use sea_orm::{ColumnTrait, ConnectionTrait, EntityTrait, FromQueryResult, QueryFilter, Statement};
use uuid::Uuid;

use erp_core::error::{AppError, AppResult};
use erp_core::events::EventBus;

use crate::data_dto::PluginDataResp;
use crate::dynamic_table::DynamicTableManager;
use crate::entity::plugin;
use crate::entity::plugin_entity;
use crate::error::PluginError;
use crate::manifest::PluginField;

pub struct PluginDataService;

/// 插件实体信息（合并查询减少 DB 调用）
struct EntityInfo {
    table_name: String,
    schema_json: serde_json::Value,
}

impl EntityInfo {
    fn fields(&self) -> AppResult<Vec<PluginField>> {
        let entity_def: crate::manifest::PluginEntity =
            serde_json::from_value(self.schema_json.clone())
                .map_err(|e| AppError::Internal(format!("解析 entity schema 失败: {}", e)))?;
        Ok(entity_def.fields)
    }
}

impl PluginDataService {
    /// 创建插件数据
    pub async fn create(
        plugin_id: Uuid,
        entity_name: &str,
        tenant_id: Uuid,
        operator_id: Uuid,
        data: serde_json::Value,
        db: &sea_orm::DatabaseConnection,
        _event_bus: &EventBus,
    ) -> AppResult<PluginDataResp> {
        let info = resolve_entity_info(plugin_id, entity_name, tenant_id, db).await?;
        let fields = info.fields()?;
        validate_data(&data, &fields)?;

        let (sql, values) =
            DynamicTableManager::build_insert_sql(&info.table_name, tenant_id, operator_id, &data);

        #[derive(FromQueryResult)]
        struct InsertResult {
            id: Uuid,
            data: serde_json::Value,
            created_at: chrono::DateTime<chrono::Utc>,
            updated_at: chrono::DateTime<chrono::Utc>,
            version: i32,
        }

        let result = InsertResult::find_by_statement(Statement::from_sql_and_values(
            sea_orm::DatabaseBackend::Postgres,
            sql,
            values,
        ))
        .one(db)
        .await?
        .ok_or_else(|| PluginError::DatabaseError("INSERT 未返回结果".to_string()))?;

        Ok(PluginDataResp {
            id: result.id.to_string(),
            data: result.data,
            created_at: Some(result.created_at),
            updated_at: Some(result.updated_at),
            version: Some(result.version),
        })
    }

    /// 列表查询（支持过滤/搜索/排序）
    pub async fn list(
        plugin_id: Uuid,
        entity_name: &str,
        tenant_id: Uuid,
        page: u64,
        page_size: u64,
        db: &sea_orm::DatabaseConnection,
        filter: Option<serde_json::Value>,
        search: Option<String>,
        sort_by: Option<String>,
        sort_order: Option<String>,
    ) -> AppResult<(Vec<PluginDataResp>, u64)> {
        let info = resolve_entity_info(plugin_id, entity_name, tenant_id, db).await?;

        // 获取 searchable 字段列表
        let entity_fields = info.fields()?;
        let search_tuple = {
            let searchable: Vec<&str> = entity_fields
                .iter()
                .filter(|f| f.searchable == Some(true))
                .map(|f| f.name.as_str())
                .collect();
            match (searchable.is_empty(), &search) {
                (false, Some(kw)) => Some((searchable.join(","), kw.clone())),
                _ => None,
            }
        };

        // Count
        let (count_sql, count_values) =
            DynamicTableManager::build_count_sql(&info.table_name, tenant_id);
        #[derive(FromQueryResult)]
        struct CountResult {
            count: i64,
        }
        let total = CountResult::find_by_statement(Statement::from_sql_and_values(
            sea_orm::DatabaseBackend::Postgres,
            count_sql,
            count_values,
        ))
        .one(db)
        .await?
        .map(|r| r.count as u64)
        .unwrap_or(0);

        // Query
        let offset = page.saturating_sub(1) * page_size;
        let (sql, values) = DynamicTableManager::build_filtered_query_sql(
            &info.table_name,
            tenant_id,
            page_size,
            offset,
            filter,
            search_tuple,
            sort_by,
            sort_order,
        )
        .map_err(|e| AppError::Validation(e))?;

