//! The "You" hub — Profile · Stats · Achievements · Replays folded
//! into one tabbed modal (Phase E of `docs/ui-redesign-2026-07.md`).
//!
//! The four screens were previously standalone modals reached one at a
//! time through the HUD popover. The hub owns the modal shell (header,
//! tab chips via the shared [`spawn_tab_chip`] widget, a single Done
//! button); each tab's content is a body builder that lives in its
//! original plugin (`spawn_profile_body`, `spawn_stats_body`,
//! `spawn_achievements_body`, `spawn_replays_body`) so every marker
//! component and per-row update system keeps working unchanged.
//!
//! Legacy screen markers (`ProfileScreen`, `StatsScreen`,
//! `AchievementsScreen`) are inserted on the hub scrim while their tab
//! is active, so existing queries and tests keep their meaning.
//!
//! Open paths: `ToggleProfileRequestEvent` / `ToggleStatsRequestEvent`
//! / `ToggleAchievementsRequestEvent` (HUD popover) and the P / S / A
//! accelerators — each opens the hub pre-selected to its tab, toggles
//! the hub closed when its tab is already showing, or switches tabs
//! when a different tab is showing. Esc, Done, and scrim-click close.

use bevy::ecs::system::SystemParam;
use bevy::prelude::*;

use solitaire_data::StatsSnapshot;

use crate::achievement_plugin::{AchievementsResource, AchievementsScreen};
use crate::events::{
    ToggleAchievementsRequestEvent, ToggleProfileRequestEvent, ToggleStatsRequestEvent,
};
use crate::font_plugin::FontResource;
use crate::profile_plugin::{AvatarResource, ProfileScreen};
use crate::progress_plugin::ProgressResource;
use crate::resources::SyncStatusResource;
use crate::settings_plugin::SettingsResource;
use crate::stats_plugin::{ReplayHistoryResource, SelectedReplayIndex, StatsResource, StatsScreen};
use crate::time_attack_plugin::TimeAttackResource;
use crate::ui_focus::FocusRow;
use crate::ui_modal::{
    ButtonVariant, ModalScrim, ScrimDismissible, spawn_modal, spawn_modal_actions,
    spawn_modal_button, spawn_modal_header, spawn_tab_chip,
};
use crate::ui_theme::{VAL_SPACE_2, VAL_SPACE_3, Z_MODAL_PANEL};

/// Which tab of the You hub is showing.
#[derive(Debug, Clone, Copy, PartialEq, Eq, Default)]
pub enum YouTab {
    #[default]
    Profile,
    Stats,
    Achievements,
    Replays,
}

impl YouTab {
    /// Every tab, in display order.
    pub const ALL: [Self; 4] = [
        Self::Profile,
        Self::Stats,
        Self::Achievements,
        Self::Replays,
    ];

    /// Chip label.
    pub fn label(self) -> &'static str {
        match self {
            Self::Profile => "Profile",
            Self::Stats => "Stats",
            Self::Achievements => "Awards",
            Self::Replays => "Replays",
        }
    }
}

/// The active hub tab. Session-only; reopening returns to the last tab
/// unless an open request names a different one.
#[derive(Resource, Debug, Default)]
pub struct ActiveYouTab(pub YouTab);

/// Marker on the hub modal's scrim root.
#[derive(Component)]
pub struct YouHubScreen;

/// Per-chip tab selector button.
#[derive(Component, Debug)]
struct YouHubTabButton(YouTab);

/// Marker on the hub's Done button.
#[derive(Component)]
struct YouHubCloseButton;

/// Read-only bundle of everything the tab bodies render from. Split
/// out as a [`SystemParam`] because the open + rebuild systems both
/// need the full set and Bevy caps systems at 16 parameters.
#[derive(SystemParam)]
struct YouHubContext<'w> {
    settings: Option<Res<'w, SettingsResource>>,
    sync_status: Option<Res<'w, SyncStatusResource>>,
    progress: Option<Res<'w, ProgressResource>>,
    achievements: Option<Res<'w, AchievementsResource>>,
    stats: Option<Res<'w, StatsResource>>,
    avatar: Option<Res<'w, AvatarResource>>,
    time_attack: Option<Res<'w, TimeAttackResource>>,
    replay_history: Option<Res<'w, ReplayHistoryResource>>,
    selected_replay: Option<Res<'w, SelectedReplayIndex>>,
    font_res: Option<Res<'w, FontResource>>,
}

