wedb_embed 0.1.0

use crate::error::{Error, Result};
use crate::search::ast::{
    explain_search_query, explain_search_query_cli, parse_search_query_with_params,
};
use crate::search::conf::{FtCreate, FtInfo, FtSearch, SearchResult, SuggestionItem};
use crate::search::index::InvertedIndex;
use crate::search::meta::SearchIndexSchema;
use crate::search::sug::SuggestionDict;
use hipstr::HipStr;
use rapidhash::RapidHashMap;

/// 索引管理器（对标 Apache Kvrocks kqir::IndexMap 与 IndexManager）
#[derive(Debug, Clone, Default)]
pub struct SearchIndexManager {
    pub indexes: RapidHashMap<HipStr<'static>, (SearchIndexSchema, InvertedIndex)>,
    pub aliases: RapidHashMap<HipStr<'static>, HipStr<'static>>,
    pub suggestions: RapidHashMap<HipStr<'static>, SuggestionDict>,
    pub configs: RapidHashMap<String, String>,
}

impl SearchIndexManager {
    pub fn new() -> Self {
        let mut configs = RapidHashMap::default();
        configs.insert("TIMEOUT".to_string(), "500".to_string());
        configs.insert("DEFAULT_DIALECT".to_string(), "2".to_string());
        configs.insert("MINPREFIX".to_string(), "2".to_string());
        configs.insert("MAXEXPANSIONS".to_string(), "200".to_string());
        Self {
            indexes: RapidHashMap::default(),
            aliases: RapidHashMap::default(),
            suggestions: RapidHashMap::default(),
            configs,
        }
    }

    /// 创建索引（FT.CREATE）
    pub fn create_index(&mut self, schema: SearchIndexSchema) -> Result<()> {
        let name = schema.name.clone();
        if self.indexes.contains_key(&name) {
            return Err(Error::invalid_data(format!(
                "Index '{name}' already exists"
            )));
        }
        self.indexes.insert(name, (schema, InvertedIndex::new()));
        Ok(())
    }

    /// 从 FT.CREATE 选项创建索引
    pub fn create_index_from_opts(&mut self, opts: FtCreate) -> Result<()> {
        self.create_index(SearchIndexSchema::from(opts))
    }

    /// 删除索引（FT.DROPINDEX）
    pub fn drop_index(&mut self, index_name: &str, dd: bool) -> Result<Vec<HipStr<'static>>> {
        let resolved = self.resolve_index_name(index_name).to_string();
        let name_to_remove = HipStr::from(resolved);

        let removed = self.indexes.remove(&name_to_remove);
        if let Some((_, inverted)) = removed {
            // 清理对应的别名
            self.aliases
                .retain(|_, target| target.as_str() != name_to_remove.as_str());

            if dd {
                let doc_ids: Vec<HipStr<'static>> = inverted.docs.keys().cloned().collect();
                Ok(doc_ids)
            } else {
                Ok(Vec::new())
            }
        } else {
            Err(Error::invalid_data(format!("Unknown index '{index_name}'")))
        }
    }

    /// 获取索引及其倒排表引用
    pub fn get_index(&self, index_name: &str) -> Option<&(SearchIndexSchema, InvertedIndex)> {
        let resolved = self.resolve_index_name(index_name);
        self.indexes.get(resolved)
    }

    /// 获取索引及其倒排表可变引用
    pub fn get_index_mut(
        &mut self,
        index_name: &str,
    ) -> Option<&mut (SearchIndexSchema, InvertedIndex)> {
        let resolved = self.resolve_index_name(index_name);
        let key = HipStr::from(resolved);
        self.indexes.get_mut(&key)
    }

    /// 列出所有索引名称（FT._LIST）
    pub fn list_indexes(&self) -> Vec<String> {
        let mut list: Vec<String> = self.indexes.keys().map(|k| k.to_string()).collect();
        list.sort();
        list
    }

    /// 解析索引名称（支持别名解析）
    pub fn resolve_index_name<'a>(&'a self, alias_or_name: &'a str) -> &'a str {
        if let Some(target) = self.aliases.get(alias_or_name) {
            target.as_str()
        } else {
            alias_or_name
        }
    }

    /// 添加别名（FT.ALIASADD）
    pub fn add_alias(&mut self, alias: &str, index_name: &str) -> Result<()> {
        let alias_key = HipStr::from(alias);
        if self.aliases.contains_key(&alias_key) {
            return Err(Error::invalid_data(format!(
                "Alias '{alias}' already exists"
            )));
        }
        if !self.indexes.contains_key(index_name) {
            return Err(Error::invalid_data(format!(
                "Index '{index_name}' not found"
            )));
        }
        self.aliases.insert(alias_key, HipStr::from(index_name));
        Ok(())
    }