        #[derive(FromQueryResult)]
        struct DataRow {
            id: Uuid,
            data: serde_json::Value,
            created_at: chrono::DateTime<chrono::Utc>,
            updated_at: chrono::DateTime<chrono::Utc>,
            version: i32,
        }

        let rows = DataRow::find_by_statement(Statement::from_sql_and_values(
            sea_orm::DatabaseBackend::Postgres,
            sql,
            values,
        ))
        .all(db)
        .await?;

        let items = rows
            .into_iter()
            .map(|r| PluginDataResp {
                id: r.id.to_string(),
                data: r.data,
                created_at: Some(r.created_at),
                updated_at: Some(r.updated_at),
                version: Some(r.version),
            })
            .collect();

        Ok((items, total))
    }

    /// 按 ID 获取
    pub async fn get_by_id(
        plugin_id: Uuid,
        entity_name: &str,
        id: Uuid,
        tenant_id: Uuid,
        db: &sea_orm::DatabaseConnection,
    ) -> AppResult<PluginDataResp> {
        let info = resolve_entity_info(plugin_id, entity_name, tenant_id, db).await?;
        let (sql, values) = DynamicTableManager::build_get_by_id_sql(&info.table_name, id, tenant_id);

        #[derive(FromQueryResult)]
        struct DataRow {
            id: Uuid,
            data: serde_json::Value,
            created_at: chrono::DateTime<chrono::Utc>,
            updated_at: chrono::DateTime<chrono::Utc>,
            version: i32,
        }

        let row = DataRow::find_by_statement(Statement::from_sql_and_values(
            sea_orm::DatabaseBackend::Postgres,
            sql,
            values,
        ))
        .one(db)
        .await?
        .ok_or_else(|| AppError::NotFound("记录不存在".to_string()))?;

        Ok(PluginDataResp {
            id: row.id.to_string(),
            data: row.data,
            created_at: Some(row.created_at),
            updated_at: Some(row.updated_at),
            version: Some(row.version),
        })
    }

    /// 更新
    pub async fn update(
        plugin_id: Uuid,
        entity_name: &str,
        id: Uuid,
        tenant_id: Uuid,
        operator_id: Uuid,
        data: serde_json::Value,
        expected_version: i32,
        db: &sea_orm::DatabaseConnection,
        _event_bus: &EventBus,
    ) -> AppResult<PluginDataResp> {
        let info = resolve_entity_info(plugin_id, entity_name, tenant_id, db).await?;
        let fields = info.fields()?;
        validate_data(&data, &fields)?;

        let (sql, values) = DynamicTableManager::build_update_sql(
            &info.table_name,
            id,
            tenant_id,
            operator_id,
            &data,
            expected_version,
        );

        #[derive(FromQueryResult)]
        struct UpdateResult {
            id: Uuid,
            data: serde_json::Value,
            created_at: chrono::DateTime<chrono::Utc>,
            updated_at: chrono::DateTime<chrono::Utc>,
            version: i32,
        }

        let result = UpdateResult::find_by_statement(Statement::from_sql_and_values(
            sea_orm::DatabaseBackend::Postgres,
            sql,
            values,
        ))
        .one(db)
        .await?
        .ok_or_else(|| AppError::VersionMismatch)?;

        Ok(PluginDataResp {
            id: result.id.to_string(),
            data: result.data,
            created_at: Some(result.created_at),
            updated_at: Some(result.updated_at),
            version: Some(result.version),
        })
    }

    /// 删除（软删除）
    pub async fn delete(
        plugin_id: Uuid,
        entity_name: &str,
        id: Uuid,
        tenant_id: Uuid,
        db: &sea_orm::DatabaseConnection,
        _event_bus: &EventBus,
    ) -> AppResult<()> {
        let info = resolve_entity_info(plugin_id, entity_name, tenant_id, db).await?;
        let (sql, values) = DynamicTableManager::build_delete_sql(&info.table_name, id, tenant_id);

        db.execute(Statement::from_sql_and_values(
            sea_orm::DatabaseBackend::Postgres,
            sql,
            values,
        ))
        .await?;

