-module(fabric).

% DBs
-export([all_dbs/0, all_dbs/1, create_db/2, delete_db/2, get_db_info/1,
    get_doc_count/1]).

% Documents
-export([open_doc/3, open_revs/4, get_missing_revs/2, update_doc/3,
    update_docs/3, att_receiver/2]).

% Views
-export([all_docs/4, changes/4, query_view/3, query_view/4, query_view/6,
    get_view_group_info/2]).

% miscellany
-export([db_path/2, design_docs/1]).

-include("fabric.hrl").

% db operations
-spec db_path(bstring(), bstring()) -> bstring().
db_path(RawUri, Customer) ->
    CustomerUri = generate_customer_path(RawUri, Customer),
    {Path, _, _} = mochiweb_util:urlsplit_path(CustomerUri),
    Path.

all_dbs() ->
    fabric_all_databases:all_databases("").

all_dbs(Customer) ->
    fabric_all_databases:all_databases(Customer).

get_db_info(DbName) ->
    fabric_db_info:go(dbname(DbName)).

get_doc_count(DbName) ->
    fabric_db_doc_count:go(dbname(DbName)).

create_db(DbName, Options) ->
    fabric_db_create:create_db(dbname(DbName), opts(Options)).

delete_db(DbName, Options) ->
    fabric_db_delete:delete_db(dbname(DbName), opts(Options)).


% doc operations
open_doc(DbName, Id, Options) ->
    fabric_doc_open:go(dbname(DbName), docid(Id), opts(Options)).

open_revs(DbName, Id, Revs, Options) ->
    fabric_doc_open_revs:go(dbname(DbName), docid(Id), Revs, opts(Options)).

get_missing_revs(DbName, IdsRevs) when is_list(IdsRevs) ->
    Sanitized = [idrevs(IdR) || IdR <- IdsRevs],
    fabric_doc_missing_revs:go(dbname(DbName), Sanitized).

update_doc(DbName, Doc, Options) ->
    {ok, [Result]} = update_docs(DbName, [Doc], opts(Options)),
    case Result of
    {ok, _} ->
        Result;
    Error ->
        throw(Error)
    end.

update_docs(DbName, Docs, Options) ->
    fabric_doc_update:go(dbname(DbName), docs(Docs), opts(Options)).

att_receiver(Req, Length) ->
    fabric_doc_attachments:receiver(Req, Length).

all_docs(DbName, #view_query_args{} = QueryArgs, Callback, Acc0) when
        is_function(Callback, 2) ->
    fabric_view_all_docs:go(dbname(DbName), QueryArgs, Callback, Acc0).

changes(DbName, Options, Callback, Acc0) ->
    % TODO use a keylist for Options instead of #changes_args, BugzID 10281
    Feed = Options#changes_args.feed,
    fabric_view_changes:go(dbname(DbName), Feed, Options, Callback, Acc0).

query_view(DbName, DesignName, ViewName) ->
    query_view(DbName, DesignName, ViewName, #view_query_args{}).

query_view(DbName, DesignName, ViewName, QueryArgs) ->
    Callback = fun default_callback/2,
    query_view(DbName, DesignName, ViewName, QueryArgs, Callback, []).

query_view(DbName, Design, ViewName, QueryArgs, Callback, Acc0) ->
    Db = dbname(DbName), View = name(ViewName),
    case is_reduce_view(Db, Design, View, QueryArgs) of
    true ->
        Mod = fabric_view_reduce;
    false ->
        Mod = fabric_view_map
    end,
    Mod:go(Db, Design, View, QueryArgs, Callback, Acc0).

get_view_group_info(DbName, DesignId) ->
    fabric_group_info:go(dbname(DbName), name(DesignId)).

design_docs(DbName) ->
    QueryArgs = #view_query_args{start_key = <<"_design/">>, include_docs=true},
    Callback = fun({total_and_offset, _, _}, []) ->
        {ok, []};
    ({row, {Props}}, Acc) ->
        case couch_util:get_value(id, Props) of
        <<"_design/", _/binary>> ->
            {ok, [couch_util:get_value(doc, Props) | Acc]};
        _ ->
            {stop, Acc}
        end;
    (complete, Acc) ->
        {ok, lists:reverse(Acc)}
    end,
    fabric:all_docs(dbname(DbName), QueryArgs, Callback, []).

%% some simple type validation and transcoding

dbname(DbName) when is_list(DbName) ->
    list_to_binary(DbName);
dbname(DbName) when is_binary(DbName) ->
    DbName;
dbname(#db{name=Name}) ->
    Name;
dbname(DbName) ->
    erlang:error({illegal_database_name, DbName}).

name(Thing) ->
    couch_util:to_binary(Thing).

docid(DocId) when is_list(DocId) ->
    list_to_binary(DocId);
docid(DocId) when is_binary(DocId) ->
    DocId;
docid(DocId) ->
    erlang:error({illegal_docid, DocId}).

docs(Docs) when is_list(Docs) ->
    [doc(D) || D <- Docs];
docs(Docs) ->
    erlang:error({illegal_docs_list, Docs}).

doc(#doc{} = Doc) ->
    Doc;
doc({_} = Doc) ->
    couch_doc:from_json_obj(Doc);
doc(Doc) ->
    erlang:error({illegal_doc_format, Doc}).

idrevs({Id, Revs}) when is_list(Revs) ->
    {docid(Id), [rev(R) || R <- Revs]}.

rev(Rev) when is_list(Rev); is_binary(Rev) ->
    couch_doc:parse_rev(Rev);
rev({Seq, Hash} = Rev) when is_integer(Seq), is_binary(Hash) ->
    Rev.

opts(Options) ->
    case couch_util:get_value(user_ctx, Options) of
    undefined ->
        case erlang:get(user_ctx) of
        #user_ctx{} = Ctx ->
            [{user_ctx, Ctx} | Options];
        _ ->
            Options
        end;
    _ ->
        Options
    end.

default_callback(complete, Acc) ->
    {ok, lists:reverse(Acc)};
default_callback(Row, Acc) ->
    {ok, [Row | Acc]}.

is_reduce_view(_, _, _, #view_query_args{view_type=Reduce}) ->
    Reduce =:= reduce.

generate_customer_path("/", _Customer) ->
    "";
generate_customer_path("/favicon.ico", _Customer) ->
    "favicon.ico";
generate_customer_path([$/,$_|Rest], _Customer) ->
    lists:flatten([$_|Rest]);
generate_customer_path([$/|RawPath], Customer) ->
    case Customer of
    "" ->
        RawPath;
    Else ->
        lists:flatten([Else, "%2F", RawPath])
    end.