#include "oauth.h"
#include "http/server/request.h"
#include "http/server/escape.h"

#include "model/client_app.h"
#include "model/account.h"
#include "model/owner.h"

#include "form.h"
#include "json/json.h"
#include "json/layout.h"

#include <stdlib.h>
#include <string.h>
#include <stddef.h>

static bool handle_oauth_authorize( struct http_request* req )
{
	char* client_id = NULL;
	char* redirect_uri = NULL;
	char* response_type = NULL;
	bool result = true;

	struct {
		bool read;
		bool write;
		bool follow;
	} scopes = { false, false, false };

	// Parse query parameters
	{
		const char* key;
		while(( key = http_request_route_query_key(req) )) {
			if( 0 == strcmp(key,"client_id") ) {
				client_id = strdup(http_request_route_query_value(req));
			} else if( 0 == strcmp(key,"redirect_uri") ) {
				redirect_uri = strdup(http_request_route_query_value(req));

				// Validate redirection uri
				bool valid = false;
				if( 0 == strncmp("oauth2redirect://",redirect_uri,17) ) {
					valid = true;
				}

				if( !valid ) {
					result = false; goto cleanup;
				}
			} else if( 0 == strcmp(key,"response_type") ) {
				if( 0 != strcmp(http_request_route_query_value(req),"code") ) {
					result = false; goto cleanup;
				}
			} else if( 0 == strcmp(key,"scope") ) {
				char* scope = strdup(http_request_route_query_value(req));

				char* resume = scope;
				char* item;
				while(( item = strtok_r( NULL, " ", &resume ) )) {
					if( 0 == strcmp(item,"read") ) {
						scopes.read = true;
					} else if( 0 == strcmp(item,"write") ) {
						scopes.write = true;
					} else if( 0 == strcmp(item,"follow") ) {
						scopes.follow = true;
					} else {
						free(scope);
						result = false; goto cleanup;
					}
				}
				free(scope);
			} else {
				printf( "key=%s\n", key );
				printf( "value=%s\n\n", http_request_route_query_value(req) );
			}
		}
	}

	struct client_app* app = client_app_from_id( client_id );
	if( !app) {
		result =false; goto cleanup;
	}

	// Store the redirect URI for later use
	free(app->redirect_uri);
	app->redirect_uri = redirect_uri;
	client_app_save( app );

	http_request_send_headers( req, 200, "text/html", true );
	FILE* f = http_request_get_response_body( req );
	#define RENDER
		#include "view/authorize.html.inc"
	#undef RENDER

	result = true;
cleanup:
	free(client_id);
	free(redirect_uri);
	free(response_type);

	return result;
}

static bool handle_oauth_do_authorize( struct http_request* req )
{
	char* password = NULL;
	char* state = NULL;
	struct owner* o = owner_new();
	struct client_app* app = NULL;

	FILE* body = http_request_get_request_data(req);

	struct form_parser* fp = form_pull_parser_new(body);
	if( !fp ) {
		goto invalid_request;
	}

	char* key;
	while(( key = form_pull_parser_read_key( fp ) )) {
		if( 0 == strcmp(key,"password") ) {
			password = strdup(form_pull_parser_read_value(fp));
		} else if( 0 == strcmp(key,"state") ) {
			state = strdup(form_pull_parser_read_value(fp));
		} else if( 0 == strcmp(key,"id") ) {
			const char* client_id = strdup(form_pull_parser_read_value(fp));
			app = client_app_from_id( client_id );
			if( !app ) { goto invalid_request; }
		}
	}
	form_pull_parser_release(fp);

	if( !app ) { goto invalid_request; }
	if( !password ) { goto invalid_request; }

	if( !owner_check_password( o, password ) ) {
		owner_free(o);
		free(password);

		goto access_denied;
	}

	client_app_gen_auth_code( app );

	char location[512];
	char workspace[1024];
	const char* fmt = ( state ? "%s?code=%s&state=%s" : "%s?code=%s" );
	snprintf( location, 512, fmt, http_escape( app->redirect_uri, workspace, 1024, ":/" ), app->auth_code, state );

	printf( "redirecting to %s\n", location );

	http_request_begin_send_headers( req, 302, false );
	http_request_send_header( req, "Location", location );
	http_request_end_send_headers( req, false );

	free(password);
	return false;
invalid_request:
	printf( "Invalid request\n" );
	http_request_send_headers( req, 400, "text/plain", false );
	fprintf( http_request_get_response_body(req), "invalid_request" );
	return true;
access_denied:
	printf( "Access denied\n" );
	http_request_send_headers( req, 400, "text/plain", false );
	fprintf( http_request_get_response_body(req), "access_denied" );
	return true;
}

static bool handle_oauth_get_token( struct http_request* req )
{
	bool result = true;
	struct account* owner_account = NULL;
	struct owner* owner = NULL;
	struct client_app* app = NULL;
	struct data_t
	{
		char* code;
		char* redirect_uri;
		char* client_secret;
		char* client_id;
		char* grant_type;
		char* username;
		char* password;
	} data;
	memset(&data,0,sizeof(data));