/// Bevy plugin owning the You hub lifecycle. Requires the profile,
/// stats, and achievement plugins for live data; degrades to empty tab
/// bodies without them (headless tests).
pub struct YouHubPlugin;

impl Plugin for YouHubPlugin {
    fn build(&self, app: &mut App) {
        app.init_resource::<ActiveYouTab>()
            .add_message::<ToggleProfileRequestEvent>()
            .add_message::<ToggleStatsRequestEvent>()
            .add_message::<ToggleAchievementsRequestEvent>()
            .add_systems(
                Update,
                // Chained: a toggle/chip press must be observed before
                // the rebuild, and the rebuild before close — total
                // order prevents double-spawns within one frame.
                (
                    open_or_toggle_you_hub,
                    handle_tab_buttons,
                    rebuild_on_tab_change,
                    handle_close_button,
                )
                    .chain(),
            );
    }
}

/// Maps this frame's toggle events + accelerator keys to a requested
/// tab, mirroring the semantics the three standalone screens had.
fn requested_tab(
    profile_events: &mut MessageReader<ToggleProfileRequestEvent>,
    stats_events: &mut MessageReader<ToggleStatsRequestEvent>,
    achievements_events: &mut MessageReader<ToggleAchievementsRequestEvent>,
    keys: &ButtonInput<KeyCode>,
) -> Option<YouTab> {
    let profile = profile_events.read().count() > 0 || keys.just_pressed(KeyCode::KeyP);
    let stats = stats_events.read().count() > 0 || keys.just_pressed(KeyCode::KeyS);
    let achievements = achievements_events.read().count() > 0 || keys.just_pressed(KeyCode::KeyA);
    if profile {
        Some(YouTab::Profile)
    } else if stats {
        Some(YouTab::Stats)
    } else if achievements {
        Some(YouTab::Achievements)
    } else {
        None
    }
}

/// Opens the hub on the requested tab, switches tabs when it's already
/// open on a different one, toggles it closed on a same-tab request or
/// Esc.
#[allow(clippy::too_many_arguments)]
fn open_or_toggle_you_hub(
    mut commands: Commands,
    keys: Res<ButtonInput<KeyCode>>,
    mut profile_events: MessageReader<ToggleProfileRequestEvent>,
    mut stats_events: MessageReader<ToggleStatsRequestEvent>,
    mut achievements_events: MessageReader<ToggleAchievementsRequestEvent>,
    screens: Query<Entity, With<YouHubScreen>>,
    other_modal_scrims: Query<(), (With<ModalScrim>, Without<YouHubScreen>)>,
    mut active: ResMut<ActiveYouTab>,
    ctx: YouHubContext,
) {
    let requested = requested_tab(
        &mut profile_events,
        &mut stats_events,
        &mut achievements_events,
        &keys,
    );
    let open = !screens.is_empty();

    if open {
        // Esc closes the topmost modal — the hub, when it's showing.
        if keys.just_pressed(KeyCode::Escape) {
            for entity in &screens {
                commands.entity(entity).despawn();
            }
            return;
        }
        match requested {
            Some(tab) if tab == active.0 => {
                // Same-tab request toggles closed (P opens Profile,
                // P again closes — parity with the old screens).
                for entity in &screens {
                    commands.entity(entity).despawn();
                }
            }
            Some(tab) => {
                // Different tab: switch in place. The rebuild system
                // (next in the chain) observes the change.
                active.0 = tab;
            }
            None => {}
        }
        return;
    }

    let Some(tab) = requested else { return };
    if !other_modal_scrims.is_empty() {
        return; // Another modal is already visible (§14.2).
    }
    if active.0 != tab {
        // Written before the spawn; the rebuild system also runs this
        // frame but sees no live hub (the spawn below is deferred), so
        // no double-spawn.
        active.0 = tab;
    }
    spawn_you_hub(&mut commands, tab, &ctx);
}

