%% -*- erlang -*-
%% Adds every project markdown extra (including doc_rules/**) to ex_doc so HexDocs
%% resolves links from README / RULES, and groups sidebar entries by category.

%% helper funs
SetOpt = fun(Key, Value, Opts) ->
    lists:keystore(Key, 1, lists:keydelete(Key, 1, Opts), {Key, Value})
end,

InDir = fun(Dir) ->
    fun(F) ->
        lists:prefix(Dir, F)
    end
end,

AsBin = fun(ListOfCharLists) ->
    [list_to_binary(CharList) || CharList <- ListOfCharLists]
end,

RootExtras = [
    "README.md",
    "RULES.md",
    "MIGRATION.md",
    "CHANGELOG.md",
    "CONTRIBUTING.md",
    "SECURITY.md",
    "CODE_OF_CONDUCT.md",
    "LICENSE"
],
DocRuleFiles = lists:sort(filelib:wildcard("doc_rules/**/*.md")),

StyleFiles = lists:filter(InDir("doc_rules/elvis_style/"), DocRuleFiles),
TextStyleFiles = lists:filter(InDir("doc_rules/elvis_text_style/"), DocRuleFiles),
ProjectRuleFiles = lists:filter(InDir("doc_rules/elvis_project/"), DocRuleFiles),
GitignoreFiles = lists:filter(InDir("doc_rules/elvis_gitignore/"), DocRuleFiles),

GroupsForExtras = [
    {<<"Overview">>, AsBin(RootExtras)},
    {<<"Style rules">>, AsBin(StyleFiles)},
    {<<"Text style rules">>, AsBin(TextStyleFiles)},
    {<<"Project rules">>, AsBin(ProjectRuleFiles)},
    {<<"Gitignore rules">>, AsBin(GitignoreFiles)}
],

AllExtras = RootExtras ++ DocRuleFiles,

ExDoc0 = proplists:get_value(ex_doc, CONFIG, []),
ExDoc1 = SetOpt(extras, AllExtras, ExDoc0),
ExDoc2 = SetOpt(groups_for_extras, GroupsForExtras, ExDoc1),

lists:keystore(ex_doc, 1, CONFIG, {ex_doc, ExDoc2}).