#include "inbox.h"

// Submodules
#include "http/server/request.h"
#include "json/json.h"
#include "ffdb/fs_list.h"
#include "collections/array.h"
#include "util/format.h"
#include "ap/object.h"

// Model
#include "model/server.h"
#include "model/status.h"
#include "model/account.h"
#include "model/notification.h"
#include "model/inbox_envelope.h"
#include "model/crypto/http_sign.h"

// Controller
#include "controller/inbox/follow.h"
#include "controller/inbox/forward.h"

// Standard Library
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

extern bool terminate;

// Route: /inbox
bool route_inbox( struct http_request* req )
{
	// No subroutes
	if( !http_request_route_term( req, "" ) ) { return false; }
	if( !http_request_route_method( req, "POST" ) ) { return false; }

	if( envelope_create_from_request( req ) ) {
		http_request_send_headers( req, 200, "text/plain", true );
	} else {
		http_request_send_headers( req, 400, "text/plain", true );
	}

	return true;
}

static bool route_undo_Announce( struct ap_object* act )
{
	struct status* s = NULL;

	s = status_from_uri( act->object.ptr->id );
	if( !s ) { return true; } // Status not local, discard

	printf( "TODO: delete post\n" );

	status_free(s);
	return true;
}
static bool route_undo_Like( struct ap_object* act )
{
	bool result = false;
	struct status* s = NULL;
	struct account* a = NULL;

	s = status_from_uri( act->object.ptr->id );
	if( !s ) { goto discard; } // Satus not local, discard

	a = account_from_uri( act->actor );
	if( !a )

	status_remove_like( s, a );
	goto cleanup;
cleanup:
	status_free(s);
	account_free(a);
	return result;
discard:
	result = true;
	goto cleanup;
}
static bool route_undo_EmojiReact( struct ap_object* act )
{
	bool result = false;
	struct status* s = NULL;
	struct account* a = NULL;
	s = status_from_uri( act->object.ptr->id );
	if( !s ) { goto discard; }

	a = account_from_uri( act->object.ptr->actor );
	if( !a ) { goto discard; }

	status_remove_react( s, act->object.ptr->content.content, a );
	goto discard;
cleanup:
	account_free(a);
	status_free(s);
	return result;
discard:
	result = true;
	goto cleanup;
}

static bool route_undo_activity( struct ap_object* act )
{
	if( act->object.tag != apaot_activity ) {
		printf( "Can't undo reference activities, discarding...\n" );
		return true;
	}
	if( !act->object.ptr ) {
		printf( "No object in activity\n" );
		return false;
	}

	switch( act->object.ptr->type ) {
		case ap_Follow:		return route_undo_follow( act );
		case ap_Announce:		return route_undo_Announce( act );
		case ap_Like:			return route_undo_Like( act );
		case pleroma_EmojiReact:	return route_undo_EmojiReact(act);
		default:
			printf( "Unhandled object activity type %d in undo\n", act->object.ptr->type );
			return false;
	};

	return false;
}

enum {
	error_lookup_failed = 1,
};
static struct status* lookup_object_status( struct ap_object* act, int* error )
{
	struct status* s = NULL;

	switch( act->object.tag ) {
		case apaot_ref:
			s = status_from_uri( act->object.ref );
			if( !s ) {
				s = status_fetch_from_uri( act->object.ref );
				if( !s ) {
					*error = error_lookup_failed;
					return NULL;
				}
				status_save_new(s);
			}
			break;
		case apaot_activity:
			s = status_from_uri( act->object.ptr->id );
			if( !s ) {
				s = status_from_activity( act->object.ptr );
				if( !s ) {
					*error = error_lookup_failed;
					return NULL;
				}
				status_save_new( s );
			}
			break;
	}

	if( s ) { return s; }

	switch( act->object.tag ) {
		case apaot_ref:
			printf( "! Status %s doesn't exist locally (object.ref)\n", act->object.ref );
			break;
		case apaot_activity:
			printf( "! Status %s doesn't exist locally (object.ptr)\n", act->object.ptr->id );
			break;
	}
	return NULL;
}

static struct account* lookup_actor_account( struct ap_object* act )
{
	struct account* a = account_from_uri( act->actor );
	if( a ) { return a; }

	a = account_fetch_from_uri( act->actor );
	return a;
}

static bool route_like( struct ap_object* act )
{
	struct status* s = NULL;
	struct account* liker = NULL;
	bool result = false;
	int error;
	s = lookup_object_status(act,&error);
	liker = lookup_actor_account(act);

	if( !s ) {
		if( error == error_lookup_failed ) { goto discard; }
		goto failed;
	};

	status_add_like( s, liker );
discard:
	result = true;
	goto cleanup;
cleanup:
	account_free(liker);
	status_free(s);
	return result;
failed:
	result = false;
	goto cleanup;
}

static bool route_emoji_react( struct ap_object* act )
{
	struct status* s = NULL;
	struct account* reactor = NULL;
	bool result = false;
	int error;
	s = lookup_object_status(act,&error);
	reactor = lookup_actor_account(act);
	if( !s || !reactor ) { goto failed; }

