev-parse", "--short", "HEAD")
					proc.wait
					if proc.status != 0 then
						# Fallback if this is not a git repository or git bins are missing
						version_fields.add "0"
						modelbuilder.warning(self, "git_revision", "Warning: `git_revision` used outside of a git repository or git binaries not available")
						continue
					end

					var lines = proc.read_all
					var revision = lines.split("\n").first

					# Is it dirty?
					# If not, the return of `git diff --shortstat` is an empty line
					proc = new ProcessReader("git", "diff-index", "--quiet", "HEAD")
					proc.wait
					var dirty = proc.status != 0
					if dirty then revision += ".d"

					version_fields.add revision
					continue
				end

				var format_error = "Syntax Error: `{name}` expects its arguments to be of type Int or a call to `git_revision`."
				modelbuilder.error(self, format_error)
				return ""
			end
		end

		return version_fields.join(".")
	end

	# Parse all arguments as paths relative to the declaring module
	#
	# If no arguments are given, then use the parent directory of the module.
	private fun as_relative_paths(modelbuilder: ModelBuilder): Array[String]
	do
		var paths = new Array[String]

		var file = location.file
		if file == null then return paths

		var args = n_args
		if args.is_empty then
			paths.add file.filename.dirname
		else
			for arg in args do
				var val = arg.as_string
				if val != null then
					paths.add file.filename.dirname/val
				else modelbuilder.error(arg, "Syntax Error: `app_files` expects String literals as arguments.")
			end
		end

		return paths
	end
end