1 files changed, 111 insertions, 0 deletions
diff --git a/src/lib/builder.lua b/src/lib/builder.lua
new file mode 100644
index 0000000..7390257
--- /dev/null
+++ b/src/lib/builder.lua
@@ -0,0 +1,111 @@
+Builder = {}
+
+function Builder:from_template(path)
+	local builder = {
+		template = loadfile(
+			path,
+			nil,
+			Env.Sandbox {
+				Template = Template
+			}
+		)(),
+		source = Path:new(path),
+	}
+
+	builder.source_directory = builder.source:parent()
+
+	setmetatable(builder, self)
+	self.__index = self
+
+	local argument_template = {
+		strict = true,
+		{ name = "target" },
+		{ name = "template", description = "some description", kind = "property", required = true },
+	};
+
+	for key, value in pairs(builder.template.options) do
+		argument_template[#argument_template + 1] = value
+	end
+
+	local args = require('arg')(argument_template)
+
+	for key, _ in pairs(builder.template.options) do
+		builder.template.arguments[key] = args[key]
+	end
+
+	return builder
+end
+
+function Builder:entries()
+	local entries = {}
+
+	for _, value in ipairs(self.template.files) do
+		entries[#entries + 1] = {
+			path = Path:new(value.path),
+			env = value.env,
+		}
+	end
+
+	for _, value in ipairs(self.template.directories) do
+		for entry in Path:new(value.path):children() do
+			entries[#entries + 1] = {
+				path = entry,
+				env = value.env,
+			}
+		end
+	end
+
+	local i = 1
+	return function()
+		local value = entries[i]
+		i = i + 1
+		return value
+	end
+end
+
+function Builder:build(args)
+	local instance = Instance:new()
+
+	for entry in self:entries() do
+		instance:register(
+			entry.path,
+			entry.path.is_directory and nil or self:process_file(entry)
+		)
+	end
+
+	return instance
+end
+
+function Builder:process_file(file)
+	local f = (self.source_directory / file.path):open("r")
+	local raw = f:read("*all")
+	f:close()
+
+	local content = ''
+
+	for _, split in ipairs(raw:split_into_template_blocks()) do
+		if split.kind == 'text' then
+			content = content .. split.content
+		else
+			local func, err = load(
+				'return ' .. split.content,
+				'macro ' .. tostring(file.path),
+				't',
+				Env.Sandbox(file.env)
+			)
+
+			if err then
+				error(err)
+			end
+
+			local value = func()
+			if type(value) == 'function' then
+				content = content .. tostring(value())
+			else
+				content = content .. tostring(value)
+			end
+		end
+	end
+
+	return content
+end