	status_add_react( s, act->content.content, reactor );
	goto discard;
discard:
	result = true;
	goto cleanup;
cleanup:
	status_free(s);
	account_free(reactor);
	return result;
failed:
	result = false;
	goto cleanup;
}

static bool route_update_Person( struct ap_object* act )
{
	bool result = false;
	struct account* a = account_fetch_from_uri( act->object.ptr->id );
	if( !a ) { return true; } // We don't have this user locally, we can safely discard

	if( !account_sync_from_activity( a, act->object.ptr ) ) { goto failed; }

	account_save(a);

	result = true;
cleanup:
	account_free(a);
	return result;
failed:
	result = false;
	goto cleanup;
}

static bool route_update( struct ap_object* act )
{
	struct status* s = NULL;

	if( act->object.tag == apaot_activity ) {
		switch( act->object.ptr->type ) {
			case ap_Note:
				{
					s = status_from_uri( act->object.ptr->id );
					if( !s ) { return true; } // Status not available locally, discard

					// TODO: update status
				}; break;
			case ap_Person:
				return route_update_Person(act);
			case ap_Question:
				// TODO: update Poll
				return true;
			case ap_Service:
				// discard
				return true;
		}
	} else if( act->object.tag == apaot_ref ) {
		s = status_from_uri( act->object.ref );
		if( !s ) { return true; } // Status not available locally, discard
	}

	status_sync_from_uri( s, s->url );

	status_save(s);
	status_free(s);
	return true;
}

static bool route_move( struct ap_object* act )
{
	bool result = false;
	struct account* a = NULL;

	if( act->object.tag != apaot_ref ) { goto discard; }

	// Make sure this belongs to a local account
	a = account_from_uri( act->object.ref );
	if( !a ) { goto discard; }

	// Verify the target is an existing alias
	for( int i = 0; i < a->aliases.count; ++i ) {
		if( 0 == strcmp( a->aliases.items[i], act->target ) ) {
			goto is_alias;
		}
	}
	goto failed;
is_alias:
	account_move( a, act->target );
	goto discard;
discard:
	result = true;
	goto cleanup;
cleanup:
	account_free(a);
	return result;
failed:
	result = false;
	goto cleanup;
}

static bool route_create( struct ap_object* act )
{
	struct status* s = NULL;
	bool result = false;
	struct account* actor_account = NULL;
	struct account* owner_account = NULL;

	// Requires an object
	if( act->object.tag != apaot_activity ) {
		printf( "TODO: fetch activity from %s\n", act->object.ref );
		goto failed;
	}
	struct ap_object* obj = act->object.ptr;

	bool mentions_me = false;
	bool account_followed = false;

	// Does this activity have mention me
	char owner_url[512];
	snprintf( owner_url, sizeof(owner_url), "https://%s/owner/actor", g_server->domain );
	for( int i = 0; i < obj->tags.count; ++i ) {
		struct ap_activity_tag* tag = obj->tags.items[i];

		//printf( "tag = { &=%p, .type=%d, .href=%s, .name=%s }\n", tag, tag->type, tag->href, tag->name );

		if( tag->type != aptag_mention ) { continue; }
		if( 0 == strcmp(tag->href, owner_url) ) {
			mentions_me = true;
			goto check_is_follower;
		}
	}

check_is_follower:
	// Get actor account
	char* actor_uri = obj->actor;
	if( !actor_uri ) {
		actor_uri = obj->attributed_to;
		obj->actor = strdup(actor_uri);
	}
	actor_account = account_from_uri_or_fetch( actor_uri );
	if( !actor_account ) {
		printf( "! Unable to fetch %s\n", actor_uri );
		goto discard;
	}
	owner_account = account_from_id( owner_account_id );

	if( account_does_follow( owner_account, actor_account->id ) ) {
		account_followed = true;
	}

	if( !account_followed && !mentions_me ) {
		// Discard without action
		//printf( "Discarding create. account_followed=%c, mentions_me=%c\n", account_followed ? 'T' : 'F', mentions_me ? 'T' : 'F' );
		goto discard;
	}

	// Create local status
	s = status_from_uri( obj->id );
	if( !s ) {
		s = status_from_activity(obj);
		if( !s ) {
			printf( "! Failed to load status from activity\n" );
			goto discard;
		}
		status_save_new(s);
	}

	// Add to timelines
	if( account_followed ) {
		status_add_to_timeline( s, home_timeline_id );

		// TODO: create notification if user notifications are on or this is part of a watched conversation
	}
	if( mentions_me ) {
		// Add me to mention lists
		int id = owner_account_id;
		array_append( &s->mentions, sizeof(id), &id );

		// Create notification
		struct notification* note = notification_new();
			note->debug = 6;
			note->type = nt_mention;
			note->status_id = s->id;
			note->account_id = actor_account->id;
		notification_save( note );
		notification_free( note );
	}

