use crate::*;

const ASSET_HISTORY_MAX_LIMIT: usize = 120;
const ASSET_HISTORY_CHARACTER_VISUAL_KIND: &str = "character_visual";
const ASSET_HISTORY_SCENE_IMAGE_KIND: &str = "scene_image";
const ASSET_HISTORY_PUZZLE_COVER_IMAGE_KIND: &str = "puzzle_cover_image";

#[spacetimedb::table(
    accessor = asset_object,
    index(accessor = by_bucket_object_key, btree(columns = [bucket, object_key]))
)]
pub struct AssetObject {
    #[primary_key]
    asset_object_id: String,
    // 正式对象定位固定拆成 bucket + object_key 两列，避免后续再从单字符串路径做 schema 拆分。
    bucket: String,
    object_key: String,
    access_policy: AssetObjectAccessPolicy,
    content_type: Option<String>,
    content_length: u64,
    content_hash: Option<String>,
    version: u32,
    source_job_id: Option<String>,
    owner_user_id: Option<String>,
    profile_id: Option<String>,
    entity_id: Option<String>,
    #[index(btree)]
    asset_kind: String,
    created_at: Timestamp,
    updated_at: Timestamp,
}

// reducer 负责固定资产对象的正式写规则，供后续内部模块逻辑复用。
#[spacetimedb::reducer]
pub fn confirm_asset_object(
    ctx: &ReducerContext,
    input: AssetObjectUpsertInput,
) -> Result<(), String> {
    upsert_asset_object(ctx, input).map(|_| ())
}

// procedure 面向 Axum 同步确认接口，返回最终持久化后的对象记录，避免 HTTP 层再额外查询 private table。
#[spacetimedb::procedure]
pub fn confirm_asset_object_and_return(
    ctx: &mut ProcedureContext,
    input: AssetObjectUpsertInput,
) -> AssetObjectProcedureResult {
    match ctx.try_with_tx(|tx| upsert_asset_object(tx, input.clone())) {
        Ok(record) => AssetObjectProcedureResult {
            ok: true,
            record: Some(record),
            error_message: None,
        },
        Err(message) => AssetObjectProcedureResult {
            ok: false,
            record: None,
            error_message: Some(message),
        },
    }
}

// 历史素材只返回编辑器复用所需的脱敏字段，asset_object 本表继续保持 private。
#[spacetimedb::procedure]
pub fn list_asset_history_and_return(
    ctx: &mut ProcedureContext,
    input: AssetHistoryListInput,
) -> AssetHistoryListResult {
    match ctx.try_with_tx(|tx| list_asset_history(tx, input.clone())) {
        Ok(entries) => AssetHistoryListResult {
            ok: true,
            entries,
            error_message: None,
        },
        Err(message) => AssetHistoryListResult {
            ok: false,
            entries: Vec::new(),
            error_message: Some(message),
        },
    }
}

pub(crate) fn upsert_asset_object(
    ctx: &ReducerContext,
    input: AssetObjectUpsertInput,
) -> Result<AssetObjectUpsertSnapshot, String> {
    validate_asset_object_fields(
        &input.bucket,
        &input.object_key,
        &input.asset_kind,
        input.version,
    )
    .map_err(|error| error.to_string())?;

    let updated_at = Timestamp::from_micros_since_unix_epoch(input.updated_at_micros);
    // 这里先保持最小可发布实现：查重语义已经冻结，后续再把实现优化回组合索引扫描。
    let current = ctx
        .db
        .asset_object()
        .iter()
        .find(|row| row.bucket == input.bucket && row.object_key == input.object_key);

    let snapshot = match current {
        Some(existing) => {
            ctx.db
                .asset_object()
                .asset_object_id()
                .delete(&existing.asset_object_id);
            let row = AssetObject {
                asset_object_id: existing.asset_object_id.clone(),
                bucket: input.bucket.clone(),
                object_key: input.object_key.clone(),
                access_policy: input.access_policy,
                content_type: input.content_type.clone(),
                content_length: input.content_length,
                content_hash: input.content_hash.clone(),
                version: input.version,
                source_job_id: input.source_job_id.clone(),
                owner_user_id: input.owner_user_id.clone(),
                profile_id: input.profile_id.clone(),
                entity_id: input.entity_id.clone(),
                asset_kind: input.asset_kind.clone(),
                created_at: existing.created_at,
                updated_at,
            };
            ctx.db.asset_object().insert(row);

