//! Scenes: the title screen, characters and their saves, the name forge,
//! derelicts to board, flight (around a place, across the system map, and
//! between systems on the star map), and what's on the ground: cities to
//! walk, and ports.

pub mod aboard;
pub mod character;
pub mod derelict;
pub mod flight;
pub mod forge;
pub mod galaxy_map;
pub mod inventory;
pub mod keys;
pub mod pause;
pub mod port;
pub mod saves;
pub mod sky;
pub mod system_map;
pub mod title;
pub mod town;
#[cfg(test)]
mod zz_dump;

use ratatui::Frame;
use ratatui::crossterm::event::KeyEvent;

use crate::app::Ctx;

/// What a scene wants to happen after it handles a key or a tick.
pub enum Transition {
    None,
    /// Open a scene on top of this one. Popping it comes back here.
    Push(Box<dyn Scene>),
    /// Open several scenes at once, each on top of the one before.
    Open(Vec<Box<dyn Scene>>),
    /// Close this scene and return to the one beneath it.
    Pop,
    /// Close this scene and open these in its place.
    Replace(Vec<Box<dyn Scene>>),
    /// Close every scene but the title screen, at the bottom of the stack.
    Title,
    Quit,
}

/// One screen of the game. The game keeps a stack of them; only the top one
/// gets keys and ticks and is drawn.
pub trait Scene {
    /// A key was pressed, or auto-repeated while held.
    fn key(&mut self, key: KeyEvent, ctx: &mut Ctx) -> Transition;

    /// One fixed step of game time; there are `app::TICKS_PER_SECOND` of
    /// these a second, whatever the frame rate. Turn-based scenes can ignore it.
    fn tick(&mut self, _ctx: &mut Ctx) -> Transition {
        Transition::None
    }

    fn render(&self, frame: &mut Frame, ctx: &Ctx);

    /// This scene has come to the top of the stack: just opened, or
    /// uncovered when the ones above it closed. What it shows may need
    /// bringing up to date with what happened up there.
    fn on_top(&mut self, _ctx: &Ctx) {}
}

#[cfg(test)]
pub(crate) mod tests {
    use ratatui::Terminal;
    use ratatui::backend::TestBackend;
    use ratatui::crossterm::event::{KeyCode, KeyModifiers};

    use super::*;
    use crate::term::KeyboardCaps;

    pub fn test_ctx() -> Ctx {
        Ctx::new(1, KeyboardCaps { key_release: false })
    }

