syntax = "proto3";

package backend_proto;

message Empty {}

// 1-15 reserved for future use; 2047 for errors

message BackendInput {
    reserved 2047;
    oneof value {
        TemplateRequirementsIn template_requirements = 16;
        SchedTimingTodayIn sched_timing_today = 17;
        Empty deck_tree = 18;
        FindCardsIn find_cards = 19;
        BrowserRowsIn browser_rows = 20;
        RenderCardIn render_card = 21;

        PlusOneIn plus_one = 2046; // temporary, for testing
    }
}

message BackendOutput {
    oneof value {
        TemplateRequirementsOut template_requirements = 16;
        SchedTimingTodayOut sched_timing_today = 17;
        DeckTreeOut deck_tree = 18;
        FindCardsOut find_cards = 19;
        BrowserRowsOut browser_rows = 20;
        RenderCardOut render_card = 21;

        PlusOneOut plus_one = 2046; // temporary, for testing

        BackendError error = 2047;
    }
}

message BackendError {
    oneof value {
        InvalidInputError invalid_input = 1;
        TemplateParseError template_parse = 2;
    }
}

message InvalidInputError {
    string info = 1;
}

message PlusOneIn {
    int32 num = 1;
}

message PlusOneOut {
    int32 num = 1;
}

message TemplateParseError {
    string info = 1;
}

message TemplateRequirementsIn {
    repeated string template_front = 1;
    map<string, uint32> field_names_to_ordinals = 2;
}

message TemplateRequirementsOut {
    repeated TemplateRequirement requirements = 1;
}

message TemplateRequirement {
    oneof value {
        TemplateRequirementAll all = 1;
        TemplateRequirementAny any = 2;
        Empty none = 3;
    }
}

message TemplateRequirementAll {
    repeated uint32 ords = 1;
}

message TemplateRequirementAny {
    repeated uint32 ords = 1;
}

message SchedTimingTodayIn {
    int64 created_secs = 1;
    sint32 created_mins_west = 2;
    int64 now_secs = 3;
    sint32 now_mins_west = 4;
    sint32 rollover_hour = 5;
}

message SchedTimingTodayOut {
    uint32 days_elapsed = 1;
    int64 next_day_at = 2;
}

message DeckTreeOut {
    DeckTreeNode top = 1;
}

message DeckTreeNode {
    // the components of a deck, split on ::
    repeated string names = 1;
    int64 deck_id = 2;
    uint32 review_count = 3;
    uint32 learn_count = 4;
    uint32 new_count = 5;
    repeated DeckTreeNode children = 6;
    bool collapsed = 7;
}

message FindCardsIn {
    string search = 1;
}

message FindCardsOut {
    repeated int64 card_ids = 1;
}

message BrowserRowsIn {
    repeated int64 card_ids = 1;
}

message BrowserRowsOut {
    // just sort fields for proof of concept
    repeated string sort_fields = 1;
}

message RenderCardIn {
    string question_template = 1;
    string answer_template = 2;
    map<string,string> fields = 3;
    int32 card_ordinal = 4;
}

message RenderCardOut {
    repeated RenderedTemplateNode question_nodes = 1;
    repeated RenderedTemplateNode answer_nodes = 2;
}

message RenderedTemplateNode {
    oneof value {
        string text = 1;
        RenderedTemplateReplacement replacement = 2;
    }
}

message RenderedTemplateReplacement {
    string field_name = 1;
    string current_text = 2;
    repeated string filters = 3;
}