local hex = require "util.hex";

local random = require "util.random";

local url = require "socket.url";

local datetime = require "util.datetime".datetime;

local http = require 'net.http'

local json = require "util.json";

local errors = require "util.error";

local promise = require "util.promise";

local unpack = unpack or table.unpack -- luacheck: ignore

local user_agent = ("prosody-mod-%s/%s"):format((module.name:gsub("%W", "-")), (prosody.version:gsub("[^%w.-]", "-")));

local function generate_event_id()

	return hex.to(random.bytes(16));

end

local function get_endpoint(server, name)

	return ("%s/api/%d/%s/"):format(server.base_uri, server.project_id, name);

end

-- Parse a DSN string

-- https://develop.sentry.dev/sdk/overview/#parsing-the-dsn

local function parse_dsn(dsn_string)

	local parsed = url.parse(dsn_string);

	if not parsed then

		return nil, "unable to parse dsn (url)";

	end

	local path, project_id = parsed.path:match("^(.*)/(%d+)$");

	if not path then

		return nil, "unable to parse dsn (path)";

	end

	local base_uri = url.build({

		scheme = parsed.scheme;

		host = parsed.host;

		port = parsed.port;

		path = path;

	});

	return {

		base_uri = base_uri;

		public_key = parsed.user;

		project_id = project_id;

	};

end

local function get_error_data(instance_id, context)

	local data = {

		instance_id = instance_id;

	};

	for k, v in pairs(context) do

	end

	return data;

end

local function error_to_sentry_exception(e)

	local exception = {

		type = e.condition or (e.code and tostring(e.code)) or nil;

		value = e.text or tostring(e);

		context = e.source;

		mechanism = {

			type = "generic";

			description = "Prosody error object";

			synthetic = not not e.context.wrapped_error;

			data = get_error_data(e.instance_id, e.context);

		};

	};

	local traceback = e.context.traceback;

	if traceback and type(traceback) == "table" then

		local frames = {};

		for i = #traceback, 1 do

			local frame = traceback[i];

			table.insert(frames, {

				["function"] = frame.info.name;

				filename = frame.info.short_src;

				lineno = frame.info.currentline;

			});

		end

		exception.stacktrace = {

			frames = frames;

		};

	end

	return exception;

end

local sentry_event_methods = {};

local sentry_event_mt = { __index = sentry_event_methods };

function sentry_event_methods:set(key, value)

	self.event[key] = value;

	return self;

end

function sentry_event_methods:tag(tag_name, tag_value)

	local tags = self.event.tags;

	if not tags then

		tags = {};

		self.event.tags = tags;

	end

	if type(tag_name) == "string" then

		tags[tag_name] = tag_value;

	else

		for k, v in pairs(tag_name) do

			tags[k] = v;

		end

	end

	return self;

end

function sentry_event_methods:extra(key, value)

	local extra = self.event.extra;

	if not extra then

		extra = {};

		self.event.extra = extra;

	end

	if type(key) == "string" then

		extra[key] = tostring(value);

	else

		for k, v in pairs(key) do

			extra[k] = tostring(v);

		end

	end

	return self;

end

function sentry_event_methods:message(text)

	return self:set("message", { formatted = text });

end

function sentry_event_methods:add_exception(e)

	if errors.is_err(e) then

		e = error_to_sentry_exception(e);

	elseif type(e) ~= "table" or not (e.type and e.value) then

		e = error_to_sentry_exception(errors.coerce(nil, e));

	end

	local exception = self.event.exception;

	if not exception or not exception.values then

		exception = { values = {} };

		self.event.exception = exception;

	end

	table.insert(exception.values, e);

	return self;

end

function sentry_event_methods:add_breadcrumb(crumb_timestamp, crumb_type, crumb_category, message, data)

	local crumbs = self.event.breadcrumbs;

	if not crumbs then

		crumbs = { values = {} };

		self.event.breadcrumbs = crumbs;

	end

	local crumb = {

		timestamp = crumb_timestamp and datetime(crumb_timestamp) or self.timestamp;

		type = crumb_type;

		category = crumb_category;

		message = message;

		data = data;

	};

	table.insert(crumbs.values, crumb);

	return self;

end

function sentry_event_methods:add_http_request_breadcrumb(http_request, message)

	local request_id_message = ("[Request %s]"):format(http_request.id);

	message = message and (request_id_message.." "..message) or request_id_message;

	return self:add_breadcrumb(http_request.time, "http", "net.http", message, {

		url = http_request.url;

		method = http_request.method or "GET";

		status_code = http_request.response and http_request.response.code or nil;

	});

end

function sentry_event_methods:set_request(http_request)

	return self:set("request", {

		method = http_request.method;

		url = url.build(http_request.url);

		headers = http_request.headers;

		env = {

			REMOTE_ADDR = http_request.ip;

		};

	});

end

function sentry_event_methods:send()

	return self.server:send(self.event);

end

local sentry_mt = { }

sentry_mt.__index = sentry_mt

local function new(conf)

	local server = assert(parse_dsn(conf.dsn));

	return setmetatable({

		server = server;

		endpoints = {

			store = get_endpoint(server, "store");

		};

		insecure = conf.insecure;

		tags = conf.tags or nil,

		extra = conf.extra or nil,

		server_name = conf.server_name or "undefined";

		logger = conf.logger;

	}, sentry_mt);

end

local function resolve_sentry_response(response)

	if response.code == 200 and response.body then

		local data = json.decode(response.body);

		return data;

	end

	return promise.reject(response);

end

function sentry_mt:send(event)

	local json_payload = json.encode(event);

	local response_promise, err = self:_request(self.endpoints.store, "application/json", json_payload);

	if not response_promise then

		module:log("warn", "Failed to submit to Sentry: %s %s", err, json);

		return nil, err;

	end

	return response_promise:next(resolve_sentry_response), event.event_id;

end

function sentry_mt:_request(endpoint_url, body_type, body)

	local auth_header = ("Sentry sentry_version=7, sentry_client=%s, sentry_timestamp=%s, sentry_key=%s")

		:format(user_agent, datetime(), self.server.public_key);

	return http.request(endpoint_url, {

		headers = {

			["X-Sentry-Auth"] = auth_header;

			["Content-Type"] = body_type;

			["User-Agent"] = user_agent;

		};

		insecure = self.insecure;

		body = body;

	});

end

function sentry_mt:event(level, source)

	local event = setmetatable({

		server = self;

		event = {

			event_id = generate_event_id();

			timestamp = datetime();

			platform = "lua";

			server_name = self.server_name;

			logger = source or self.logger;

			level = level;

		};

	}, sentry_event_mt);

	if self.tags then

		event:tag(self.tags);

	end

	if self.extra then

		event:extra(self.extra);

	end

	return event;

end

return {

	new = new;

};