-- luacheck: ignore 212/self

local json = require "util.json";

local sql = require "util.sql";

local xml_parse = require "util.xml".parse;

local uuid = require "util.uuid";

local resolve_relative_path = require "util.paths".resolve_relative_path;

local is_stanza = require"util.stanza".is_stanza;

local t_concat = table.concat;

local noop = function() end

local unpack = table.unpack or unpack;

local function iterator(result)

	return function(result_)

		local row = result_();

		if row ~= nil then

			return unpack(row);

		end

	end, result, nil;

end

local default_params = { driver = "SQLite3" };

local engine;

local function serialize(value)

	local t = type(value);

	if t == "string" or t == "boolean" or t == "number" then

		return t, tostring(value);

	elseif is_stanza(value) then

		return "xml", tostring(value);

	elseif t == "table" then

		local encoded,err = json.encode(value);

		if encoded then return "json", encoded; end

		return nil, err;

	end

	return nil, "Unhandled value type: "..t;

end

local function deserialize(t, value)

	if t == "string" then return value;

	elseif t == "boolean" then

		if value == "true" then return true;

		elseif value == "false" then return false; end

		return nil, "invalid-boolean";

	elseif t == "number" then

		value = tonumber(value);

		if value then return value; end

		return nil, "invalid-number";

	elseif t == "json" then

		return json.decode(value);

	elseif t == "xml" then

		return xml_parse(value);

	end

	return nil, "Unhandled value type: "..t;

end

local host = module.host;

local user, store;

local function keyval_store_get()

	local haveany;

	local result = {};

	local select_sql = [[

	SELECT "key","type","value"

	FROM "prosody"

	WHERE "host"=? AND "user"=? AND "store"=?;

	]]

	for row in engine:select(select_sql, host, user or "", store) do

		haveany = true;

		local k = row[1];

		local v, e = deserialize(row[2], row[3]);

		assert(v ~= nil, e);

		if k and v then

			if k ~= "" then result[k] = v; elseif type(v) == "table" then

				for a,b in pairs(v) do

					result[a] = b;

				end

			end

		end

	end

	if haveany then

		return result;

	end

end

local function keyval_store_set(data)

	local delete_sql = [[

	DELETE FROM "prosody"

	WHERE "host"=? AND "user"=? AND "store"=?

	]];

	engine:delete(delete_sql, host, user or "", store);

	local insert_sql = [[

	INSERT INTO "prosody"

	("host","user","store","key","type","value")

	VALUES (?,?,?,?,?,?);

	]]

	if data and next(data) ~= nil then

		local extradata = {};

		for key, value in pairs(data) do

			if type(key) == "string" and key ~= "" then

				local t, encoded_value = assert(serialize(value));

				engine:insert(insert_sql, host, user or "", store, key, t, encoded_value);

			else

				extradata[key] = value;

			end

		end

		if next(extradata) ~= nil then

			local t, encoded_extradata = assert(serialize(extradata));

			engine:insert(insert_sql, host, user or "", store, "", t, encoded_extradata);

		end

	end

	return true;

end

--- Key/value store API (default store type)

local keyval_store = {};

keyval_store.__index = keyval_store;

function keyval_store:get(username)

	user, store = username, self.store;

	local ok, result = engine:transaction(keyval_store_get);

	if not ok then

		module:log("error", "Unable to read from database %s store for %s: %s", store, username or "<host>", result);

		return nil, result;

	end

	return result;

end

function keyval_store:set(username, data)

	user,store = username,self.store;

	return engine:transaction(function()

		return keyval_store_set(data);

	end);

end

function keyval_store:users()

	local ok, result = engine:transaction(function()

		local select_sql = [[

		SELECT DISTINCT "user"

		FROM "prosody"

		WHERE "host"=? AND "store"=?;

		]];

		return engine:select(select_sql, host, self.store);

	end);

	if not ok then error(result); end

	return iterator(result);

end

--- Archive store API

-- luacheck: ignore 512 431/user 431/store

local map_store = {};

map_store.__index = map_store;

map_store.remove = {};

function map_store:get(username, key)

	local ok, result = engine:transaction(function()

		local query = [[

		SELECT "type", "value"

		FROM "prosody"

		WHERE "host"=? AND "user"=? AND "store"=? AND "key"=?

		LIMIT 1

		]];

		local data, err;

		if type(key) == "string" and key ~= "" then

			for row in engine:select(query, host, username or "", self.store, key) do

				data, err = deserialize(row[1], row[2]);

				assert(data ~= nil, err);

			end

			return data;

		else

			for row in engine:select(query, host, username or "", self.store, "") do

				data, err = deserialize(row[1], row[2]);

				assert(data ~= nil, err);

			end

			return data and data[key] or nil;

		end

	end);

	if not ok then return nil, result; end

	return result;

end

function map_store:set(username, key, data)

	if data == nil then data = self.remove; end

	return self:set_keys(username, { [key] = data });

end

function map_store:set_keys(username, keydatas)

	local ok, result = engine:transaction(function()

		local delete_sql = [[

		DELETE FROM "prosody"

		WHERE "host"=? AND "user"=? AND "store"=? AND "key"=?;

		]];

		local insert_sql = [[

		INSERT INTO "prosody"

		("host","user","store","key","type","value")

		VALUES (?,?,?,?,?,?);

		]];

		local select_extradata_sql = [[

		SELECT "type", "value"

		FROM "prosody"

		WHERE "host"=? AND "user"=? AND "store"=? AND "key"=?

