use rhai::{Engine, Scope, Dynamic, FnPtr};
use webassembly::core::keypair;
use webassembly::core::symmetric;
use webassembly::core::ethereum;
use webassembly::core::error::CryptoError;
use std::str::FromStr;
use base64::{Engine as _, engine::general_purpose::STANDARD as BASE64};

use std::fs;
use std::path::PathBuf;

// Key space management functions
fn load_key_space(name: &str, password: &str) -> bool {
    // Get the key spaces directory from config
    let home_dir = dirs::home_dir().unwrap_or_else(|| PathBuf::from("."));
    let key_spaces_dir = home_dir.join(".hero-vault").join("key-spaces");
    
    // Check if directory exists
    if !key_spaces_dir.exists() {
        println!("Key spaces directory does not exist");
        return false;
    }
    
    // Get the key space file path
    let space_path = key_spaces_dir.join(format!("{}.json", name));
    
    // Check if file exists
    if !space_path.exists() {
        println!("Key space file not found: {}", space_path.display());
        return false;
    }
    
    // Read the file
    let serialized = match fs::read_to_string(&space_path) {
        Ok(data) => data,
        Err(e) => {
            println!("Error reading key space file: {}", e);
            return false;
        }
    };
    
    // Deserialize the encrypted space
    let encrypted_space = match symmetric::deserialize_encrypted_space(&serialized) {
        Ok(space) => space,
        Err(e) => {
            println!("Error deserializing key space: {}", e);
            return false;
        }
    };
    
    // Decrypt the space
    let space = match symmetric::decrypt_key_space(&encrypted_space, password) {
        Ok(space) => space,
        Err(e) => {
            println!("Error decrypting key space: {}", e);
            return false;
        }
    };
    
    // Set as current space
    match keypair::set_current_space(space) {
        Ok(_) => true,
        Err(e) => {
            println!("Error setting current space: {}", e);
            false
        }
    }
}

fn create_key_space(name: &str, password: &str) -> bool {
    match keypair::create_space(name) {
        Ok(_) => {
            // Get the current space
            match keypair::get_current_space() {
                Ok(space) => {
                    // Encrypt the key space
                    let encrypted_space = match symmetric::encrypt_key_space(&space, password) {
                        Ok(encrypted) => encrypted,
                        Err(e) => {
                            println!("Error encrypting key space: {}", e);
                            return false;
                        }
                    };
                    
                    // Serialize the encrypted space
                    let serialized = match symmetric::serialize_encrypted_space(&encrypted_space) {
                        Ok(json) => json,
                        Err(e) => {
                            println!("Error serializing encrypted space: {}", e);
                            return false;
                        }
                    };
                    
                    // Get the key spaces directory
                    let home_dir = dirs::home_dir().unwrap_or_else(|| PathBuf::from("."));
                    let key_spaces_dir = home_dir.join(".hero-vault").join("key-spaces");
                    
                    // Create directory if it doesn't exist
                    if !key_spaces_dir.exists() {
                        match fs::create_dir_all(&key_spaces_dir) {
                            Ok(_) => {},
                            Err(e) => {
                                println!("Error creating key spaces directory: {}", e);
                                return false;
                            }
                        }
                    }
                    
                    // Write to file
                    let space_path = key_spaces_dir.join(format!("{}.json", name));
                    match fs::write(&space_path, serialized) {
                        Ok(_) => {
                            println!("Key space created and saved to {}", space_path.display());
                            true
                        },
                        Err(e) => {
                            println!("Error writing key space file: {}", e);
                            false
                        }
                    }
                },
                Err(e) => {
                    println!("Error getting current space: {}", e);
                    false
                }
            }
        },
        Err(e) => {
            println!("Error creating key space: {}", e);
            false
        }
    }
}

// Auto-save function for internal use
fn auto_save_key_space(password: &str) -> bool {
    match keypair::get_current_space() {
        Ok(space) => {
            // Encrypt the key space
            let encrypted_space = match symmetric::encrypt_key_space(&space, password) {
                Ok(encrypted) => encrypted,
                Err(e) => {
                    println!("Error encrypting key space: {}", e);
                    return false;
                }
            };
            
            // Serialize the encrypted space
            let serialized = match symmetric::serialize_encrypted_space(&encrypted_space) {
                Ok(json) => json,
                Err(e) => {
                    println!("Error serializing encrypted space: {}", e);
                    return false;
                }
            };
            
            // Get the key spaces directory
            let home_dir = dirs::home_dir().unwrap_or_else(|| PathBuf::from("."));
            let key_spaces_dir = home_dir.join(".hero-vault").join("key-spaces");
            
            // Create directory if it doesn't exist
            if !key_spaces_dir.exists() {
                match fs::create_dir_all(&key_spaces_dir) {
                    Ok(_) => {},
                    Err(e) => {
                        println!("Error creating key spaces directory: {}", e);
                        return false;
                    }
                }
            }
            