/// Switches the active tab when a chip is pressed.
fn handle_tab_buttons(
    interactions: Query<(&Interaction, &YouHubTabButton), Changed<Interaction>>,
    mut active: ResMut<ActiveYouTab>,
) {
    for (interaction, chip) in &interactions {
        if *interaction != Interaction::Pressed {
            continue;
        }
        if active.0 != chip.0 {
            active.0 = chip.0;
        }
    }
}

/// Rebuilds the open hub when [`ActiveYouTab`] changes.
fn rebuild_on_tab_change(
    active: Res<ActiveYouTab>,
    screens: Query<Entity, With<YouHubScreen>>,
    mut commands: Commands,
    ctx: YouHubContext,
) {
    if !active.is_changed() || active.is_added() {
        return;
    }
    if screens.is_empty() {
        return;
    }
    for entity in &screens {
        commands.entity(entity).despawn();
    }
    spawn_you_hub(&mut commands, active.0, &ctx);
}

/// Despawns the hub when Done is pressed.
fn handle_close_button(
    interactions: Query<&Interaction, (Changed<Interaction>, With<YouHubCloseButton>)>,
    screens: Query<Entity, With<YouHubScreen>>,
    mut commands: Commands,
) {
    for interaction in &interactions {
        if *interaction != Interaction::Pressed {
            continue;
        }
        for entity in &screens {
            commands.entity(entity).despawn();
        }
    }
}

/// Spawns the hub modal showing `tab`, and stamps the scrim with the
/// tab's legacy screen marker so pre-hub queries keep working.
fn spawn_you_hub(commands: &mut Commands, tab: YouTab, ctx: &YouHubContext) {
    let font_res = ctx.font_res.as_deref();
    let scrim = spawn_modal(commands, YouHubScreen, Z_MODAL_PANEL, |card| {
        spawn_modal_header(card, "You", font_res);

        // Tab chips — shared widget with the Settings panel.
        card.spawn((
            FocusRow,
            Node {
                flex_direction: FlexDirection::Row,
                flex_wrap: FlexWrap::Wrap,
                column_gap: VAL_SPACE_2,
                row_gap: VAL_SPACE_2,
                margin: UiRect::bottom(VAL_SPACE_3),
                ..default()
            },
        ))
        .with_children(|row| {
            for chip_tab in YouTab::ALL {
                spawn_tab_chip(
                    row,
                    YouHubTabButton(chip_tab),
                    chip_tab.label(),
                    chip_tab == tab,
                    font_res,
                );
            }
        });

        match tab {
            YouTab::Profile => crate::profile_plugin::spawn_profile_body(
                card,
                ctx.settings.as_deref(),
                ctx.sync_status.as_deref(),
                ctx.progress.as_deref(),
                ctx.achievements.as_deref(),
                ctx.stats.as_deref(),
                font_res,
                ctx.avatar.as_deref(),
            ),
            YouTab::Stats => {
                let default_stats = StatsSnapshot::default();
                crate::stats_plugin::spawn_stats_body(
                    card,
                    ctx.stats.as_deref().map_or(&default_stats, |s| &s.0),
                    ctx.progress.as_deref().map(|p| &p.0),
                    ctx.time_attack.as_deref(),
                    font_res,
                );
            }
            YouTab::Achievements => crate::achievement_plugin::spawn_achievements_body(
                card,
                ctx.achievements
                    .as_deref()
                    .map_or(&[][..], |a| a.0.as_slice()),
                font_res,
            ),
            YouTab::Replays => crate::stats_plugin::spawn_replays_body(
                card,
                ctx.replay_history
                    .as_deref()
                    .map_or(&[][..], |h| h.0.replays.as_slice()),
                ctx.selected_replay.as_deref().map_or(0, |s| s.0),
                font_res,
            ),
        }

        spawn_modal_actions(card, |actions| {
            spawn_modal_button(
                actions,
                YouHubCloseButton,
                "Done",
                None,
                ButtonVariant::Primary,
                font_res,
            );
        });
    });
    let mut scrim_commands = commands.entity(scrim);
    scrim_commands.insert(ScrimDismissible);
    // Legacy markers: pre-hub code and tests query these.
    match tab {
        YouTab::Profile => {
            scrim_commands.insert(ProfileScreen);
        }
        YouTab::Stats | YouTab::Replays => {
            scrim_commands.insert(StatsScreen);
        }
        YouTab::Achievements => {
            scrim_commands.insert(AchievementsScreen);
        }
    }
}

