//! Golden tests for the parser and a full headless play-through of the
//! sample game — the safety net under every future refactor.

use mrpgi_core::ai::AiConfig;
use mrpgi_core::parser::{build_verbs, default_verbs, run_command};
use mrpgi_core::state::{Command, Event};
use mrpgi_core::world::ObjDef;
use mrpgi_core::{GameState, World};
use std::collections::HashMap;

fn obj(name: &str, takeable: bool, needs: &str, use_text: &str, wins: bool) -> ObjDef {
    ObjDef {
        name: name.into(),
        sprite: "sign".into(),
        x: 80,
        y: 100,
        look: format!("It's a {}.", name),
        takeable,
        synonyms: String::new(),
        use_text: use_text.into(),
        needs: needs.into(),
        wins,
        requires_flag: String::new(),
        sets_flag: String::new(),
        dialogue: Vec::new(),
    }
}

/// Run one line against a tiny fixture room; return (first line, understood).
fn run(input: &str, objects: &[ObjDef], inventory: &mut Vec<String>) -> (String, bool) {
    let verbs = default_verbs();
    let mut taken = Vec::new();
    let mut won = false;
    let mut flags = HashMap::new();
    let mut talk = None;
    let (lines, understood) = run_command(input, &verbs, objects, 0, inventory, &mut taken, &mut won, &mut flags, &mut talk);
    (lines.first().cloned().unwrap_or_default(), understood)
}

#[test]
fn parser_goldens() {
    let objects = vec![obj("battery", true, "", "", false), obj("hatch", false, "battery", "It opens!", true)];

    let mut inv = Vec::new();
    assert_eq!(run("look", &objects, &mut inv), ("Room 0. You see: battery, hatch.".into(), true));
    assert_eq!(run("examine the battery", &objects, &mut inv), ("It's a battery.".into(), true));
    assert_eq!(run("grab battery", &objects, &mut inv), ("You take the battery.".into(), true));
    assert_eq!(inv, vec!["battery".to_string()]);
    assert_eq!(run("take hatch", &objects, &mut inv), ("You can't take the hatch.".into(), true));
    assert_eq!(run("i", &objects, &mut inv), ("Carrying: battery.".into(), true));
    assert_eq!(run("drop battery", &objects, &mut inv), ("You drop the battery.".into(), true));
    assert_eq!(run("drop battery", &objects, &mut inv), ("You aren't carrying a 'battery'.".into(), true));
    assert_eq!(run("dance wildly", &objects, &mut inv).1, false);
    assert_eq!(run("talk hatch", &objects, &mut inv), ("hatch has nothing to say.".into(), true));
}

#[test]
fn use_respects_needs_lock() {
    let objects = vec![obj("battery", true, "", "", false), obj("hatch", false, "battery", "It opens!", true)];
    let verbs = default_verbs();
    let mut inv = Vec::new();
    let mut taken = Vec::new();
    let mut won = false;
    let mut flags = HashMap::new();
    let mut talk = None;

    let (lines, _) = run_command("open hatch", &verbs, &objects, 0, &mut inv, &mut taken, &mut won, &mut flags, &mut talk);
    assert_eq!(lines[0], "It's locked. You need: battery.");
    assert!(!won);

    run_command("take battery", &verbs, &objects, 0, &mut inv, &mut taken, &mut won, &mut flags, &mut talk);
    let (lines, _) = run_command("open hatch", &verbs, &objects, 0, &mut inv, &mut taken, &mut won, &mut flags, &mut talk);
    assert_eq!(lines[0], "It opens!");
    assert!(won);
}

#[test]
fn use_respects_flag_gate_and_sets_flags() {
    let mut lever = obj("lever", false, "", "The lever clunks over.", false);
    lever.sets_flag = "power_on".into();
    let mut door = obj("door", false, "", "The door slides open.", true);
    door.requires_flag = "power_on".into();
    let objects = vec![lever, door];

    let verbs = default_verbs();
    let (mut inv, mut taken, mut won, mut flags, mut talk) = (Vec::new(), Vec::new(), false, HashMap::new(), None);

    let (lines, _) = run_command("use door", &verbs, &objects, 0, &mut inv, &mut taken, &mut won, &mut flags, &mut talk);
    assert_eq!(lines[0], "Nothing happens. Something else must come first.");
    assert!(!won);

    run_command("use lever", &verbs, &objects, 0, &mut inv, &mut taken, &mut won, &mut flags, &mut talk);
    assert_eq!(flags.get("power_on"), Some(&true));

    let (lines, _) = run_command("use door", &verbs, &objects, 0, &mut inv, &mut taken, &mut won, &mut flags, &mut talk);
    assert_eq!(lines[0], "The door slides open.");
    assert!(won);
}