            // Write to file
            let space_path = key_spaces_dir.join(format!("{}.json", space.name));
            match fs::write(&space_path, serialized) {
                Ok(_) => {
                    println!("Key space saved to {}", space_path.display());
                    true
                },
                Err(e) => {
                    println!("Error writing key space file: {}", e);
                    false
                }
            }
        },
        Err(e) => {
            println!("Error getting current space: {}", e);
            false
        }
    }
}

fn encrypt_key_space(password: &str) -> String {
    match keypair::get_current_space() {
        Ok(space) => {
            match symmetric::encrypt_key_space(&space, password) {
                Ok(encrypted_space) => {
                    match serde_json::to_string(&encrypted_space) {
                        Ok(json) => json,
                        Err(e) => {
                            println!("Error serializing encrypted space: {}", e);
                            String::new()
                        }
                    }
                },
                Err(e) => {
                    println!("Error encrypting key space: {}", e);
                    String::new()
                }
            }
        },
        Err(e) => {
            println!("Error getting current space: {}", e);
            String::new()
        }
    }
}

fn decrypt_key_space(encrypted: &str, password: &str) -> bool {
    match serde_json::from_str(encrypted) {
        Ok(encrypted_space) => {
            match symmetric::decrypt_key_space(&encrypted_space, password) {
                Ok(space) => {
                    match keypair::set_current_space(space) {
                        Ok(_) => true,
                        Err(e) => {
                            println!("Error setting current space: {}", e);
                            false
                        }
                    }
                },
                Err(e) => {
                    println!("Error decrypting key space: {}", e);
                    false
                }
            }
        },
        Err(e) => {
            println!("Error parsing encrypted space: {}", e);
            false
        }
    }
}

// Keypair management functions
fn create_keypair(name: &str, password: &str) -> bool {
    match keypair::create_keypair(name) {
        Ok(_) => {
            // Auto-save the key space after creating a keypair
            auto_save_key_space(password)
        },
        Err(e) => {
            println!("Error creating keypair: {}", e);
            false
        }
    }
}

fn select_keypair(name: &str) -> bool {
    match keypair::select_keypair(name) {
        Ok(_) => true,
        Err(e) => {
            println!("Error selecting keypair: {}", e);
            false
        }
    }
}

fn list_keypairs() -> Vec<String> {
    match keypair::list_keypairs() {
        Ok(keypairs) => keypairs,
        Err(e) => {
            println!("Error listing keypairs: {}", e);
            Vec::new()
        }
    }
}

// Cryptographic operations
fn sign(message: &str) -> String {
    let message_bytes = message.as_bytes();
    match keypair::keypair_sign(message_bytes) {
        Ok(signature) => BASE64.encode(signature),
        Err(e) => {
            println!("Error signing message: {}", e);
            String::new()
        }
    }
}

fn verify(message: &str, signature: &str) -> bool {
    let message_bytes = message.as_bytes();
    match BASE64.decode(signature) {
        Ok(signature_bytes) => {
            match keypair::keypair_verify(message_bytes, &signature_bytes) {
                Ok(is_valid) => is_valid,
                Err(e) => {
                    println!("Error verifying signature: {}", e);
                    false
                }
            }
        },
        Err(e) => {
            println!("Error decoding signature: {}", e);
            false
        }
    }
}

// Symmetric encryption
fn generate_key() -> String {
    let key = symmetric::generate_symmetric_key();
    BASE64.encode(key)
}

fn encrypt(key: &str, message: &str) -> String {
    match BASE64.decode(key) {
        Ok(key_bytes) => {
            let message_bytes = message.as_bytes();
            match symmetric::encrypt_symmetric(&key_bytes, message_bytes) {
                Ok(ciphertext) => BASE64.encode(ciphertext),
                Err(e) => {
                    println!("Error encrypting message: {}", e);
                    String::new()
                }
            }
        },
        Err(e) => {
            println!("Error decoding key: {}", e);
            String::new()
        }
    }
}

fn decrypt(key: &str, ciphertext: &str) -> String {
    match BASE64.decode(key) {
        Ok(key_bytes) => {
            match BASE64.decode(ciphertext) {
                Ok(ciphertext_bytes) => {
                    match symmetric::decrypt_symmetric(&key_bytes, &ciphertext_bytes) {
                        Ok(plaintext) => {
                            match String::from_utf8(plaintext) {
                                Ok(text) => text,
                                Err(e) => {
                                    println!("Error converting plaintext to string: {}", e);
                                    String::new()
                                }
                            }
                        },
                        Err(e) => {
                            println!("Error decrypting ciphertext: {}", e);
                            String::new()
                        }
                    }
                },
                Err(e) => {
                    println!("Error decoding ciphertext: {}", e);
                    String::new()
                }
            }
        },
        Err(e) => {
            println!("Error decoding key: {}", e);
            String::new()
        }
    }
}

// Ethereum operations
fn create_ethereum_wallet() -> bool {
    match ethereum::create_ethereum_wallet() {
        Ok(_) => true,
        Err(e) => {
            println!("Error creating Ethereum wallet: {}", e);
            false
        }
    }
}

fn get_ethereum_address() -> String {
    match ethereum::get_current_ethereum_wallet() {
        Ok(wallet) => wallet.address_string(),
        Err(e) => {
            println!("Error getting Ethereum address: {}", e);
            String::new()
        }
    }
}

pub fn register_crypto_api(engine: &mut Engine, scope: &mut Scope<'_>) {
    // Register key space functions
    engine.register_fn("load_key_space", load_key_space);
    engine.register_fn("create_key_space", create_key_space);
    engine.register_fn("encrypt_key_space", encrypt_key_space);
    engine.register_fn("decrypt_key_space", decrypt_key_space);
    
    // Register keypair functions
    engine.register_fn("create_keypair", create_keypair);
    engine.register_fn("select_keypair", select_keypair);
    engine.register_fn("list_keypairs", list_keypairs);
    
    // Register signing/verification functions
    engine.register_fn("sign", sign);
    engine.register_fn("verify", verify);
    
    // Register symmetric encryption functions
    engine.register_fn("generate_key", generate_key);
    engine.register_fn("encrypt", encrypt);
    engine.register_fn("decrypt", decrypt);
    
    // Register Ethereum functions
    engine.register_fn("create_ethereum_wallet", create_ethereum_wallet);
    engine.register_fn("get_ethereum_address", get_ethereum_address);
    
    // Add any additional functions or variables to the scope
    scope.push("VERSION", "1.0.0");
}