// This file is under GNU General Public License 3.0

// see LICENSE.txt

#include "pEp_internal.h"

#include "dynamic_api.h"

#include "message_api.h"

#include <string.h>

#include <stdlib.h>

PEP_STATUS has_key_reset_been_sent(

        PEP_SESSION session, 

        const char* user_id, 

        const char* revoked_fpr,

        bool* contacted)

{

    assert(session);

    assert(contacted);

    assert(user_id);

    assert(revoked_fpr);

    assert(!EMPTYSTR(user_id));

    if (!session || !contacted || EMPTYSTR(revoked_fpr) || EMPTYSTR(user_id))

        return PEP_ILLEGAL_VALUE;

    *contacted = false;

    char* alias_default = NULL;

    PEP_STATUS status = get_userid_alias_default(session, user_id, &alias_default);

    if (status == PEP_CANNOT_FIND_ALIAS || EMPTYSTR(alias_default)) {

        free(alias_default);

        alias_default = strdup(user_id);

    }

    sqlite3_reset(session->was_id_for_revoke_contacted);

    sqlite3_bind_text(session->was_id_for_revoke_contacted, 1, revoked_fpr, -1,

            SQLITE_STATIC);

    sqlite3_bind_text(session->was_id_for_revoke_contacted, 2, user_id, -1,

            SQLITE_STATIC);        

    int result = sqlite3_step(session->was_id_for_revoke_contacted);

    switch (result) {

        case SQLITE_ROW: {

            *contacted = (sqlite3_column_int(session->was_id_for_revoke_contacted, 0) != 0);

            break;

        }

        default:

            sqlite3_reset(session->was_id_for_revoke_contacted);

            free(alias_default);

            return PEP_UNKNOWN_DB_ERROR;

    }

    sqlite3_reset(session->was_id_for_revoke_contacted);

    return PEP_STATUS_OK;

}

//static const char *sql_set_revoke_contact_as_notified =

//    "insert or replace into revocation_contact_list(fpr, contact_id) values (?1, ?2) ;";

PEP_STATUS set_reset_contact_notified(

        PEP_SESSION session,

        const char* revoke_fpr,

        const char* contact_id

    )

{

    PEP_STATUS status = PEP_STATUS_OK;

    assert(session && !EMPTYSTR(revoke_fpr) && !EMPTYSTR(contact_id));

    if (!session || EMPTYSTR(revoke_fpr) || EMPTYSTR(contact_id))

        return PEP_ILLEGAL_VALUE;

    sqlite3_reset(session->set_revoke_contact_as_notified);

    sqlite3_bind_text(session->set_revoke_contact_as_notified, 1, revoke_fpr, -1, 

            SQLITE_STATIC);

    sqlite3_bind_text(session->set_revoke_contact_as_notified, 2, contact_id, -1,

            SQLITE_STATIC);

    int result;

    result = sqlite3_step(session->set_revoke_contact_as_notified);

    switch (result) {

        case SQLITE_DONE:

            status = PEP_STATUS_OK;

            break;

        default:

            status = PEP_UNKNOWN_DB_ERROR;

    }

    sqlite3_reset(session->set_revoke_contact_as_notified);

    return status;    

}

PEP_STATUS receive_key_reset(PEP_SESSION session,

                             message* reset_msg) {

    if (!session || !reset_msg)

        return PEP_ILLEGAL_VALUE;

    pEp_identity* sender_id = reset_msg->from;

    if (!sender_id)

        return PEP_MALFORMED_KEY_RESET_MSG;