// ---------------------------------------------------------------------------
// Tests
// ---------------------------------------------------------------------------

#[cfg(test)]
mod tests {
    use super::*;

    fn headless_app() -> App {
        let mut app = App::new();
        app.add_plugins(MinimalPlugins).add_plugins(YouHubPlugin);
        app.init_resource::<ButtonInput<KeyCode>>();
        app.update();
        app
    }

    fn hub_count(app: &mut App) -> usize {
        app.world_mut()
            .query::<&YouHubScreen>()
            .iter(app.world())
            .count()
    }

    /// Each Toggle*RequestEvent opens the hub pre-selected to its tab,
    /// stamped with the tab's legacy screen marker.
    #[test]
    fn toggle_events_open_hub_on_their_tab() {
        use bevy::ecs::message::Messages;

        let mut app = headless_app();
        app.world_mut()
            .resource_mut::<Messages<ToggleStatsRequestEvent>>()
            .write(ToggleStatsRequestEvent);
        app.update();
        app.update();

        assert_eq!(hub_count(&mut app), 1, "stats request must open the hub");
        assert_eq!(app.world().resource::<ActiveYouTab>().0, YouTab::Stats);
        assert_eq!(
            app.world_mut()
                .query::<&StatsScreen>()
                .iter(app.world())
                .count(),
            1,
            "legacy StatsScreen marker must ride the hub scrim"
        );

        // A different tab's request switches in place — still one hub.
        app.world_mut()
            .resource_mut::<Messages<ToggleAchievementsRequestEvent>>()
            .write(ToggleAchievementsRequestEvent);
        app.update();
        app.update();
        assert_eq!(hub_count(&mut app), 1, "tab switch must not stack hubs");
        assert_eq!(
            app.world().resource::<ActiveYouTab>().0,
            YouTab::Achievements
        );
        assert_eq!(
            app.world_mut()
                .query::<&AchievementsScreen>()
                .iter(app.world())
                .count(),
            1
        );

        // Same-tab request toggles the hub closed.
        app.world_mut()
            .resource_mut::<Messages<ToggleAchievementsRequestEvent>>()
            .write(ToggleAchievementsRequestEvent);
        app.update();
        app.update();
        assert_eq!(hub_count(&mut app), 0, "same-tab request must close");
    }

    /// Chip-driven tab switches rebuild the single hub with the new
    /// tab's body (Profile scrollable swaps for the Stats one).
    #[test]
    fn tab_switch_swaps_bodies_without_stacking() {
        use crate::profile_plugin::ProfileScrollable;
        use crate::stats_plugin::StatsScrollable;
        use bevy::ecs::message::Messages;

        let mut app = headless_app();
        app.world_mut()
            .resource_mut::<Messages<ToggleProfileRequestEvent>>()
            .write(ToggleProfileRequestEvent);
        app.update();
        app.update();
        assert_eq!(
            app.world_mut()
                .query::<&ProfileScrollable>()
                .iter(app.world())
                .count(),
            1,
            "profile body must spawn on the Profile tab"
        );

        app.world_mut().resource_mut::<ActiveYouTab>().0 = YouTab::Stats;
        app.update();
        app.update();

        assert_eq!(hub_count(&mut app), 1, "rebuild must not stack scrims");
        assert_eq!(
            app.world_mut()
                .query::<&ProfileScrollable>()
                .iter(app.world())
                .count(),
            0,
            "profile body must despawn when leaving the tab"
        );
        assert_eq!(
            app.world_mut()
                .query::<&StatsScrollable>()
                .iter(app.world())
                .count(),
            1,
            "stats body must spawn on the Stats tab"
        );
    }
}