-module(main).
-behaviour(application).
-export([start/2, stop/1, setup/0]).
%% @doc Initialize Mnesia database schema and tables.
%%
%% Creates a fresh Mnesia schema with four tables for content-addressed storage:
%% <ul>
%% <li>`attribute' - Hash → Value mapping for deduplication</li>
%% <li>`tuple' - Hash → Tuple mapping with attribute references</li>
%% <li>`relation' - Hash → Relation with merkle tree and schema</li>
%% <li>`database_state' - Hash → Database with relation merkle tree</li>
%% </ul>
%%
%% <b>Warning:</b> This function deletes any existing schema and recreates it from scratch.
%%
%% @returns `ok' on success
%% @see operations:create_database/1
setup() ->
mnesia:stop(),
mnesia:delete_schema([node()]),
mnesia:create_schema([node()]),
mnesia:start(),
mnesia:create_table(attribute, [
{attributes, [hash, value]},
{disc_copies, [node()]},
{type, set}
]),
mnesia:create_table(tuple, [
{attributes, [hash, relation, attribute_map]},
{disc_copies, [node()]},
{type, set}
]),
mnesia:create_table(relation, [
{attributes, [hash, name, tree, schema, constraints, cardinality, generator, membership_criteria, mutability, provenance, lineage]},
{disc_copies, [node()]},
{type, set},
{index, [name]} % Index on name for efficient lookup
]),
mnesia:create_table(database_state, [
{attributes, [hash, name, tree, relations, timestamp]},
{disc_copies, [node()]},
{type, set}
]).
uuid() ->
ok = application:load(quickrand),
ok = quickrand:seed(),
ok = quickrand_cache:init(),
quickrand_cache:new().
start(_StartType, _StartArgs) ->
%% Start Mnesia (or other children) here
io:format("Starting app...~n"),
%% Ensure Mnesia is started
mnesia:start(),
setup(),
_ = uuid(),
{ok, self()}.
stop(_State) ->
io:format("Stopping app...~n"),
ok.
