local fs = require("nvim-lsp-installer.fs")
local path = require("nvim-lsp-installer.path")

local M = {}

function M.get_server_root_path(server)
    return path.concat { vim.fn.stdpath("data"), "lsp_servers", server }
end

M.Server = {}
M.Server.__index = M.Server

---@class Server
--@param opts table
-- @field name (string)                  The name of the LSP server. This MUST correspond with lspconfig's naming.
--
-- @field root_dir (string)              The root directory of the installation. Most servers will make use of server.get_server_root_path() to produce its root_dir path.
--
-- @field installer (function)           The function that installs the LSP (see the .installers module). The function signature should be `function (server, callback)`, where
--                                       `server` is the Server instance being installed, and `callback` is a function that must be called upon completion. The `callback` function
--                                       has the signature `function (success, result)`, where `success` is a boolean and `result` is of any type (similar to `pcall`).
--
-- @field default_options (table)        The default options to be passed to lspconfig's .setup() function. Each server should provide at least the `cmd` field.
--
-- @field pre_install_check (function)   An optional function to be executed before the installer. This allows ensuring that any prerequisites are fulfilled.
--                                       This could for example be verifying that required build tools are installed.
function M.Server:new(opts)
    return setmetatable({
        name = opts.name,
        _installer = opts.installer,
        _root_dir = opts.root_dir,
        _default_options = opts.default_options,
        _pre_install_check = opts.pre_install_check,
    }, M.Server)
end

function M.Server:setup(opts)
    -- We require the lspconfig server here in order to do it as late as possible.
    -- The reason for this is because once a lspconfig server has been imported, it's
    -- automatically registered with lspconfig and causes it to show up in :LspInfo and whatnot.
    require("lspconfig")[self.name].setup(
        vim.tbl_deep_extend("force", self._default_options, opts)
    )
end

function M.Server:get_default_options()
    return vim.deepcopy(self._default_options)
end

function M.Server:is_installed()
    return fs.dir_exists(self._root_dir)
end

function M.Server:create_root_dir()
    fs.mkdirp(self._root_dir)
end

function M.Server:install()
    if self._pre_install_check then
        self._pre_install_check()
    end

    -- We run uninstall after pre_install_check because we don't want to
    -- unnecessarily uninstall a server should it no longer pass the
    -- pre_install_check.
    self:uninstall()

    self:create_root_dir()

    self._installer(self, function (success, result)
        if not success then
            vim.api.nvim_err_writeln(("Server installation failed for %s. %s"):format(self.name, result))
            pcall(self.uninstall, self)
        else
            print(("Successfully installed %s"):format(self.name))
        end
    end)
end

function M.Server:uninstall()
    fs.rmrf(self._root_dir)
end

return M