nocal/include/nocal/tui/Screen.hpp

#pragma once

#include <chrono>
#include <optional>
#include <span>
#include <string>
#include <string_view>
#include <vector>

#include "nocal/domain/event.hpp"
#include "nocal/domain/event_query.hpp"

namespace nocal::tui {

enum class ItemSegment {
    single,
    start,
    continuation,
    end,
};

// A deliberately small view-model keeps the renderer independent of storage and
// makes it straightforward to unit test. TuiApp adapts domain Events to this.
struct CalendarItem {
    std::string id;
    std::string title;
    std::chrono::year_month_day day;
    std::optional<std::chrono::minutes> time_of_day;
    bool all_day{false};
    std::optional<std::chrono::minutes> end_time_of_day;
    std::chrono::year_month_day start_day{};
    std::chrono::year_month_day end_day{};
    std::string location;
    std::string description;
    std::string detail_title;
    bool detail_all_day{false};
    std::optional<std::chrono::minutes> detail_start_time_of_day;
    ItemSegment segment{ItemSegment::single};
    bool recurring{false};
    std::string recurrence_summary;
    std::string source_time_zone;
};

struct SearchResultItem {
    std::string focus_id;
    std::string title;
    std::chrono::year_month_day day;
    std::optional<std::chrono::minutes> time_of_day;
    bool all_day{false};
    std::string location;
    bool recurring{false};
};

struct AgendaItem {
    std::string focus_id;
    std::string title;
    std::chrono::year_month_day day;
    std::optional<std::chrono::minutes> time_of_day;
    bool all_day{false};
    std::string location;
    std::string calendar_id;
    bool recurring{false};
};

struct ScreenState {
    std::chrono::year_month visible_month{std::chrono::year{1970}, std::chrono::month{1}};
    std::chrono::year_month_day selected_day{std::chrono::year{1970}, std::chrono::month{1},
                                              std::chrono::day{1}};
    std::chrono::year_month_day today{std::chrono::year{1970}, std::chrono::month{1},
                                       std::chrono::day{1}};
    int width{80};
    int height{24};
    bool show_help{false};
    bool ansi{true};
    std::optional<std::string> focused_event_id;
    bool show_event_details{false};
    bool confirm_delete{false};
    bool search_prompt{false};
    bool show_search_results{false};
    std::string search_query;
    std::vector<SearchResultItem> search_results;
    std::size_t search_result_index{0};
    std::string notification;
    bool notification_is_error{false};
    bool show_calendar_picker{false};
    std::size_t calendar_index{0};
    bool show_agenda{false};
    std::chrono::year_month_day agenda_start_day{
        std::chrono::year{1970}, std::chrono::month{1}, std::chrono::day{1}};
    std::vector<AgendaItem> agenda_items;
    std::size_t agenda_index{0};
};

// Render a complete frame. The result contains no cursor positioning, which
// makes it useful both for snapshots and for non-interactive output.
[[nodiscard]] std::string render_month(std::span<const CalendarItem> items,
                                       const ScreenState& state);

// Convenience adapter for the domain model. Occurrence instants are projected
// into the user's process-local zone; the reader retains an explicit source TZID.
[[nodiscard]] std::string render_month(std::span<const Event> events,
                                       const ScreenState& state);

// Calendar visibility filters presentation only. Focus identities are still
// derived from the complete event collection.
[[nodiscard]] std::string render_month(std::span<const Event> events,
                                       std::span<const Calendar> calendars,
                                       const ScreenState& state);

// Stable focus identity shared by the renderer and controller. Non-recurring
// events retain their historical UID/synthetic identity; recurring instances
// additionally include their concrete start instant.
[[nodiscard]] std::string occurrence_focus_id(std::span<const Event> events,
                                              const EventOccurrence& occurrence);

enum class Action {
    none,
    left,
    right,
    up,
    down,
    previous_month,
    next_month,
    today,
    toggle_help,
    previous_event,
    next_event,
    select,
    back,
    add_event,
    edit_event,
    delete_event,
    undo,
    redo,
    search,
    agenda,
    calendars,
    quit,
};

// Decodes a complete key sequence, including common terminal arrow/Page keys.
[[nodiscard]] Action decode_key(std::string_view sequence) noexcept;

} // namespace nocal::tui