--
-- decoy.module
--

-- SPDX-FileCopyrightText: Copyright (c) 2023-2024 Chris Pressey, Cat's Eye Technologies.
-- This work is distributed under a 2-clause BSD license. For more information, see:
-- SPDX-License-Identifier: LicenseRef-BSD-2-Clause-X-Decoy


local Module = {}


function Module:register_symbol(name, value)
    self.symbols[name] = value
end


function Module:lookup_symbol(name)
    return self.symbols[name]
end


function Module:get_module_name()
    local module_name = self:lookup_symbol("module")
    if module_name ~= nil then
        module_name = module_name:text()
    end
    return module_name
end


function Module:foreach_symbol(f)
    for name, value in pairs(self.symbols) do
        f(name, value)
    end
end

--
-- Extract symbols defined in the native program text
-- and set up externs for them in the module.
--
function Module:populate_from_native(program_text)
    local line
    for line in string.gmatch(program_text, "[^\r\n]+") do
        local definedum = string.match(line, "#_# define (.*)")
        if definedum ~= nil then
            self:register_symbol(definedum, Symbol.new(definedum))
        end
    end
end


Module.is_class_of = function(obj)
    local mt = getmetatable(obj)
    return mt and mt.__index == Module
end

Module.new = function(type, content)
    local self = {
        type = type,
        content = content,
        symbols = {},
    }

    setmetatable(self, {__index = Module})

    return self
end

return Module