    PEP_STATUS status = update_identity(session, sender_id);

    if (!sender_id->user_id)

        return PEP_UNKNOWN_ERROR;

    if (is_me(session, sender_id))

        return PEP_ILLEGAL_VALUE;    

    if (!reset_msg->longmsg || strncmp(reset_msg->longmsg, "OLD: ", 5) != 0) 

        return PEP_MALFORMED_KEY_RESET_MSG;

    status = PEP_STATUS_OK;

    char* old_fpr = NULL;

    char* new_fpr = NULL;

    stringlist_t* keylist = NULL;

    pEp_identity* temp_ident = identity_dup(sender_id);

    if (!temp_ident) {

        status = PEP_OUT_OF_MEMORY;

        goto pep_free;

    }        

    char* rest = NULL;

    char* p = strtok_r(reset_msg->longmsg, "\r\n", &rest);

    if (!EMPTYSTR(p + 5))

        old_fpr = strdup(p + 5);

    else {

        status = PEP_MALFORMED_KEY_RESET_MSG;

        goto pep_free;

    }

    bool own_key = false;

    status = is_own_key(session, old_fpr, &own_key);

    if (own_key) {

        // Nope, no one can make us our own default. If we want to do that,

        // that's keysync, NOT key reset.

        status = PEP_ILLEGAL_VALUE;

        goto pep_free;

    }

    p = strtok_r(NULL, "\r\n", &rest); 

    if (strncmp(p, "NEW: ", 5) != 0  || EMPTYSTR(p + 5)) {

        status = PEP_MALFORMED_KEY_RESET_MSG;

        goto pep_free;

    }

    new_fpr = strdup(p + 5);

    // Reset the original key

    status = key_reset(session, old_fpr, temp_ident);

    if (status != PEP_STATUS_OK)

        goto pep_free;

    status = find_keys(session, new_fpr, &keylist);

    if (status != PEP_STATUS_OK)

        goto pep_free;

    if (!keylist) {

        status = PEP_KEY_NOT_FOUND;

        goto pep_free;

    }

    // alright, we've checked as best we can. Let's set that baby.

    sender_id->fpr = new_fpr;

    // This only sets as the default, does NOT TRUST IN ANY WAY

    sender_id->comm_type = sender_id->comm_type & (~PEP_ct_confirmed);

    status = set_identity(session, sender_id);

    sender_id->fpr = NULL; // ownership for free

pep_free:    

    free_stringlist(keylist);    

    free(old_fpr);

    free(new_fpr);

    free_identity(temp_ident);

    return status;

}

PEP_STATUS create_standalone_key_reset_message(PEP_SESSION session,

                                               message** dst, 

                                               pEp_identity* recip,

                                               const char* old_fpr,

                                               const char* new_fpr) {

    if (!dst || !recip->user_id || !recip->address)

        return PEP_ILLEGAL_VALUE;

    if (!old_fpr || !new_fpr)

        return PEP_ILLEGAL_VALUE;

    *dst = NULL;

    // Get own identity user has corresponded with

    pEp_identity* own_identity = NULL;

    PEP_STATUS status = get_own_ident_for_contact_id(session,

                                                     recip,

                                                     &own_identity);                                                       

    if (status != PEP_STATUS_OK)

        return status;

    message* reset_message = new_message(PEP_dir_outgoing);

    reset_message->from = own_identity;

    reset_message->to = new_identity_list(identity_dup(recip)); // ?

    const char* oldtag = "OLD: ";

    const char* newtag = "\nNEW: ";

    const size_t taglens = 11;

    size_t full_len = taglens + strlen(old_fpr) + strlen(new_fpr) + 2; // \n and \0

    char* longmsg = calloc(full_len, 1);

    strlcpy(longmsg, oldtag, full_len);

    strlcat(longmsg, old_fpr, full_len);

    strlcat(longmsg, newtag, full_len);

    strlcat(longmsg, new_fpr, full_len);

    strlcat(longmsg, "\n", full_len);

    reset_message->longmsg = longmsg; 

    reset_message->shortmsg = strdup("Key reset");    

    message* output_msg = NULL;

    status = encrypt_message(session, reset_message, NULL,

                             &output_msg, PEP_enc_PGP_MIME,

                             PEP_encrypt_flag_key_reset_only);

    if (status == PEP_STATUS_OK)