            AssetObjectUpsertSnapshot {
                asset_object_id: existing.asset_object_id,
                bucket: input.bucket,
                object_key: input.object_key,
                access_policy: input.access_policy,
                content_type: input.content_type,
                content_length: input.content_length,
                content_hash: input.content_hash,
                version: input.version,
                source_job_id: input.source_job_id,
                owner_user_id: input.owner_user_id,
                profile_id: input.profile_id,
                entity_id: input.entity_id,
                asset_kind: input.asset_kind,
                created_at_micros: existing.created_at.to_micros_since_unix_epoch(),
                updated_at_micros: input.updated_at_micros,
            }
        }
        None => {
            let created_at = updated_at;
            let row = AssetObject {
                asset_object_id: input.asset_object_id.clone(),
                bucket: input.bucket.clone(),
                object_key: input.object_key.clone(),
                access_policy: input.access_policy,
                content_type: input.content_type.clone(),
                content_length: input.content_length,
                content_hash: input.content_hash.clone(),
                version: input.version,
                source_job_id: input.source_job_id.clone(),
                owner_user_id: input.owner_user_id.clone(),
                profile_id: input.profile_id.clone(),
                entity_id: input.entity_id.clone(),
                asset_kind: input.asset_kind.clone(),
                created_at,
                updated_at,
            };
            ctx.db.asset_object().insert(row);

            AssetObjectUpsertSnapshot {
                asset_object_id: input.asset_object_id,
                bucket: input.bucket,
                object_key: input.object_key,
                access_policy: input.access_policy,
                content_type: input.content_type,
                content_length: input.content_length,
                content_hash: input.content_hash,
                version: input.version,
                source_job_id: input.source_job_id,
                owner_user_id: input.owner_user_id,
                profile_id: input.profile_id,
                entity_id: input.entity_id,
                asset_kind: input.asset_kind,
                created_at_micros: input.updated_at_micros,
                updated_at_micros: input.updated_at_micros,
            }
        }
    };

    Ok(snapshot)
}

pub(crate) fn has_asset_object(ctx: &ReducerContext, asset_object_id: &str) -> bool {
    ctx.db
        .asset_object()
        .iter()
        .any(|row| row.asset_object_id == asset_object_id)
}

fn list_asset_history(
    ctx: &ReducerContext,
    input: AssetHistoryListInput,
) -> Result<Vec<AssetHistoryEntrySnapshot>, String> {
    let asset_kind = input.asset_kind.trim();
    if asset_kind != ASSET_HISTORY_CHARACTER_VISUAL_KIND
        && asset_kind != ASSET_HISTORY_SCENE_IMAGE_KIND
        && asset_kind != ASSET_HISTORY_PUZZLE_COVER_IMAGE_KIND
    {
        return Err(
            "历史素材类型只支持 character_visual、scene_image 或 puzzle_cover_image".to_string(),
        );
    }

    let limit = usize::try_from(input.limit)
        .unwrap_or(ASSET_HISTORY_MAX_LIMIT)
        .clamp(1, ASSET_HISTORY_MAX_LIMIT);
    let mut entries = ctx
        .db
        .asset_object()
        .iter()
        .filter(|row| row.asset_kind == asset_kind)
        .map(|row| AssetHistoryEntrySnapshot {
            asset_object_id: row.asset_object_id,
            asset_kind: row.asset_kind,
            image_src: object_key_to_legacy_image_src(row.object_key.as_str()),
            owner_user_id: row.owner_user_id,
            profile_id: row.profile_id,
            entity_id: row.entity_id,
            created_at_micros: row.created_at.to_micros_since_unix_epoch(),
            updated_at_micros: row.updated_at.to_micros_since_unix_epoch(),
        })
        .collect::<Vec<_>>();

    entries.sort_by(|left, right| {
        right
            .created_at_micros
            .cmp(&left.created_at_micros)
            .then_with(|| right.asset_object_id.cmp(&left.asset_object_id))
    });
    entries.truncate(limit);
    Ok(entries)
}

fn object_key_to_legacy_image_src(object_key: &str) -> String {
    let normalized = object_key.trim().trim_start_matches('/');
    if normalized.is_empty() {
        return String::new();
    }
    format!("/{normalized}")
}