use shared_kernel::{normalize_optional_string, normalize_required_string, normalize_string_list};

use crate::commands::{default_tags_for_theme, validate_result_publish_fields};
use crate::{
    MATCH3D_BLOCK_VISUAL_KEYS, MATCH3D_BOARD_CENTER, MATCH3D_BOARD_RADIUS,
    MATCH3D_BOARD_SAFE_MARGIN, MATCH3D_DEFAULT_DURATION_LIMIT_MS, MATCH3D_ITEMS_PER_CLEAR,
    MATCH3D_MAX_DIFFICULTY, MATCH3D_MAX_ITEM_TYPE_COUNT, MATCH3D_MIN_DIFFICULTY,
    MATCH3D_TRAY_SLOT_COUNT, Match3DClickConfirmation, Match3DClickInput,
    Match3DClickRejectReason, Match3DCreatorConfig, Match3DFailureReason, Match3DFieldError,
    Match3DItemSnapshot, Match3DItemState, Match3DPublicationStatus, Match3DResultDraft,
    Match3DRunSnapshot, Match3DRunStatus, Match3DTraySlot, Match3DWorkProfile,
};

#[derive(Clone, Copy)]
struct Match3DSizeTierRule {
    ratio: f32,
    radius_scale: f32,
    relative_volume: f32,
    tier: &'static str,
}

const MATCH3D_SIZE_TIER_RULES: [Match3DSizeTierRule; 5] = [
    Match3DSizeTierRule {
        tier: "XL",
        ratio: 0.20,
        relative_volume: 1.86,
        radius_scale: 1.23,
    },
    Match3DSizeTierRule {
        tier: "L",
        ratio: 0.30,
        relative_volume: 1.40,
        radius_scale: 1.12,
    },
    Match3DSizeTierRule {
        tier: "M",
        ratio: 0.30,
        relative_volume: 1.00,
        radius_scale: 1.00,
    },
    Match3DSizeTierRule {
        tier: "XS",
        ratio: 0.15,
        relative_volume: 0.73,
        radius_scale: 0.90,
    },
    Match3DSizeTierRule {
        tier: "S",
        ratio: 0.05,
        relative_volume: 0.44,
        radius_scale: 0.76,
    },
];

pub fn compile_result_draft(config: &Match3DCreatorConfig) -> Match3DResultDraft {
    let game_name = format!("{}抓大鹅", config.theme_text);
    let summary = format!(
        "{}主题，{} 次消除目标，难度 {}。",
        config.theme_text, config.clear_count, config.difficulty
    );
    let tags = default_tags_for_theme(&config.theme_text);
    let mut draft = Match3DResultDraft {
        game_name,
        theme_text: config.theme_text.clone(),
        summary,
        tags,
        cover_image_src: None,
        reference_image_src: config.reference_image_src.clone(),
        clear_count: config.clear_count,
        difficulty: config.difficulty,
        publish_ready: false,
        blockers: Vec::new(),
    };
    draft.blockers = validate_result_publish_fields(&draft);
    draft.publish_ready = draft.blockers.is_empty();

    draft
}

/// 校验发布所需基础字段；试玩通关不是首版发布门槛。

pub fn create_work_profile(
    work_id: String,
    profile_id: String,
    owner_user_id: String,
    source_session_id: Option<String>,
    draft: &Match3DResultDraft,
    updated_at_micros: i64,
) -> Result<Match3DWorkProfile, Match3DFieldError> {
    let work_id = normalize_required_string(work_id).ok_or(Match3DFieldError::MissingText)?;
    let profile_id =
        normalize_required_string(profile_id).ok_or(Match3DFieldError::MissingProfileId)?;
    let owner_user_id =
        normalize_required_string(owner_user_id).ok_or(Match3DFieldError::MissingOwnerUserId)?;

    Ok(Match3DWorkProfile {
        work_id,
        profile_id,
        owner_user_id,
        source_session_id: normalize_optional_string(source_session_id),
        game_name: draft.game_name.clone(),
        theme_text: draft.theme_text.clone(),
        summary: draft.summary.clone(),
        tags: normalize_string_list(draft.tags.clone()),
        cover_image_src: draft.cover_image_src.clone(),
        reference_image_src: draft.reference_image_src.clone(),
        clear_count: draft.clear_count,
        difficulty: draft.difficulty,
        publication_status: Match3DPublicationStatus::Draft,
        play_count: 0,
        updated_at_micros,
        published_at_micros: None,
    })
}