    /// Draws every scene at several sizes, down to absurdly small ones, to
    /// catch layout arithmetic that panics.
    #[test]
    fn scenes_render_at_any_size() {
        let mut ctx = test_ctx();
        let esc = KeyEvent::new(KeyCode::Esc, KeyModifiers::NONE);
        let mut pausing = derelict::Derelict::new(2);
        pausing.key(esc, &mut ctx);
        let mut abandoning = derelict::Derelict::new(2);
        abandoning.key(esc, &mut ctx);
        abandoning.key(KeyEvent::new(KeyCode::Char('2'), KeyModifiers::NONE), &mut ctx);
        let mut aiming = derelict::Derelict::new(2);
        aiming.key(KeyEvent::new(KeyCode::Char('f'), KeyModifiers::NONE), &mut ctx);
        aiming.key(KeyEvent::new(KeyCode::Char('l'), KeyModifiers::NONE), &mut ctx);
        let mut packing = derelict::Derelict::new(2);
        packing.key(KeyEvent::new(KeyCode::Char('i'), KeyModifiers::NONE), &mut ctx);
        // Something of every kind, on you and in the lockers.
        {
            use crate::dungeon::armour;
            use crate::dungeon::arms::Source;
            use crate::items::{Food, Item, Salvage, Slot, Stack};
            let mut rng = crate::seed::rng(8);
            let mut armor = |slot| {
                let mut a = armour::find(&mut rng, Source::Armoury, false);
                a.slot = slot;
                a.durability = 1;
                a
            };
            let food = Food {
                title: "ration brick".into(),
                description: "dense and grey".into(),
                nourishment: 10,
                mass: 400,
            };
            let scrap = Salvage { title: "coil of superconductor".into(), value: 30, mass: 6000 };
            let g = &mut ctx.hold.gear;
            g.worn.insert(Slot::Body, armor(Slot::Body));
            g.add(Stack::one(Item::Armor(armor(Slot::Head))));
            g.add(Stack { item: Item::Food(food), count: 3 });
            g.add(Stack { item: Item::Medpatch, count: 2 });
            ctx.hold.lockers.push(Stack { item: Item::Salvage(scrap.clone()), count: 4 });
            ctx.hold.deck.push((crate::dungeon::Pos::new(0, 0), Stack::one(Item::Salvage(scrap))));
        }
        let mut rummaging = derelict::Derelict::board(2, &mut ctx);
        for code in [KeyCode::Char('i'), KeyCode::Char('j'), KeyCode::Enter] {
            rummaging.key(KeyEvent::new(code, KeyModifiers::NONE), &mut ctx);
        }
        let home = ctx.system.home_place();
        let mut stowing = aboard::Aboard::landed(&ctx, home);
        for code in [KeyCode::Char('i'), KeyCode::Char('l'), KeyCode::Char('/')] {
            stowing.key(KeyEvent::new(code, KeyModifiers::NONE), &mut ctx);
        }
        let mut strolling = town::TownScene::new(&ctx, home);
        strolling.key(KeyEvent::new(KeyCode::Char('i'), KeyModifiers::NONE), &mut ctx);
        let mut leaving = town::TownScene::new(&ctx, home);
        leaving.key(esc, &mut ctx);
        let mut resting = aboard::Aboard::landed(&ctx, home);
        resting.key(esc, &mut ctx);
        let mut flying = flight::FlightScene::new(&ctx);
        flying.key(KeyEvent::new(KeyCode::Tab, KeyModifiers::NONE), &mut ctx);
        let mut holding = flight::FlightScene::new(&ctx);
        holding.key(esc, &mut ctx);
        let mut docked = port::Port::new(&ctx, 0);
        docked.key(esc, &mut ctx);
        let belt = ctx.system.places.len() - 1;
        let mut trading = town::TownScene::new(&ctx, home);
        for _ in 0..12 {
            trading.key(KeyEvent::new(KeyCode::Right, KeyModifiers::NONE), &mut ctx);
        }
        let wreck = ctx.system.wrecks_on(ctx.day).pop();
        let mut renaming = character::Sheet::new();
        renaming.key(KeyEvent::new(KeyCode::Char('r'), KeyModifiers::NONE), &mut ctx);
        let mut creating = character::Create::new(&ctx);
        creating.key(KeyEvent::new(KeyCode::Down, KeyModifiers::NONE), &mut ctx);
        let dir = crate::save::scratch("render");
        ctx.saves = Some(dir.clone());
        ctx.slot = Some(crate::save::new_slot(&dir, &ctx.character, ctx.seed));
        ctx.record.slain.insert("rust-mite".into(), 2);
        ctx.bestiary.insert(("rust-mite", crate::dungeon::arms::Dmg::Blunt));
        ctx.autosave();
        std::fs::write(dir.join("broken.json"), "{").unwrap();
        let playing = title::Title::new(&ctx);
        let mut plotting = galaxy_map::GalaxyMap::new(&ctx);
        plotting.key(KeyEvent::new(KeyCode::Tab, KeyModifiers::NONE), &mut ctx);
        let mut far = galaxy_map::GalaxyMap::new(&ctx);
        for _ in 0..6 {
            far.key(KeyEvent::new(KeyCode::Left, KeyModifiers::NONE), &mut ctx);
        }
        let mut stranded = test_ctx();
        let dead = (0..stranded.galaxy.sites.len())
            .find(|&i| !stranded.galaxy.sites[i].kind.sells_fuel())
            .unwrap();
        stranded.enter_system(dead);
        stranded.hold.fuel = 0;
        stranded.hold.debt = 120;
        let scenes: [Box<dyn Scene>; 33] = [
            Box::new(title::Title::new(&test_ctx())),
            Box::new(playing),
            Box::new(character::Create::new(&ctx)),
            Box::new(creating),
            Box::new(character::Sheet::new()),
            Box::new(renaming),
            Box::new(saves::Saves::new(&ctx)),
            Box::new(forge::Forge::new(&ctx)),
            Box::new(derelict::Derelict::new(1)),
            Box::new(pausing),
            Box::new(abandoning),
            Box::new(holding),
            Box::new(docked),
            Box::new(leaving),
            Box::new(resting),
            Box::new(aiming),
            Box::new(packing),
            Box::new(rummaging),
            Box::new(stowing),
            Box::new(strolling),
            Box::new(flying),
            Box::new(system_map::SystemMap::new(&ctx)),
            Box::new(galaxy_map::GalaxyMap::new(&ctx)),
            Box::new(plotting),
            Box::new(far),
            Box::new(port::Port::new(&ctx, ctx.system.home_place())),
            Box::new(port::Port::new(&ctx, belt)),
            Box::new(port::Port::new(&ctx, 0)),
            Box::new(town::TownScene::new(&ctx, home)),
            Box::new(trading),
            Box::new(aboard::Aboard::landed(&ctx, home)),
            Box::new(aboard::Aboard::resumed(&ctx, home)),
            Box::new(aboard::Aboard::adrift("in orbit around nowhere", wreck)),
        ];
        for (width, height) in [(160, 50), (80, 24), (40, 12), (5, 3), (1, 1)] {
            let mut terminal = Terminal::new(TestBackend::new(width, height)).unwrap();
            for scene in &scenes {
                for ticks in [0, 12_345] {
                    ctx.ticks = ticks;
                    terminal.draw(|frame| scene.render(frame, &ctx)).unwrap();
                }
            }
            let map = galaxy_map::GalaxyMap::new(&stranded);
            terminal.draw(|frame| map.render(frame, &stranded)).unwrap();
        }
        let _ = std::fs::remove_dir_all(dir);
    }
}