	// Add to standard timelines
	status_add_to_timeline( s, public_timeline_id );
	//status_add_to_timeline( s, federated_timeline_id );
	status_add_to_timeline( s, actor_account->id );

discard:
	result = true;
	goto cleanup;
cleanup:
	account_free(actor_account);
	account_free(owner_account);
	status_free(s);
	return result;
failed:
	result = false;
	goto cleanup;
}

static bool route_block( struct ap_object* act )
{
	bool result = false;
	struct account* actor_account = NULL;

	// Get actor account
	actor_account = account_from_uri_or_fetch( act->actor );
	if( !actor_account ) {
		printf( "! Unable to fetch %s\n", act->actor );
		goto failed;
	}

	// TODO: decide what to do about blocks besides feed the block bot

	struct notification* notice = notification_new();
	notice->type = nt_block;
	notice->account_id = system_account_id;
	notice->ref_account_id = actor_account->id;
	notification_save(notice);
	notification_free(notice);

	result = true;
cleanup:
	account_free(actor_account);
	return result;
failed:
	result = false;
	goto cleanup;
}

static bool route_accept( struct ap_object* act )
{
	// TODO: actually handle accepts
	// In particular, this needs to change a follow request to a following accepted
	return true;
}

bool route_activity( struct ap_object* act )
{
	printf( "Handling %s\n", act->id );
	ap_object_write_to_FILE( act, stdout );

	switch( act->type ) {
		case ap_Undo:			return route_undo_activity(act);
		case ap_Follow:		return route_follow(act);
		case ap_Like:			return route_like(act);
		case ap_Create:		return route_create(act);
		case ap_Accept:		return route_accept(act);
		case ap_Announce:		return route_announce(act);
		case ap_Add:			return route_add(act);
		case pleroma_EmojiReact:	return route_emoji_react(act);
		case ap_Update:		return route_update(act);
		case ap_Move:			return route_move(act);
		case ap_Block:			return route_block(act);
		case ap_Remove:		return true;
		default:
			printf( "Unhandled activity type: %d\n", act->type );
	}
	return false;
}

static bool process_one()
{
	// Items requiring cleanup
	struct ap_object* act = NULL;
	struct ap_envelope* env = NULL;
	bool result = false;

	int tail_pos = fs_list_get("data/inbox/TAIL");
	int head_pos = fs_list_get("data/inbox/HEAD");
	if( head_pos <= tail_pos ) { return false; }

	// We have data to process
	printf( "Inbox has %d items pending processing...\n", (head_pos - tail_pos) );

	int id = tail_pos + 1;
	printf( "Next item is #%d\n", id );

	env = ap_envelope_from_id(id);
	bool step_tail = false;

	if( !env ) {
		printf( "! Failed to parse envelope+activity for data/inbox/%d.json\n", id );
		goto discard;
	}

	// Load activity
	FILE* f = fmemopen( env->body, strlen(env->body), "r" );
	act = ap_object_from_FILE(f);
	if( !act ) { goto failed; }

	if( handle_forward( env, act ) ) { goto discard; }

	// Sanitize actor
	if( !act->actor ) {
		if( !act->attributed_to ) {
			printf( "! activity does not have actor or attributedTo property, can't process\n" );
			goto discard;
		}
		act->actor = strdup(act->attributed_to);
	}

	// Discard delete requests
	if( act->type == ap_Delete ) {
		goto discard;
	}

	// Validate signature
	env->validated = http_signature_validate( env, "post /inbox", act->actor );



	if( !env->validated ) { goto discard; }

	printf( "Processing %d\n", id );
	step_tail = route_activity( act );

cleanup:
	printf( "\nstep_tail=%c\n", step_tail ? 'T' : 'F' );
	if( step_tail ) {
		fs_list_set( "data/inbox/TAIL", id );
		result = true;
	}

	ap_object_free(act);
	ap_envelope_free(env);
	printf( "result=%c\n", result ? 'T' : 'F' );
	fflush(stdout);
	return result;
failed:
	result = false;
	goto cleanup;
discard:
	step_tail = true;
	result = true;
	goto cleanup;
}

bool cleanup_box( const char* box )
{
	char tail[512];
	char dead[512];

	int tail_pos = fs_list_get(format(tail,sizeof(tail),"%s/TAIL",box));
	int dead_pos = fs_list_get(format(dead,sizeof(dead),"%s/DEAD",box));
	if( dead_pos < tail_pos ) {
		char filename[512];
		FILE* f = fopen( format(filename,512,"%s/%d.json", box, dead_pos + 1 ), "r" );
		if( f ) {
			fclose(f);
			if( 0 == remove(filename) ) {
				// File successfully remove, advance
				fs_list_set(dead, dead_pos + 1 );

				return true;
			}
		} else {
			// File already doesn't exist, advance
			fs_list_set( dead, dead_pos + 1 );

			return true;
		}
	}
	return false;
}

void process_inbox()
{
	while( !terminate ) {
		bool activity = false;
		activity |= process_one();
		activity |= cleanup_box( "data/inbox" );

		if( !activity ) {
			fflush(stdout);
			sleep(1);
		}
	}
}