use std::{
    path::Path,
    sync::Arc,
    time::{SystemTime, UNIX_EPOCH},
};

use redb::{Database, TableDefinition};
use serde::{Deserialize, Serialize};

use crate::crypto::CryptoFactory;
use crate::error::DBError;

// Re-export modules
mod storage_basic;
mod storage_hset;
mod storage_lists;
mod storage_extra;

// Re-export implementations
// Note: These imports are used by the impl blocks in the submodules
// The compiler shows them as unused because they're not directly used in this file
// but they're needed for the Storage struct methods to be available
pub use storage_extra::*;

// Table definitions for different Redis data types
const TYPES_TABLE: TableDefinition<&str, &str> = TableDefinition::new("types");
const STRINGS_TABLE: TableDefinition<&str, &[u8]> = TableDefinition::new("strings");
const HASHES_TABLE: TableDefinition<(&str, &str), &[u8]> = TableDefinition::new("hashes");
const LISTS_TABLE: TableDefinition<&str, &[u8]> = TableDefinition::new("lists");
const STREAMS_META_TABLE: TableDefinition<&str, &[u8]> = TableDefinition::new("streams_meta");
const STREAMS_DATA_TABLE: TableDefinition<(&str, &str), &[u8]> = TableDefinition::new("streams_data");
const ENCRYPTED_TABLE: TableDefinition<&str, u8> = TableDefinition::new("encrypted");
const EXPIRATION_TABLE: TableDefinition<&str, u64> = TableDefinition::new("expiration");

#[derive(Serialize, Deserialize, Debug, Clone)]
pub struct StreamEntry {
    pub fields: Vec<(String, String)>,
}

#[derive(Serialize, Deserialize, Debug, Clone)]
pub struct ListValue {
    pub elements: Vec<String>,
}

#[inline]
pub fn now_in_millis() -> u128 {
    let start = SystemTime::now();
    let duration_since_epoch = start.duration_since(UNIX_EPOCH).unwrap();
    duration_since_epoch.as_millis()
}

pub struct Storage {
    db: Database,
    crypto: Option<CryptoFactory>,
}

impl Storage {
    pub fn new(path: impl AsRef<Path>, should_encrypt: bool, master_key: Option<&str>) -> Result<Self, DBError> {
        let db = Database::create(path)?;
        
        // Create tables if they don't exist
        let write_txn = db.begin_write()?;
        {
            let _ = write_txn.open_table(TYPES_TABLE)?;
            let _ = write_txn.open_table(STRINGS_TABLE)?;
            let _ = write_txn.open_table(HASHES_TABLE)?;
            let _ = write_txn.open_table(LISTS_TABLE)?;
            let _ = write_txn.open_table(STREAMS_META_TABLE)?;
            let _ = write_txn.open_table(STREAMS_DATA_TABLE)?;
            let _ = write_txn.open_table(ENCRYPTED_TABLE)?;
            let _ = write_txn.open_table(EXPIRATION_TABLE)?;
        }
        write_txn.commit()?;
        
        // Check if database was previously encrypted
        let read_txn = db.begin_read()?;
        let encrypted_table = read_txn.open_table(ENCRYPTED_TABLE)?;
        let was_encrypted = encrypted_table.get("encrypted")?.map(|v| v.value() == 1).unwrap_or(false);
        drop(read_txn);
        
        let crypto = if should_encrypt || was_encrypted {
            if let Some(key) = master_key {
                Some(CryptoFactory::new(key.as_bytes()))
            } else {
                return Err(DBError("Encryption requested but no master key provided".to_string()));
            }
        } else {
            None
        };
        
        // If we're enabling encryption for the first time, mark it
        if should_encrypt && !was_encrypted {
            let write_txn = db.begin_write()?;
            {
                let mut encrypted_table = write_txn.open_table(ENCRYPTED_TABLE)?;
                encrypted_table.insert("encrypted", &1u8)?;
            }
            write_txn.commit()?;
        }
        
        Ok(Storage {
            db,
            crypto,
        })
    }
    
    pub fn is_encrypted(&self) -> bool {
        self.crypto.is_some()
    }

    // Helper methods for encryption
    fn encrypt_if_needed(&self, data: &[u8]) -> Result<Vec<u8>, DBError> {
        if let Some(crypto) = &self.crypto {
            Ok(crypto.encrypt(data))
        } else {
            Ok(data.to_vec())
        }
    }
    
    fn decrypt_if_needed(&self, data: &[u8]) -> Result<Vec<u8>, DBError> {
        if let Some(crypto) = &self.crypto {
            Ok(crypto.decrypt(data)?)
        } else {
            Ok(data.to_vec())
        }
    }
}

use crate::storage_trait::StorageBackend;

impl StorageBackend for Storage {
    fn get(&self, key: &str) -> Result<Option<String>, DBError> {
        self.get(key)
    }

    fn set(&self, key: String, value: String) -> Result<(), DBError> {
        self.set(key, value)
    }