/// 发布作品时只改变发布状态和时间戳，不在领域层写数据库。
pub fn publish_work_profile(
    profile: &Match3DWorkProfile,
    published_at_micros: i64,
) -> Result<Match3DWorkProfile, Match3DFieldError> {
    if profile.clear_count == 0 {
        return Err(Match3DFieldError::InvalidClearCount);
    }
    if !(MATCH3D_MIN_DIFFICULTY..=MATCH3D_MAX_DIFFICULTY).contains(&profile.difficulty) {
        return Err(Match3DFieldError::InvalidDifficulty);
    }

    let mut next = profile.clone();
    next.publication_status = Match3DPublicationStatus::Published;
    next.updated_at_micros = published_at_micros;
    next.published_at_micros = Some(published_at_micros);
    Ok(next)
}

/// 用确定性 seed 生成单局初始快照，便于后端权威复现和测试。
pub fn start_run_with_seed_at(
    run_id: String,
    owner_user_id: String,
    profile_id: String,
    config: &Match3DCreatorConfig,
    seed: u64,
    started_at_ms: u64,
) -> Result<Match3DRunSnapshot, Match3DFieldError> {
    let run_id = normalize_required_string(run_id).ok_or(Match3DFieldError::MissingRunId)?;
    let owner_user_id =
        normalize_required_string(owner_user_id).ok_or(Match3DFieldError::MissingOwnerUserId)?;
    let profile_id =
        normalize_required_string(profile_id).ok_or(Match3DFieldError::MissingProfileId)?;

    let total_item_count = config
        .clear_count
        .checked_mul(MATCH3D_ITEMS_PER_CLEAR)
        .ok_or(Match3DFieldError::InvalidClearCount)?;
    let mut run = Match3DRunSnapshot {
        run_id,
        profile_id,
        owner_user_id,
        status: Match3DRunStatus::Running,
        started_at_ms,
        duration_limit_ms: MATCH3D_DEFAULT_DURATION_LIMIT_MS,
        remaining_ms: MATCH3D_DEFAULT_DURATION_LIMIT_MS,
        clear_count: config.clear_count,
        total_item_count,
        cleared_item_count: 0,
        board_version: 1,
        items: build_initial_items(
            config.clear_count,
            config.difficulty,
            seed,
            &config.theme_text,
        ),
        tray_slots: empty_tray_slots(),
        failure_reason: None,
        last_confirmed_action_id: None,
    };
    refresh_clickable_flags(&mut run);
    Ok(run)
}

/// 后端权威确认一次点击：校验版本、可点击性、入槽、三消和胜负。
pub fn confirm_click_at(
    run: &Match3DRunSnapshot,
    input: &Match3DClickInput,
) -> Result<Match3DClickConfirmation, Match3DFieldError> {
    let item_instance_id = normalize_required_string(&input.item_instance_id)
        .ok_or(Match3DFieldError::MissingItemId)?;
    let client_action_id = normalize_required_string(&input.client_action_id)
        .unwrap_or_else(|| "match3d-action-unknown".to_string());

    let mut next = resolve_run_timer_at(run, input.clicked_at_ms);
    if next.status != Match3DRunStatus::Running {
        return Ok(rejected(next, Match3DClickRejectReason::RunNotActive));
    }
    if input.snapshot_version != next.board_version {
        return Ok(rejected(
            next,
            Match3DClickRejectReason::SnapshotVersionMismatch,
        ));
    }

    let Some(item_index) = next
        .items
        .iter()
        .position(|item| item.item_instance_id == item_instance_id)
    else {
        return Ok(rejected(next, Match3DClickRejectReason::ItemNotFound));
    };

    if next.items[item_index].state != Match3DItemState::InBoard {
        return Ok(rejected(next, Match3DClickRejectReason::ItemNotInBoard));
    }
    if !next.items[item_index].clickable {
        return Ok(rejected(next, Match3DClickRejectReason::ItemNotClickable));
    }

    let Some(slot_index) = first_empty_slot_index(&next.tray_slots) else {
        next = fail_run(next, Match3DFailureReason::TrayFull, client_action_id);
        return Ok(rejected(next, Match3DClickRejectReason::TrayFull));
    };

    let item_type_id = next.items[item_index].item_type_id.clone();
    next.items[item_index].state = Match3DItemState::InTray;
    next.items[item_index].clickable = false;
    next.items[item_index].tray_slot_index = Some(slot_index);
    fill_tray_slot(&mut next.tray_slots, slot_index, &next.items[item_index]);