        *dst = output_msg;

    free_message(reset_message);

    return status;

}

PEP_STATUS send_key_reset_to_recents(PEP_SESSION session,

                                     const char* old_fpr, 

                                     const char* new_fpr) {

    assert(old_fpr);

    assert(new_fpr);

    assert(session);

    assert(session->messageToSend || session->sync_session->messageToSend);

    if (!session || !old_fpr || !new_fpr)

        return PEP_ILLEGAL_VALUE;

    messageToSend_t send_cb = send_cb = session->messageToSend;

    void* sync_obj = session->sync_obj;

    if (!send_cb) {

        send_cb = session->sync_session->messageToSend;

        sync_obj = session->sync_session->sync_obj;

    }

    if (!send_cb)

        return PEP_SYNC_NO_MESSAGE_SEND_CALLBACK;

    identity_list* recent_contacts = NULL;

    message* reset_msg = NULL;

    PEP_STATUS status = get_last_contacted(session, &recent_contacts);

    if (status != PEP_STATUS_OK)

        goto pep_free;

    identity_list* curr_id_ptr = recent_contacts;

    for (curr_id_ptr = recent_contacts; curr_id_ptr; curr_id_ptr = curr_id_ptr->next) {

        pEp_identity* curr_id = curr_id_ptr->ident;

        if (!curr_id)

            break;

        const char* user_id = curr_id->user_id;

        // Should be impossible, but?

        if (!user_id)

            continue;

        // Check if it's us - if so, pointless...

        if (is_me(session, curr_id))

            continue;

        // Check if they've already been told - this shouldn't be the case, but...

        bool contacted = false;

        status = has_key_reset_been_sent(session, user_id, old_fpr, &contacted);

        if (status != PEP_STATUS_OK)

            goto pep_free;

        if (contacted)

            continue;

        // if not, make em a message    

        reset_msg = NULL;

        status = create_standalone_key_reset_message(session,

                                                     &reset_msg,

                                                     curr_id,

                                                     old_fpr,

                                                     new_fpr);

        if (status == PEP_CANNOT_FIND_IDENTITY) { // this is ok, just means we never mailed them 

            status = PEP_STATUS_OK;

            continue; 

        }

        if (status != PEP_STATUS_OK) {

            free(reset_msg);

            goto pep_free;

        }

        // insert into queue

        status = send_cb(sync_obj, reset_msg);

        if (status != PEP_STATUS_OK) {

            free(reset_msg);

            goto pep_free;            

        }

        // Put into notified DB

        status = set_reset_contact_notified(session, old_fpr, user_id);

        if (status != PEP_STATUS_OK)

            goto pep_free;            

    }

pep_free:

    free_identity_list(recent_contacts);

    return status;

}

DYNAMIC_API PEP_STATUS key_reset(

        PEP_SESSION session,

        const char* key_id,

        pEp_identity* ident

    )

{

    if (!session)

        return PEP_ILLEGAL_VALUE;

    PEP_STATUS status = PEP_STATUS_OK;

    char* fpr_copy = NULL;

    char* own_id = NULL;

    char* new_key = NULL;

    identity_list* key_idents = NULL;

    stringlist_t* keys = NULL;

    if (!EMPTYSTR(key_id)) {

        fpr_copy = strdup(key_id);

        if (!fpr_copy)

            return PEP_OUT_OF_MEMORY;

    }

    if (!ident) {

        // Get list of own identities

        status = get_default_own_userid(session, &own_id);

        if (status != PEP_STATUS_OK)

            goto pep_free;

        if (EMPTYSTR(fpr_copy)) {

            status = get_all_keys_for_user(session, own_id, &keys);

            if (status == PEP_STATUS_OK) {

                stringlist_t* curr_key;

                for (curr_key = keys; curr_key && curr_key->value; curr_key = curr_key->next) {

                    status = key_reset(session, curr_key->value, NULL);

                    if (status != PEP_STATUS_OK)

                        break;

                }

            }

            goto pep_free;

        } // otherwise, we have a specific fpr to process

        // fpr_copy exists, so... let's go.