		LIMIT 1;

		]];

		for key, data in pairs(keydatas) do

			if type(key) == "string" and key ~= "" then

				engine:delete(delete_sql,

					host, username or "", self.store, key);

				if data ~= self.remove then

					local t, value = assert(serialize(data));

					engine:insert(insert_sql, host, username or "", self.store, key, t, value);

				end

			else

				local extradata, err = {};

				for row in engine:select(select_extradata_sql, host, username or "", self.store, "") do

					extradata, err = deserialize(row[1], row[2]);

					assert(extradata ~= nil, err);

				end

				engine:delete(delete_sql, host, username or "", self.store, "");

				extradata[key] = data;

				local t, value = assert(serialize(extradata));

				engine:insert(insert_sql, host, username or "", self.store, "", t, value);

			end

		end

		return true;

	end);

	if not ok then return nil, result; end

	return result;

end

local archive_store = {}

archive_store.caps = {

	total = true;

};

archive_store.__index = archive_store

function archive_store:append(username, key, value, when, with)

	local user,store = username,self.store;

	when = when or os.time();

	with = with or "";

	local ok, ret = engine:transaction(function()

		local delete_sql = [[

		DELETE FROM "prosodyarchive"

		WHERE "host"=? AND "user"=? AND "store"=? AND "key"=?;

		]];

		local insert_sql = [[

		INSERT INTO "prosodyarchive"

		("host", "user", "store", "when", "with", "key", "type", "value")

		VALUES (?,?,?,?,?,?,?,?);

		]];

		if key then

			engine:delete(delete_sql, host, user or "", store, key);

		else

			key = uuid.generate();

		end

		local t, encoded_value = assert(serialize(value));

		engine:insert(insert_sql, host, user or "", store, when, with, key, t, encoded_value);

		return key;

	end);

	if not ok then return ok, ret; end

	return ret; -- the key

end

-- Helpers for building the WHERE clause

local function archive_where(query, args, where)

	-- Time range, inclusive

	if query.start then

		args[#args+1] = query.start

		where[#where+1] = "\"when\" >= ?"

	end

	if query["end"] then

		args[#args+1] = query["end"];

		if query.start then

			where[#where] = "\"when\" BETWEEN ? AND ?" -- is this inclusive?

		else

			where[#where+1] = "\"when\" <= ?"

		end

	end

	-- Related name

	if query.with then

		where[#where+1] = "\"with\" = ?";

		args[#args+1] = query.with

	end

	-- Unique id

	if query.key then

		where[#where+1] = "\"key\" = ?";

		args[#args+1] = query.key

	end

end

local function archive_where_id_range(query, args, where)

	local args_len = #args

	-- Before or after specific item, exclusive

	if query.after then  -- keys better be unique!

		where[#where+1] = [[

		"sort_id" > COALESCE(

			(

				SELECT "sort_id"

				FROM "prosodyarchive"

				WHERE "key" = ? AND "host" = ? AND "user" = ? AND "store" = ?

				LIMIT 1

			), 0)

		]];

		args[args_len+1], args[args_len+2], args[args_len+3], args[args_len+4] = query.after, args[1], args[2], args[3];

		args_len = args_len + 4

	end

	if query.before then

		where[#where+1] = [[

		"sort_id" < COALESCE(

			(

				SELECT "sort_id"

				FROM "prosodyarchive"

				WHERE "key" = ? AND "host" = ? AND "user" = ? AND "store" = ?

				LIMIT 1

			),

			(

				SELECT MAX("sort_id")+1

				FROM "prosodyarchive"

			)

		)

		]]

		args[args_len+1], args[args_len+2], args[args_len+3], args[args_len+4] = query.before, args[1], args[2], args[3];

	end

end

function archive_store:find(username, query)

	query = query or {};

	local user,store = username,self.store;

	local total;

	local ok, result = engine:transaction(function()

		local sql_query = [[

		SELECT "key", "type", "value", "when", "with"

		FROM "prosodyarchive"

		WHERE %s

		ORDER BY "sort_id" %s%s;

		]];

		local args = { host, user or "", store, };

		local where = { "\"host\" = ?", "\"user\" = ?", "\"store\" = ?", };

		archive_where(query, args, where);

		-- Total matching

		if query.total then

			local stats = engine:select("SELECT COUNT(*) FROM \"prosodyarchive\" WHERE "

				.. t_concat(where, " AND "), unpack(args));

			if stats then

				for row in stats do

					total = row[1];

				end

			end

			if query.limit == 0 then -- Skip the real query

				return noop, total;

			end

		end

		archive_where_id_range(query, args, where);

		if query.limit then

			args[#args+1] = query.limit;

		end

		sql_query = sql_query:format(t_concat(where, " AND "), query.reverse

			and "DESC" or "ASC", query.limit and " LIMIT ?" or "");

		return engine:select(sql_query, unpack(args));

	end);

	if not ok then return ok, result end

	return function()