    let cleared_item_instance_ids = clear_first_triple(&mut next, &item_type_id);
    compact_tray(&mut next);
    next.cleared_item_count = next
        .items
        .iter()
        .filter(|item| item.state == Match3DItemState::Cleared)
        .count() as u32;

    if next.cleared_item_count >= next.total_item_count {
        next.status = Match3DRunStatus::Won;
    } else if first_empty_slot_index(&next.tray_slots).is_none() {
        next.status = Match3DRunStatus::Failed;
        next.failure_reason = Some(Match3DFailureReason::TrayFull);
    }

    refresh_clickable_flags(&mut next);
    next.board_version += 1;
    next.last_confirmed_action_id = Some(client_action_id);

    Ok(Match3DClickConfirmation {
        accepted: true,
        reject_reason: None,
        entered_slot_index: Some(slot_index),
        cleared_item_instance_ids,
        run: next,
    })
}

/// 根据权威时间刷新剩余时间；前端本地倒计时归零后仍需走后端确认。
pub fn resolve_run_timer_at(run: &Match3DRunSnapshot, now_ms: u64) -> Match3DRunSnapshot {
    let mut next = run.clone();
    if next.status != Match3DRunStatus::Running {
        return next;
    }
    let elapsed_ms = now_ms.saturating_sub(next.started_at_ms);
    next.remaining_ms = next.duration_limit_ms.saturating_sub(elapsed_ms);
    if next.remaining_ms == 0 {
        next.status = Match3DRunStatus::Failed;
        next.failure_reason = Some(Match3DFailureReason::TimeUp);
        next.board_version += 1;
    }
    next
}

/// 停止当前运行态，用于试玩或玩家主动退出。
pub fn stop_run_at(run: &Match3DRunSnapshot, stopped_action_id: String) -> Match3DRunSnapshot {
    let mut next = run.clone();
    if next.status == Match3DRunStatus::Running {
        next.status = Match3DRunStatus::Stopped;
        next.board_version += 1;
        next.last_confirmed_action_id = normalize_required_string(stopped_action_id);
    }
    next
}

/// 以 2D 圆形近似判断遮挡：完全被更高层物品覆盖的物品不可点击。
pub fn refresh_clickable_flags(run: &mut Match3DRunSnapshot) {
    let board_items = run
        .items
        .iter()
        .filter(|item| item.state == Match3DItemState::InBoard)
        .cloned()
        .collect::<Vec<_>>();

    for item in &mut run.items {
        if item.state != Match3DItemState::InBoard {
            item.clickable = false;
            continue;
        }

        item.clickable = !board_items.iter().any(|cover| {
            cover.layer > item.layer
                && fully_covers(cover.x, cover.y, cover.radius, item.x, item.y, item.radius)
        });
    }
}

fn build_initial_items(
    clear_count: u32,
    difficulty: u32,
    seed: u64,
    theme_text: &str,
) -> Vec<Match3DItemSnapshot> {
    let mut rng = DeterministicRng::new(seed ^ ((clear_count as u64) << 32) ^ difficulty as u64);
    let base_radius = resolve_item_radius(difficulty);
    let selected_visual_keys = select_visual_keys(&mut rng, theme_text, clear_count);
    let item_type_count = resolve_item_type_count(clear_count);
    let size_tier_plan = resolve_size_tier_plan(item_type_count);
    let mut items = Vec::with_capacity((clear_count * MATCH3D_ITEMS_PER_CLEAR) as usize);

    for clear_index in 0..clear_count {
        let visual_index = (clear_index as usize) % item_type_count;
        let item_type_id = format!("match3d-type-{:02}", visual_index + 1);
        let visual_key = selected_visual_keys[visual_index].to_string();
        let radius = resolve_item_radius_variant(base_radius, size_tier_plan[visual_index]);

        for copy_index in 0..MATCH3D_ITEMS_PER_CLEAR {
            let (x, y) = random_point_in_circle(&mut rng, max_spawn_offset(radius));
            let instance_index = clear_index * MATCH3D_ITEMS_PER_CLEAR + copy_index;
            items.push(Match3DItemSnapshot {
                item_instance_id: format!("match3d-item-{instance_index:04}"),
                item_type_id: item_type_id.clone(),
                visual_key: visual_key.clone(),
                x,
                y,
                radius,
                layer: instance_index,
                state: Match3DItemState::InBoard,
                clickable: true,
                tray_slot_index: None,
            });
        }
    }