    /// 删除别名（FT.ALIASDEL）
    pub fn del_alias(&mut self, alias: &str) -> Result<()> {
        let alias_key = HipStr::from(alias);
        if self.aliases.remove(&alias_key).is_none() {
            return Err(Error::invalid_data(format!("Alias '{alias}' not found")));
        }
        Ok(())
    }

    /// 更新别名（FT.ALIASUPDATE）
    pub fn update_alias(&mut self, alias: &str, index_name: &str) -> Result<()> {
        if !self.indexes.contains_key(index_name) {
            return Err(Error::invalid_data(format!(
                "Index '{index_name}' not found"
            )));
        }
        self.aliases
            .insert(HipStr::from(alias), HipStr::from(index_name));
        Ok(())
    }

    /// 获取标签字段值列表（FT.TAGVALS）
    pub fn tag_vals(&self, index_name: &str, field_name: &str) -> Result<Vec<String>> {
        if let Some((_, idx)) = self.get_index(index_name) {
            Ok(idx.tag_vals(field_name))
        } else {
            Err(Error::invalid_data(format!(
                "Index '{index_name}' not found"
            )))
        }
    }

    /// 执行检索（FT.SEARCH）
    pub fn search(&self, index_name: &str, query: &str, opts: &FtSearch) -> Result<SearchResult> {
        if let Some((schema, idx)) = self.get_index(index_name) {
            idx.search(schema, query, opts)
        } else {
            Err(Error::invalid_data(format!(
                "Index '{index_name}' not found"
            )))
        }
    }

    /// 查询执行计划（FT.EXPLAIN）
    pub fn explain(&self, query: &str, opts: &FtSearch) -> String {
        let ast = parse_search_query_with_params(query, &opts.params);
        explain_search_query(&ast)
    }

    /// 查询 CLI 执行计划（FT.EXPLAINCLI）
    pub fn explain_cli(&self, query: &str, opts: &FtSearch) -> String {
        let ast = parse_search_query_with_params(query, &opts.params);
        explain_search_query_cli(&ast)
    }

    /// 获取索引信息（FT.INFO）
    pub fn info(&self, index_name: &str) -> Result<FtInfo> {
        if let Some((schema, idx)) = self.get_index(index_name) {
            Ok(idx.info(schema))
        } else {
            Err(Error::invalid_data(format!(
                "Index '{index_name}' not found"
            )))
        }
    }

    /// FT.CONFIG GET
    pub fn config_get(&self, option: &str) -> Result<String> {
        let opt_upper = option.to_ascii_uppercase();
        if let Some(val) = self.configs.get(&opt_upper) {
            Ok(val.clone())
        } else {
            Err(Error::invalid_data(format!(
                "No such configuration option '{option}'"
            )))
        }
    }

    /// FT.CONFIG SET
    pub fn config_set(&mut self, option: &str, value: &str) -> Result<()> {
        let opt_upper = option.to_ascii_uppercase();
        self.configs.insert(opt_upper, value.to_string());
        Ok(())
    }

    /// FT.CONFIG HELP
    pub fn config_help(&self, option: &str) -> Result<String> {
        let opt_upper = option.to_ascii_uppercase();
        match opt_upper.as_str() {
            "TIMEOUT" => Ok("Query execution timeout in milliseconds".to_string()),
            "DEFAULT_DIALECT" => Ok("Default RediSearch dialect version".to_string()),
            "MINPREFIX" => Ok("Minimum prefix length for wildcard expansion".to_string()),
            "MAXEXPANSIONS" => Ok("Maximum number of prefix expansions".to_string()),
            _ => Ok(format!("Help information for {option}")),
        }
    }

    /// FT.SUGADD
    pub fn sug_add(
        &mut self,
        key: &str,
        string: &str,
        score: f64,
        incr: bool,
        payload: Option<String>,
    ) -> usize {
        let dict = self.suggestions.entry(HipStr::from(key)).or_default();
        dict.sug_add(string, score, incr, payload)
    }

    /// FT.SUGGET
    pub fn sug_get(
        &self,
        key: &str,
        prefix: &str,
        fuzzy: bool,
        withscores: bool,
        withpayloads: bool,
        max: Option<usize>,
    ) -> Vec<SuggestionItem> {
        if let Some(dict) = self.suggestions.get(key) {
            dict.sug_get(prefix, fuzzy, withscores, withpayloads, max)
        } else {
            Vec::new()
        }
    }

    /// FT.SUGDEL
    pub fn sug_del(&mut self, key: &str, string: &str) -> bool {
        if let Some(dict) = self.suggestions.get_mut(key) {
            dict.sug_del(string)
        } else {
            false
        }
    }

    /// FT.SUGLEN
    pub fn sug_len(&self, key: &str) -> usize {
        if let Some(dict) = self.suggestions.get(key) {
            dict.sug_len()
        } else {
            0
        }
    }
}