    fn setx(&self, key: String, value: String, expire_ms: u128) -> Result<(), DBError> {
        self.setx(key, value, expire_ms)
    }

    fn del(&self, key: String) -> Result<(), DBError> {
        self.del(key)
    }

    fn exists(&self, key: &str) -> Result<bool, DBError> {
        self.exists(key)
    }

    fn keys(&self, pattern: &str) -> Result<Vec<String>, DBError> {
        self.keys(pattern)
    }

    fn dbsize(&self) -> Result<i64, DBError> {
        self.dbsize()
    }

    fn flushdb(&self) -> Result<(), DBError> {
        self.flushdb()
    }

    fn get_key_type(&self, key: &str) -> Result<Option<String>, DBError> {
        self.get_key_type(key)
    }

    fn scan(&self, cursor: u64, pattern: Option<&str>, count: Option<u64>) -> Result<(u64, Vec<(String, String)>), DBError> {
        self.scan(cursor, pattern, count)
    }

    fn hscan(&self, key: &str, cursor: u64, pattern: Option<&str>, count: Option<u64>) -> Result<(u64, Vec<(String, String)>), DBError> {
        self.hscan(key, cursor, pattern, count)
    }

    fn hset(&self, key: &str, pairs: Vec<(String, String)>) -> Result<i64, DBError> {
        self.hset(key, pairs)
    }

    fn hget(&self, key: &str, field: &str) -> Result<Option<String>, DBError> {
        self.hget(key, field)
    }

    fn hgetall(&self, key: &str) -> Result<Vec<(String, String)>, DBError> {
        self.hgetall(key)
    }

    fn hdel(&self, key: &str, fields: Vec<String>) -> Result<i64, DBError> {
        self.hdel(key, fields)
    }

    fn hexists(&self, key: &str, field: &str) -> Result<bool, DBError> {
        self.hexists(key, field)
    }

    fn hkeys(&self, key: &str) -> Result<Vec<String>, DBError> {
        self.hkeys(key)
    }

    fn hvals(&self, key: &str) -> Result<Vec<String>, DBError> {
        self.hvals(key)
    }

    fn hlen(&self, key: &str) -> Result<i64, DBError> {
        self.hlen(key)
    }

    fn hmget(&self, key: &str, fields: Vec<String>) -> Result<Vec<Option<String>>, DBError> {
        self.hmget(key, fields)
    }

    fn hsetnx(&self, key: &str, field: &str, value: &str) -> Result<bool, DBError> {
        self.hsetnx(key, field, value)
    }

    fn lpush(&self, key: &str, elements: Vec<String>) -> Result<i64, DBError> {
        self.lpush(key, elements)
    }

    fn rpush(&self, key: &str, elements: Vec<String>) -> Result<i64, DBError> {
        self.rpush(key, elements)
    }

    fn lpop(&self, key: &str, count: u64) -> Result<Vec<String>, DBError> {
        self.lpop(key, count)
    }

    fn rpop(&self, key: &str, count: u64) -> Result<Vec<String>, DBError> {
        self.rpop(key, count)
    }

    fn llen(&self, key: &str) -> Result<i64, DBError> {
        self.llen(key)
    }

    fn lindex(&self, key: &str, index: i64) -> Result<Option<String>, DBError> {
        self.lindex(key, index)
    }

    fn lrange(&self, key: &str, start: i64, stop: i64) -> Result<Vec<String>, DBError> {
        self.lrange(key, start, stop)
    }

    fn ltrim(&self, key: &str, start: i64, stop: i64) -> Result<(), DBError> {
        self.ltrim(key, start, stop)
    }

    fn lrem(&self, key: &str, count: i64, element: &str) -> Result<i64, DBError> {
        self.lrem(key, count, element)
    }

    fn ttl(&self, key: &str) -> Result<i64, DBError> {
        self.ttl(key)
    }

    fn expire_seconds(&self, key: &str, secs: u64) -> Result<bool, DBError> {
        self.expire_seconds(key, secs)
    }

    fn pexpire_millis(&self, key: &str, ms: u128) -> Result<bool, DBError> {
        self.pexpire_millis(key, ms)
    }

    fn persist(&self, key: &str) -> Result<bool, DBError> {
        self.persist(key)
    }

    fn expire_at_seconds(&self, key: &str, ts_secs: i64) -> Result<bool, DBError> {
        self.expire_at_seconds(key, ts_secs)
    }

    fn pexpire_at_millis(&self, key: &str, ts_ms: i64) -> Result<bool, DBError> {
        self.pexpire_at_millis(key, ts_ms)
    }

    fn is_encrypted(&self) -> bool {
        self.is_encrypted()
    }
    
    fn info(&self) -> Result<Vec<(String, String)>, DBError> {
        self.info()
    }

    fn clone_arc(&self) -> Arc<dyn StorageBackend> {
        unimplemented!("Storage cloning not yet implemented for redb backend")
    }
}