    // 洗牌只改变层级顺序，不改变每组三个的可通关性。
    for index in (1..items.len()).rev() {
        let swap_index = (rng.next_u32() as usize) % (index + 1);
        items.swap(index, swap_index);
    }
    for (layer, item) in items.iter_mut().enumerate() {
        item.layer = layer as u32;
    }

    items
}

fn resolve_size_tier_plan(item_type_count: usize) -> Vec<Match3DSizeTierRule> {
    let mut plans = MATCH3D_SIZE_TIER_RULES
        .iter()
        .map(|rule| {
            let exact_count = item_type_count as f32 * rule.ratio;
            (exact_count.floor() as usize, exact_count.fract(), *rule)
        })
        .collect::<Vec<_>>();
    let mut assigned_count = plans
        .iter()
        .map(|(count, _, _)| *count)
        .sum::<usize>();
    let mut remainder_order = (0..plans.len()).collect::<Vec<_>>();
    remainder_order.sort_by(|left, right| {
        plans[*right]
            .1
            .partial_cmp(&plans[*left].1)
            .unwrap_or(std::cmp::Ordering::Equal)
    });
    let mut cursor = 0;
    while assigned_count < item_type_count {
        let plan_index = remainder_order[cursor % remainder_order.len()];
        plans[plan_index].0 += 1;
        assigned_count += 1;
        cursor += 1;
    }

    plans
        .into_iter()
        .flat_map(|(count, _, rule)| std::iter::repeat(rule).take(count))
        .collect()
}

fn resolve_item_type_count(clear_count: u32) -> usize {
    clear_count.clamp(1, MATCH3D_MAX_ITEM_TYPE_COUNT) as usize
}

fn select_visual_keys(
    rng: &mut DeterministicRng,
    _theme_text: &str,
    clear_count: u32,
) -> Vec<&'static str> {
    let item_type_count = resolve_item_type_count(clear_count);
    let mut visual_keys = MATCH3D_BLOCK_VISUAL_KEYS.to_vec();
    // 中文注释：只打乱类型池顺序，不改变每个类型三件一组的可通关结构。
    for index in (1..visual_keys.len()).rev() {
        let swap_index = (rng.next_u32() as usize) % (index + 1);
        visual_keys.swap(index, swap_index);
    }
    visual_keys.truncate(item_type_count);
    visual_keys
}

fn resolve_item_radius(difficulty: u32) -> f32 {
    let clamped = difficulty.clamp(MATCH3D_MIN_DIFFICULTY, MATCH3D_MAX_DIFFICULTY);
    let radius = 0.105 - (clamped as f32 - 1.0) * 0.0055;
    radius.max(0.052)
}

fn resolve_item_radius_variant(base_radius: f32, size_tier: Match3DSizeTierRule) -> f32 {
    debug_assert!(!size_tier.tier.is_empty());
    debug_assert!(size_tier.relative_volume > 0.0);
    (base_radius * size_tier.radius_scale).clamp(0.045, 0.13)
}

fn max_spawn_offset(radius: f32) -> f32 {
    (MATCH3D_BOARD_RADIUS - MATCH3D_BOARD_SAFE_MARGIN - radius).max(0.0)
}

fn random_point_in_circle(rng: &mut DeterministicRng, max_radius: f32) -> (f32, f32) {
    for _ in 0..24 {
        let x = rng.next_unit_signed() * max_radius;
        let y = rng.next_unit_signed() * max_radius;
        if x * x + y * y <= max_radius * max_radius {
            return (MATCH3D_BOARD_CENTER + x, MATCH3D_BOARD_CENTER + y);
        }
    }
    (MATCH3D_BOARD_CENTER, MATCH3D_BOARD_CENTER)
}

fn fully_covers(
    cover_x: f32,
    cover_y: f32,
    cover_radius: f32,
    item_x: f32,
    item_y: f32,
    item_radius: f32,
) -> bool {
    let dx = cover_x - item_x;
    let dy = cover_y - item_y;
    let distance = (dx * dx + dy * dy).sqrt();
    distance + item_radius <= cover_radius * 0.96
}

fn empty_tray_slots() -> Vec<Match3DTraySlot> {
    (0..MATCH3D_TRAY_SLOT_COUNT)
        .map(|slot_index| Match3DTraySlot {
            slot_index,
            item_instance_id: None,
            item_type_id: None,
            visual_key: None,
        })
        .collect()
}