#[test]
fn manifest_verbs_extend_the_table() {
    let extra = vec![mrpgi_core::parser::VerbDef { name: "take".into(), words: vec!["yoink".into()] }];
    let verbs = build_verbs(&extra);
    let objects = vec![obj("battery", true, "", "", false)];
    let (mut inv, mut taken, mut won, mut flags, mut talk) = (Vec::new(), Vec::new(), false, HashMap::new(), None);
    let (lines, understood) = run_command("yoink battery", &verbs, &objects, 0, &mut inv, &mut taken, &mut won, &mut flags, &mut talk);
    assert!(understood);
    assert_eq!(lines[0], "You take the battery.");
}

/// Play the shipped sample game start → win, entirely over the bus, twice —
/// and require the two transcripts to be byte-identical (replay determinism).
#[test]
fn sample_game_win_path_is_deterministic() {
    let dir = std::env::temp_dir().join(format!("mrpgi-test-{}", std::process::id()));
    std::fs::create_dir_all(&dir).unwrap();
    mrpgi_core::kit::write_sample_world(&dir);

    let play = || -> (Vec<String>, bool) {
        let mut gs = GameState::new(World::load_game(&dir), AiConfig::off());
        let script = [
            Command::NewGame { room: None },
            Command::Parse { text: "take battery".into() },
            Command::WalkTo { x: 156, y: 85 },   // through the east door of room 0
            Command::Tick { n: 10 },
            Command::WalkTo { x: 80, y: 18 },    // through the north door of room 1
            Command::Tick { n: 10 },
            Command::Parse { text: "use hatch".into() },
            Command::Query,
        ];
        let mut won = false;
        for cmd in script {
            for e in gs.apply(cmd) {
                if matches!(e, Event::Won) {
                    won = true;
                }
            }
        }
        (gs.transcript.clone(), won)
    };

    let (t1, won1) = play();
    let (t2, won2) = play();
    assert!(won1, "expected to win the sample game; transcript: {:?}", t1);
    assert!(won2);
    assert_eq!(t1, t2, "replay must be bit-identical");

    std::fs::remove_dir_all(&dir).ok();
}

/// Headless render smoke test: the frame is a real PNG with the right size.
#[test]
fn renders_a_png_with_no_window() {
    let dir = std::env::temp_dir().join(format!("mrpgi-render-{}", std::process::id()));
    std::fs::create_dir_all(&dir).unwrap();
    mrpgi_core::kit::write_sample_world(&dir);

    let mut gs = GameState::new(World::load_game(&dir), AiConfig::off());
    gs.apply(Command::NewGame { room: None });
    let png = gs.render_png(true);
    assert_eq!(&png[..8], &[0x89, b'P', b'N', b'G', 0x0D, 0x0A, 0x1A, 0x0A]);
    let img = image::load_from_memory(&png).unwrap();
    assert_eq!((img.width(), img.height()), (160, 168));

    std::fs::remove_dir_all(&dir).ok();
}

/// Lore ingestion: upsert a new room over the bus, walk into it.
#[test]
fn upsert_room_extends_a_running_game() {
    let dir = std::env::temp_dir().join(format!("mrpgi-lore-{}", std::process::id()));
    std::fs::create_dir_all(&dir).unwrap();
    mrpgi_core::kit::write_sample_world(&dir);

    let mut gs = GameState::new(World::load_game(&dir), AiConfig::off());
    gs.apply(Command::NewGame { room: None });

    // A bad room (exit into the void) must be rejected...
    let mut bad = mrpgi_core::RoomDoc::default();
    bad.exits[0] = Some(99);
    let ev = gs.apply(Command::UpsertRoom { n: 7, doc: bad, persist: false });
    assert!(matches!(ev[0], Event::Error { .. }));

    // ...and a good one accepted and playable.
    let mut doc = mrpgi_core::RoomDoc::default();
    doc.objects.push(obj("gift", true, "", "", false));
    let ev = gs.apply(Command::UpsertRoom { n: 7, doc, persist: false });
    assert!(matches!(ev[0], Event::RoomUpserted { room: 7, .. }), "unexpected: {}", serde_json::to_string(&ev).unwrap());

    gs.apply(Command::GotoRoom { n: 7 });
    let ev = gs.apply(Command::Parse { text: "take gift".into() });
    assert!(ev.iter().any(|e| matches!(e, Event::InventoryChanged { .. })));

    std::fs::remove_dir_all(&dir).ok();
}