#ifndef NSIGNER_CRYPTO_H
#define NSIGNER_CRYPTO_H

#include "role_table.h"
#include "secure_mem.h"
#include "mnemonic.h"
#include <cJSON.h>

/* Per-role derived key material (stored in secure memory) */
typedef struct {
    secure_buf_t private_key;  /* 32 bytes, mlock'd */
    unsigned char public_key[32];
    char pubkey_hex[65];       /* 64 hex chars + null */
    char npub[128];            /* bech32 npub */
    int valid;
} derived_key_t;

/* Key store — holds derived keys for all roles */
typedef struct {
    derived_key_t keys[ROLE_TABLE_MAX_ENTRIES];
    int count;
} key_store_t;

/* Initialize crypto subsystem (calls nostr_init). Returns 0 on success. */
int crypto_init(void);

/* Cleanup crypto subsystem (calls nostr_cleanup). */
void crypto_cleanup(void);

/* Derive keys for all roles in the table using the loaded mnemonic.
 * Populates key_store and sets role->pubkey_hex and role->derived for each role.
 * Only derives for roles with purpose=nostr and curve=secp256k1 (for now).
 * Returns number of keys derived, or -1 on error. */
int crypto_derive_all(key_store_t *store, role_table_t *table, const mnemonic_state_t *mnemonic);

/* Get the derived private key for a role (by table index). Returns NULL if not derived. */
const unsigned char *crypto_get_private_key(const key_store_t *store, int role_index);

/* Get the derived public key hex for a role. Returns NULL if not derived. */
const char *crypto_get_pubkey_hex(const key_store_t *store, int role_index);

/* Sign a Nostr event. event_json is the unsigned event JSON string.
 * Returns a newly-allocated string containing the signed event JSON, or NULL on error.
 * Caller must free() the returned string. */
char *crypto_sign_event(const key_store_t *store, int role_index, const char *event_json);

/* NIP-44 encrypt. Returns newly-allocated ciphertext string, or NULL on error. Caller frees. */
char *crypto_nip44_encrypt(const key_store_t *store, int role_index,
                           const char *recipient_pubkey_hex, const char *plaintext);

/* NIP-44 decrypt. Returns newly-allocated plaintext string, or NULL on error. Caller frees. */
char *crypto_nip44_decrypt(const key_store_t *store, int role_index,
                           const char *sender_pubkey_hex, const char *ciphertext);

/* NIP-04 encrypt. Returns newly-allocated ciphertext string, or NULL on error. Caller frees. */
char *crypto_nip04_encrypt(const key_store_t *store, int role_index,
                           const char *recipient_pubkey_hex, const char *plaintext);

/* NIP-04 decrypt. Returns newly-allocated plaintext string, or NULL on error. Caller frees. */
char *crypto_nip04_decrypt(const key_store_t *store, int role_index,
                           const char *sender_pubkey_hex, const char *ciphertext);

/* Zeroize all derived keys in the store. */
void crypto_wipe(key_store_t *store);

#endif /* NSIGNER_CRYPTO_H */