fn first_empty_slot_index(slots: &[Match3DTraySlot]) -> Option<u32> {
    slots
        .iter()
        .find(|slot| slot.item_instance_id.is_none())
        .map(|slot| slot.slot_index)
}

fn fill_tray_slot(slots: &mut [Match3DTraySlot], slot_index: u32, item: &Match3DItemSnapshot) {
    if let Some(slot) = slots.iter_mut().find(|slot| slot.slot_index == slot_index) {
        slot.item_instance_id = Some(item.item_instance_id.clone());
        slot.item_type_id = Some(item.item_type_id.clone());
        slot.visual_key = Some(item.visual_key.clone());
    }
}

fn clear_first_triple(run: &mut Match3DRunSnapshot, item_type_id: &str) -> Vec<String> {
    let matched_slot_item_ids = run
        .tray_slots
        .iter()
        .filter(|slot| slot.item_type_id.as_deref() == Some(item_type_id))
        .filter_map(|slot| slot.item_instance_id.clone())
        .take(MATCH3D_ITEMS_PER_CLEAR as usize)
        .collect::<Vec<_>>();

    if matched_slot_item_ids.len() < MATCH3D_ITEMS_PER_CLEAR as usize {
        return Vec::new();
    }

    for item in &mut run.items {
        if matched_slot_item_ids.contains(&item.item_instance_id) {
            item.state = Match3DItemState::Cleared;
            item.clickable = false;
            item.tray_slot_index = None;
        }
    }
    for slot in &mut run.tray_slots {
        if slot
            .item_instance_id
            .as_ref()
            .is_some_and(|id| matched_slot_item_ids.contains(id))
        {
            slot.item_instance_id = None;
            slot.item_type_id = None;
            slot.visual_key = None;
        }
    }

    matched_slot_item_ids
}

fn compact_tray(run: &mut Match3DRunSnapshot) {
    let mut occupied = run
        .tray_slots
        .iter()
        .filter_map(|slot| {
            Some((
                slot.item_instance_id.clone()?,
                slot.item_type_id.clone()?,
                slot.visual_key.clone()?,
            ))
        })
        .collect::<Vec<_>>();

    for slot in &mut run.tray_slots {
        slot.item_instance_id = None;
        slot.item_type_id = None;
        slot.visual_key = None;
    }

    for (slot_index, (item_instance_id, item_type_id, visual_key)) in occupied.drain(..).enumerate()
    {
        let slot_index = slot_index as u32;
        if let Some(slot) = run
            .tray_slots
            .iter_mut()
            .find(|slot| slot.slot_index == slot_index)
        {
            slot.item_instance_id = Some(item_instance_id.clone());
            slot.item_type_id = Some(item_type_id);
            slot.visual_key = Some(visual_key);
        }
        if let Some(item) = run
            .items
            .iter_mut()
            .find(|item| item.item_instance_id == item_instance_id)
        {
            item.tray_slot_index = Some(slot_index);
        }
    }
}

fn fail_run(
    mut run: Match3DRunSnapshot,
    reason: Match3DFailureReason,
    action_id: String,
) -> Match3DRunSnapshot {
    run.status = Match3DRunStatus::Failed;
    run.failure_reason = Some(reason);
    run.board_version += 1;
    run.last_confirmed_action_id = Some(action_id);
    run
}

fn rejected(
    run: Match3DRunSnapshot,
    reject_reason: Match3DClickRejectReason,
) -> Match3DClickConfirmation {
    Match3DClickConfirmation {
        accepted: false,
        reject_reason: Some(reject_reason),
        entered_slot_index: None,
        cleared_item_instance_ids: Vec::new(),
        run,
    }
}

struct DeterministicRng {
    state: u64,
}

impl DeterministicRng {
    fn new(seed: u64) -> Self {
        Self { state: seed.max(1) }
    }

    fn next_u32(&mut self) -> u32 {
        let mut value = self.state;
        value ^= value << 13;
        value ^= value >> 7;
        value ^= value << 17;
        self.state = value;
        (value >> 32) as u32
    }

    fn next_unit_signed(&mut self) -> f32 {
        let value = self.next_u32() as f32 / u32::MAX as f32;
        value * 2.0 - 1.0
    }
}