	FILE* post_data = http_request_get_request_data(req);
	const char* content_type = http_request_get_header( req, "Content-Type" );
	if( 0 == strcasecmp(content_type,"application/json") ) {
		#define OBJ_TYPE struct data_t
		static struct json_object_field layout[] = {
			JSON_FIELD_STRING( code, false ),
			JSON_FIELD_STRING( redirect_uri, false ),
			JSON_FIELD_STRING( grant_type, false ),
			JSON_FIELD_STRING( client_secret, false ),
			JSON_FIELD_STRING( client_id, false ),
			JSON_FIELD_STRING( username, false ),
			JSON_FIELD_STRING( password, false ),
			JSON_FIELD_END,
		};
		#undef OBJ_TYPE
		if( !json_read_object_layout_from_FILE( post_data, layout, &data ) ) {
			printf( "A" );
			goto invalid_request;
		}

	} else {

		struct form_parser* fp = form_pull_parser_new(post_data);
		if( !fp ) {
			goto invalid_request;
		}

		char* key;
		// TODO: extend form parser to use a data layout
		while(( key = form_pull_parser_read_key( fp ) )) {
			if( 0 == strcmp(key,"grant_type") ) {
				data.grant_type = strdup(form_pull_parser_read_value(fp));

			} else if( 0 == strcmp(key,"code") ) {
				data.code = strdup(form_pull_parser_read_value(fp));

			} else if( 0 == strcmp(key,"client_id") ) {
				data.client_id = strdup(form_pull_parser_read_value(fp));

			} else if( 0 == strcmp(key,"client_secret") ) {
				data.client_secret = strdup(form_pull_parser_read_value(fp));

			} else if( 0 == strcmp(key,"redirect_uri") ) {
				data.redirect_uri = strdup(form_pull_parser_read_value(fp));

			} else {
				printf( "%s=", key );
				printf( "%s\n", form_pull_parser_read_value(fp) );
			}
		}
		form_pull_parser_release(fp);
	}

	printf( "2" );
	if( !data.redirect_uri ) { goto invalid_request; }
	printf( "3" );
	if( !data.client_id ) { goto invalid_request; }
	printf( "4" );

	app = client_app_from_id( data.client_id );
	if( !app ) { goto invalid_request; }
	printf( "5" );

	if( !app->redirect_uri ) { goto invalid_request; }
	if( 0 != strcmp( app->redirect_uri, data.redirect_uri ) ) { goto invalid_request; }
	printf( "6" );
	if( 0 != strcmp( app->client.secret, data.client_secret ) ) { goto access_denied; }
	if( 0 == strcmp("authorization_code",data.grant_type) ) {
		if( !data.code ) { goto invalid_request; }
		if( 0 != strcmp( app->auth_code, data.code ) ) { goto access_denied; }
	} else if( 0 == strcmp("password", data.grant_type ) ) {
		owner_account = account_from_id(0);
		owner = owner_new();

		if( 0 != strcmp( owner_account->handle, data.username ) ) { goto access_denied; }
		if( !owner_check_password( owner, data.password ) ) { goto access_denied; }
	} else {
		printf( "7" );
		goto invalid_request;
	}

	// TODO: check code has not expired

	client_app_generate_access_token( app );

	http_request_begin_send_headers( req, 200, false );
	http_request_send_header( req, "Content-Type", "application/json" );
	http_request_send_header( req, "Cache-Control", "no-store" );
	http_request_end_send_headers( req, false );

	FILE* f = http_request_get_response_body( req );
	#define RENDER
		#include "view/token_grant.json.inc"
	#undef RENDER

cleanup:
	client_app_free(app);
	free(data.code);
	free(data.redirect_uri);
	free(data.client_secret);
	free(data.client_id);
	free(data.grant_type);
	free(data.password);
	free(data.username);
	owner_free(owner);
	account_free(owner_account);
	return result;

access_denied:
	printf( "Access denied\n" );
	result = false;
	goto cleanup;

invalid_request:
	printf( "Invalid request\n" );
	result = false;
	goto cleanup;

}

bool route_oauth( struct http_request* req )
{
	if( http_request_route( req, "/authorize" ) ) {
		if( http_request_route_method(req,"POST") ) {
			return handle_oauth_do_authorize(req);
		} else if( http_request_route( req, "?" ) ) {
			return handle_oauth_authorize(req);
		}
	} else if( http_request_route( req, "/token" ) ) {
		if( http_request_route_method(req,"POST") ) {
			return handle_oauth_get_token(req);
		}
	}

	return false;
}