        // Process own identities with this fpr

        status = get_identities_by_main_key_id(session, fpr_copy, &key_idents);

        if (status == PEP_STATUS_OK) {

            // have ident list, or should

            identity_list* curr_ident;

            for (curr_ident = key_idents; curr_ident && curr_ident->ident; 

                 curr_ident = curr_ident->next) {

                pEp_identity* this_identity = curr_ident->ident;

                status = key_reset(session, fpr_copy, this_identity);

                if (status != PEP_STATUS_OK)

                    break;                    

            }

        }

        goto pep_free;

    }

    else { // an identity was specified.       

        if (is_me(session, ident)) {            

            // FIXME: make sure this IS our fpr?

            // If it got sent in with an empty fpr...

            if (EMPTYSTR(fpr_copy)) {

                //

                // if (!EMPTYSTR(ident->fpr))

                //     fpr_copy = strdup(ident->fpr);

                status = _myself(session, ident, false, true);

                if (status == PEP_STATUS_OK && ident->fpr)

                    fpr_copy = strdup(ident->fpr);

                else {

                    // last resort?

                    // Get list of own identities

                    char* own_id = NULL;

                    status = get_default_own_userid(session, &own_id);

                    if (status == PEP_STATUS_OK)

                        status = get_user_default_key(session, own_id, &fpr_copy);

                    if (status != PEP_STATUS_OK || EMPTYSTR(fpr_copy))  {

                        free(own_id);

                        return (status == PEP_STATUS_OK ? PEP_KEY_NOT_FOUND : status);

                    }

                }

            }

            free(ident->fpr);

            ident->fpr = fpr_copy;            

            // Create revocation

            status = revoke_key(session, fpr_copy, NULL);

            // generate new key

            if (status == PEP_STATUS_OK) {

                ident->fpr = NULL;

                status = generate_keypair(session, ident);

            }

            if (status == PEP_STATUS_OK) {

                new_key = strdup(ident->fpr);

                status = set_own_key(session, ident, new_key);

            }

            // mistrust fpr from trust

            ident->fpr = fpr_copy;

            ident->comm_type = PEP_ct_mistrusted;

            status = set_trust(session, ident);

            ident->fpr = NULL;

            // Done with old use of ident.

            if (status == PEP_STATUS_OK) {

                // Update fpr for outgoing

                status = myself(session, ident);

            }

            if (status == PEP_STATUS_OK)

                // cascade that mistrust for anyone using this key

                status = mark_as_compromised(session, fpr_copy);

            if (status == PEP_STATUS_OK)

                status = remove_fpr_as_default(session, fpr_copy);

            if (status == PEP_STATUS_OK)

                status = add_mistrusted_key(session, fpr_copy);

            // add to revocation list 

            if (status == PEP_STATUS_OK) 

                status = set_revoked(session, fpr_copy, new_key, time(NULL));            

            // for all active communication partners:

            //      active_send revocation

            if (status == PEP_STATUS_OK)

                status = send_key_reset_to_recents(session, fpr_copy, new_key);

        }

        else { // not is_me

            // remove fpr from all identities

            // remove fpr from all users

            if (status == PEP_STATUS_OK)

                status = remove_fpr_as_default(session, fpr_copy);

            // delete key from DB

            if (status == PEP_STATUS_OK) {};

//                status = delete_keypair(session, fpr_copy);

            // N.B. If this key is being replaced by something else, it

            // is done outside of this function.    

        }

    }

pep_free:

    free(fpr_copy);

    free(own_id);

    free_identity_list(key_idents);

    free_stringlist(keys);

    free(new_key);    

    return status;

}