#[cfg(test)]
mod tests {
    use std::collections::BTreeMap;

    use super::*;
    use crate::commands::{build_creator_config, validate_publish_requirements};

    fn test_config(clear_count: u32) -> Match3DCreatorConfig {
        build_creator_config("水果", None, clear_count, 4).expect("config should be valid")
    }

    fn manual_item(id: &str, type_id: &str, slot: Option<u32>) -> Match3DItemSnapshot {
        Match3DItemSnapshot {
            item_instance_id: id.to_string(),
            item_type_id: type_id.to_string(),
            visual_key: type_id.to_string(),
            x: 0.0,
            y: 0.0,
            radius: 0.08,
            layer: 0,
            state: if slot.is_some() {
                Match3DItemState::InTray
            } else {
                Match3DItemState::InBoard
            },
            clickable: slot.is_none(),
            tray_slot_index: slot,
        }
    }

    #[test]
    fn creator_config_requires_positive_clear_count() {
        let error = build_creator_config("水果", None, 0, 3).expect_err("zero should fail");
        assert_eq!(error, Match3DFieldError::InvalidClearCount);
    }

    #[test]
    fn draft_requires_cover_before_publish() {
        let mut draft = compile_result_draft(&test_config(2));

        assert!(!draft.publish_ready);
        assert!(draft.blockers.contains(&"封面图不能为空".to_string()));

        draft.cover_image_src = Some("https://example.com/cover.png".to_string());
        assert!(validate_publish_requirements(&draft).is_empty());
    }

    #[test]
    fn initial_run_generates_triples() {
        let run = start_run_with_seed_at(
            "run-1".to_string(),
            "user-1".to_string(),
            "profile-1".to_string(),
            &test_config(12),
            42,
            1_000,
        )
        .expect("run should start");

        assert_eq!(run.total_item_count, 36);
        let mut counts = BTreeMap::<String, u32>::new();
        for item in &run.items {
            *counts.entry(item.item_type_id.clone()).or_default() += 1;
        }
        assert!(counts.values().all(|count| count % 3 == 0));
    }

    #[test]
    fn item_type_count_follows_clear_count_until_twenty_five() {
        let run = start_run_with_seed_at(
            "run-types-small".to_string(),
            "user-1".to_string(),
            "profile-1".to_string(),
            &test_config(12),
            42,
            1_000,
        )
        .expect("run should start");

        let mut counts = BTreeMap::<String, u32>::new();
        for item in &run.items {
            *counts.entry(item.item_type_id.clone()).or_default() += 1;
        }

        assert_eq!(counts.len(), 12);
        assert!(counts.values().all(|count| *count == 3));
    }

    #[test]
    fn visual_key_count_follows_fifteen_clear_count() {
        let run = start_run_with_seed_at(
            "run-types-fifteen".to_string(),
            "user-1".to_string(),
            "profile-1".to_string(),
            &test_config(15),
            42,
            1_000,
        )
        .expect("run should start");

        let mut counts = BTreeMap::<String, u32>::new();
        let mut item_types_by_visual_key = BTreeMap::<String, Vec<String>>::new();
        for item in &run.items {
            *counts.entry(item.visual_key.clone()).or_default() += 1;
            item_types_by_visual_key
                .entry(item.visual_key.clone())
                .or_default()
                .push(item.item_type_id.clone());
        }

        assert_eq!(counts.len(), 15);
        assert!(counts.values().all(|count| *count == 3));
        assert!(item_types_by_visual_key.values().all(|item_type_ids| {
            item_type_ids
                .iter()
                .all(|item_type_id| item_type_id == &item_type_ids[0])
        }));
    }

    #[test]
    fn item_type_count_is_capped_at_twenty_five() {
        let run = start_run_with_seed_at(
            "run-types-large".to_string(),
            "user-1".to_string(),
            "profile-1".to_string(),
            &test_config(100),
            42,
            1_000,
        )
        .expect("run should start");

        let mut counts = BTreeMap::<String, u32>::new();
        for item in &run.items {
            *counts.entry(item.item_type_id.clone()).or_default() += 1;
        }

        assert_eq!(counts.len(), 25);
        assert!(counts.values().all(|count| count % 3 == 0));
    }