        Ok(())
    }

    /// 统计记录数（支持过滤和搜索）
    pub async fn count(
        plugin_id: Uuid,
        entity_name: &str,
        tenant_id: Uuid,
        db: &sea_orm::DatabaseConnection,
        filter: Option<serde_json::Value>,
        search: Option<String>,
    ) -> AppResult<u64> {
        let info = resolve_entity_info(plugin_id, entity_name, tenant_id, db).await?;

        let entity_fields = info.fields()?;
        let search_tuple = {
            let searchable: Vec<&str> = entity_fields
                .iter()
                .filter(|f| f.searchable == Some(true))
                .map(|f| f.name.as_str())
                .collect();
            match (searchable.is_empty(), &search) {
                (false, Some(kw)) => Some((searchable.join(","), kw.clone())),
                _ => None,
            }
        };

        let (sql, values) = DynamicTableManager::build_filtered_count_sql(
            &info.table_name,
            tenant_id,
            filter,
            search_tuple,
        )
        .map_err(|e| AppError::Validation(e))?;

        #[derive(FromQueryResult)]
        struct CountResult {
            count: i64,
        }

        let result = CountResult::find_by_statement(Statement::from_sql_and_values(
            sea_orm::DatabaseBackend::Postgres,
            sql,
            values,
        ))
        .one(db)
        .await?
        .map(|r| r.count as u64)
        .unwrap_or(0);

        Ok(result)
    }

    /// 聚合查询 — 按字段分组计数
    /// 返回 [(分组键, 计数), ...]
    pub async fn aggregate(
        plugin_id: Uuid,
        entity_name: &str,
        tenant_id: Uuid,
        db: &sea_orm::DatabaseConnection,
        group_by_field: &str,
        filter: Option<serde_json::Value>,
    ) -> AppResult<Vec<(String, i64)>> {
        let info = resolve_entity_info(plugin_id, entity_name, tenant_id, db).await?;

        let (sql, values) = DynamicTableManager::build_aggregate_sql(
            &info.table_name,
            tenant_id,
            group_by_field,
            filter,
        )
        .map_err(|e| AppError::Validation(e))?;

        #[derive(FromQueryResult)]
        struct AggRow {
            key: Option<String>,
            count: i64,
        }

        let rows = AggRow::find_by_statement(Statement::from_sql_and_values(
            sea_orm::DatabaseBackend::Postgres,
            sql,
            values,
        ))
        .all(db)
        .await?;

        let result = rows
            .into_iter()
            .map(|r| (r.key.unwrap_or_default(), r.count))
            .collect();

        Ok(result)
    }
}

/// 从 plugins 表解析 manifest metadata.id（如 "erp-crm"）
pub async fn resolve_manifest_id(
    plugin_id: Uuid,
    tenant_id: Uuid,
    db: &sea_orm::DatabaseConnection,
) -> AppResult<String> {
    let model = plugin::Entity::find()
        .filter(plugin::Column::Id.eq(plugin_id))
        .filter(plugin::Column::TenantId.eq(tenant_id))
        .filter(plugin::Column::DeletedAt.is_null())
        .one(db)
        .await?
        .ok_or_else(|| AppError::NotFound(format!("插件 {} 不存在", plugin_id)))?;

    let manifest: crate::manifest::PluginManifest =
        serde_json::from_value(model.manifest_json)
            .map_err(|e| AppError::Internal(format!("解析插件 manifest 失败: {}", e)))?;

    Ok(manifest.metadata.id)
}

/// 从 plugin_entities 表获取实体完整信息（带租户隔离）
async fn resolve_entity_info(
    plugin_id: Uuid,
    entity_name: &str,
    tenant_id: Uuid,
    db: &sea_orm::DatabaseConnection,
) -> AppResult<EntityInfo> {
    let entity = plugin_entity::Entity::find()
        .filter(plugin_entity::Column::PluginId.eq(plugin_id))
        .filter(plugin_entity::Column::TenantId.eq(tenant_id))
        .filter(plugin_entity::Column::EntityName.eq(entity_name))
        .filter(plugin_entity::Column::DeletedAt.is_null())
        .one(db)
        .await?
        .ok_or_else(|| {
            AppError::NotFound(format!("插件实体 {}/{} 不存在", plugin_id, entity_name))
        })?;

    Ok(EntityInfo {
        table_name: entity.table_name,
        schema_json: entity.schema_json,
    })
}

/// 校验数据：检查 required 字段
fn validate_data(data: &serde_json::Value, fields: &[PluginField]) -> AppResult<()> {
    let obj = data.as_object().ok_or_else(|| {
        AppError::Validation("data 必须是 JSON 对象".to_string())
    })?;
    for field in fields {
        if field.required && !obj.contains_key(&field.name) {
            let label = field.display_name.as_deref().unwrap_or(&field.name);
            return Err(AppError::Validation(format!("字段 '{}' 不能为空", label)));
        }
    }
    Ok(())
}