    #[test]
    fn initial_run_uses_slightly_different_item_sizes() {
        let run = start_run_with_seed_at(
            "run-size".to_string(),
            "user-1".to_string(),
            "profile-1".to_string(),
            &test_config(6),
            21,
            1_000,
        )
        .expect("run should start");

        let mut radii = run
            .items
            .iter()
            .map(|item| (item.radius * 1_000.0).round() as u32)
            .collect::<Vec<_>>();
        radii.sort();
        radii.dedup();

        assert!(radii.len() > 1);
    }

    #[test]
    fn size_tier_plan_follows_ratio_for_twenty_five_types() {
        let plan = resolve_size_tier_plan(25);
        let mut counts = BTreeMap::<&str, usize>::new();
        for rule in plan {
            *counts.entry(rule.tier).or_default() += 1;
            match rule.tier {
                "XL" => assert!((1.60..=2.30).contains(&rule.relative_volume)),
                "L" => assert!((1.25..=1.60).contains(&rule.relative_volume)),
                "M" => assert_eq!(rule.relative_volume, 1.00),
                "XS" => assert!((0.65..=0.85).contains(&rule.relative_volume)),
                "S" => assert!((0.35..=0.50).contains(&rule.relative_volume)),
                _ => panic!("unknown size tier"),
            }
        }

        assert_eq!(counts.get("XL"), Some(&5));
        assert_eq!(counts.get("L"), Some(&8));
        assert_eq!(counts.get("M"), Some(&7));
        assert_eq!(counts.get("XS"), Some(&4));
        assert_eq!(counts.get("S"), Some(&1));
    }

    #[test]
    fn same_visual_key_keeps_one_size_in_run() {
        let run = start_run_with_seed_at(
            "run-size-unique".to_string(),
            "user-1".to_string(),
            "profile-1".to_string(),
            &test_config(30),
            42,
            1_000,
        )
        .expect("run should start");

        let mut radii_by_visual_key = BTreeMap::<String, Vec<u32>>::new();
        for item in &run.items {
            radii_by_visual_key
                .entry(item.visual_key.clone())
                .or_default()
                .push((item.radius * 10_000.0).round() as u32);
        }

        assert_eq!(radii_by_visual_key.len(), 25);
        assert!(radii_by_visual_key.values().all(|radii| {
            radii.iter().all(|radius| radius == &radii[0])
        }));
    }

    #[test]
    fn block_visuals_stay_inside_board() {
        let run = start_run_with_seed_at(
            "run-blocks".to_string(),
            "user-1".to_string(),
            "profile-1".to_string(),
            &test_config(10),
            12,
            1_000,
        )
        .expect("run should start");

        let visual_keys = run
            .items
            .iter()
            .map(|item| item.visual_key.as_str())
            .collect::<Vec<_>>();
        assert!(visual_keys.iter().all(|visual_key| visual_key.starts_with("block-")));

        for item in &run.items {
            let dx = item.x - MATCH3D_BOARD_CENTER;
            let dy = item.y - MATCH3D_BOARD_CENTER;
            let distance = (dx * dx + dy * dy).sqrt();
            assert!(
                distance + item.radius <= MATCH3D_BOARD_RADIUS - MATCH3D_BOARD_SAFE_MARGIN + 0.0001,
                "item {} should stay inside board: x={}, y={}, radius={}",
                item.item_instance_id,
                item.x,
                item.y,
                item.radius
            );
        }
    }

    #[test]
    fn twenty_five_or_less_does_not_repeat_visual_keys() {
        let run = start_run_with_seed_at(
            "run-block-unique".to_string(),
            "user-1".to_string(),
            "profile-1".to_string(),
            &test_config(25),
            27,
            1_000,
        )
        .expect("run should start");

        let mut counts = BTreeMap::<String, u32>::new();
        for item in &run.items {
            *counts.entry(item.visual_key.clone()).or_default() += 1;
        }

        assert_eq!(counts.len(), 25);
        assert!(counts.values().all(|count| *count == 3));
    }

    #[test]
    fn block_visuals_have_different_relative_sizes() {
        let config = build_creator_config("玩具", None, 3, 4).expect("config should be valid");
        let run = start_run_with_seed_at(
            "run-block-size".to_string(),
            "user-1".to_string(),
            "profile-1".to_string(),
            &config,
            13,
            1_000,
        )
        .expect("run should start");

        let mut radii = run
            .items
            .iter()
            .map(|item| (item.radius * 1_000.0).round() as u32)
            .collect::<Vec<_>>();
        radii.sort();
        radii.dedup();

        assert!(radii.len() > 1);
    }

    #[test]
    fn clicking_three_same_items_clears_and_wins() {
        let mut run = start_run_with_seed_at(
            "run-1".to_string(),
            "user-1".to_string(),
            "profile-1".to_string(),
            &test_config(1),
            7,
            10_000,
        )
        .expect("run should start");
        for item in &mut run.items {
            item.clickable = true;
        }

        let ids = run
            .items
            .iter()
            .map(|item| item.item_instance_id.clone())
            .collect::<Vec<_>>();

        for (index, item_id) in ids.iter().enumerate() {
            let input = Match3DClickInput {
                run_id: run.run_id.clone(),
                owner_user_id: run.owner_user_id.clone(),
                item_instance_id: item_id.clone(),
                client_action_id: format!("action-{index}"),
                snapshot_version: run.board_version,
                clicked_at_ms: 11_000 + index as u64,
            };
            run = confirm_click_at(&run, &input)
                .expect("click should confirm")
                .run;
        }

        assert_eq!(run.status, Match3DRunStatus::Won);
        assert_eq!(run.cleared_item_count, 3);
        assert!(
            run.tray_slots
                .iter()
                .all(|slot| slot.item_instance_id.is_none())
        );
    }

    #[test]
    fn tray_full_fails_when_no_triple_can_clear() {
        let mut run = Match3DRunSnapshot {
            run_id: "run-full".to_string(),
            profile_id: "profile-1".to_string(),
            owner_user_id: "user-1".to_string(),
            status: Match3DRunStatus::Running,
            started_at_ms: 0,
            duration_limit_ms: MATCH3D_DEFAULT_DURATION_LIMIT_MS,
            remaining_ms: MATCH3D_DEFAULT_DURATION_LIMIT_MS,
            clear_count: 3,
            total_item_count: 9,
            cleared_item_count: 0,
            board_version: 1,
            items: (0..8)
                .map(|index| manual_item(&format!("item-{index}"), &format!("type-{index}"), None))
                .collect(),
            tray_slots: empty_tray_slots(),
            failure_reason: None,
            last_confirmed_action_id: None,
        };

        for index in 0..7 {
            let input = Match3DClickInput {
                run_id: run.run_id.clone(),
                owner_user_id: run.owner_user_id.clone(),
                item_instance_id: format!("item-{index}"),
                client_action_id: format!("action-{index}"),
                snapshot_version: run.board_version,
                clicked_at_ms: 1_000 + index,
            };
            run = confirm_click_at(&run, &input)
                .expect("click should confirm")
                .run;
        }

        assert_eq!(run.status, Match3DRunStatus::Failed);
        assert_eq!(run.failure_reason, Some(Match3DFailureReason::TrayFull));
    }

    #[test]
    fn timer_expiration_fails_running_run() {
        let run = start_run_with_seed_at(
            "run-1".to_string(),
            "user-1".to_string(),
            "profile-1".to_string(),
            &test_config(2),
            9,
            1_000,
        )
        .expect("run should start");

        let expired = resolve_run_timer_at(&run, 1_000 + MATCH3D_DEFAULT_DURATION_LIMIT_MS);

        assert_eq!(expired.status, Match3DRunStatus::Failed);
        assert_eq!(expired.failure_reason, Some(Match3DFailureReason::TimeUp));
    }

    #[test]
    fn fully_covered_item_is_not_clickable() {
        let mut run = Match3DRunSnapshot {
            run_id: "run-cover".to_string(),
            profile_id: "profile-1".to_string(),
            owner_user_id: "user-1".to_string(),
            status: Match3DRunStatus::Running,
            started_at_ms: 0,
            duration_limit_ms: MATCH3D_DEFAULT_DURATION_LIMIT_MS,
            remaining_ms: MATCH3D_DEFAULT_DURATION_LIMIT_MS,
            clear_count: 1,
            total_item_count: 2,
            cleared_item_count: 0,
            board_version: 1,
            items: vec![
                Match3DItemSnapshot {
                    layer: 0,
                    radius: 0.04,
                    ..manual_item("bottom", "type-a", None)
                },
                Match3DItemSnapshot {
                    layer: 1,
                    radius: 0.08,
                    ..manual_item("top", "type-b", None)
                },
            ],
            tray_slots: empty_tray_slots(),
            failure_reason: None,
            last_confirmed_action_id: None,
        };

        refresh_clickable_flags(&mut run);

        let bottom = run
            .items
            .iter()
            .find(|item| item.item_instance_id == "bottom")
            .expect("bottom item should exist");
        assert!(!bottom.clickable);
    }
}