--[[

DB Tables:

	Prosody - key-value, map

		| host | user | store | key | type | value |

	ProsodyArchive - list

		| host | user | store | key | time | stanzatype | jsonvalue |

Mapping:

	Roster - Prosody

		| host | user | "roster" | "contactjid" | type | value |

		| host | user | "roster" | NULL | "json" | roster[false] data |

	Account - Prosody

		| host | user | "accounts" | "username" | type | value |

	Offline - ProsodyArchive

		| host | user | "offline" | "contactjid" | time | "message" | json|XML |

]]

local type = type;

local tostring = tostring;

local tonumber = tonumber;

local pairs = pairs;

local next = next;

local setmetatable = setmetatable;

local xpcall = xpcall;

local json = require "util.json";

local connection;

local host,user,store = module.host;

local params = module:get_option("sql");

local resolve_relative_path = require "core.configmanager".resolve_relative_path;

do -- process options to get a db connection

	params = params or { driver = "SQLite3" };

	if params.driver == "SQLite3" then

		params.database = resolve_relative_path(prosody.paths.data or ".", params.database or "prosody.sqlite");

	end

	assert(params.driver and params.database, "Both the SQL driver and the database need to be specified");

	-- Automatically create table, ignore failure (table probably already exists)

	local create_sql = "CREATE TABLE `prosody` (`host` TEXT, `user` TEXT, `store` TEXT, `key` TEXT, `type` TEXT, `value` TEXT);";

	if params.driver == "PostgreSQL" then

		create_sql = create_sql:gsub("`", "\"");

	end

	local stmt = connection:prepare(create_sql);

	if stmt then

		local ok = stmt:execute();

		local commit_ok = connection:commit();

		if ok and commit_ok then

			module:log("info", "Initialized new %s database with prosody table", params.driver);

		end

	end

end

local function serialize(value)

	local t = type(value);

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

		return t, tostring(value);

	elseif t == "table" then

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

		if value then return "json", value; 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

	elseif t == "number" then return tonumber(value);

	elseif t == "json" then

		return json.decode(value);

	end

end

local function getsql(sql, ...)

	if params.driver == "PostgreSQL" then

		sql = sql:gsub("`", "\"");

	end

	-- do prepared statement stuff

	local stmt, err = connection:prepare(sql);

	if not stmt then module:log("error", "QUERY FAILED: %s %s", err, debug.traceback()); return nil, err; end

	-- run query

	local ok, err = stmt:execute(host or "", user or "", store or "", ...);

	if not ok then return nil, err; end

	return stmt;

end

local function setsql(sql, ...)

	local stmt, err = getsql(sql, ...);

	if not stmt then return stmt, err; end

	return stmt:affected();

end

local function transact(...)

	-- ...

end

local function rollback(...)

	return ...;

end

local function commit(...)

	if not connection:commit() then return nil, "SQL commit failed"; end

	return ...;

end

local function keyval_store_get()

	local stmt, err = getsql("SELECT * FROM `prosody` WHERE `host`=? AND `user`=? AND `store`=?");

	local haveany;

	local result = {};

	for row in stmt:rows(true) do

		haveany = true;

		local k = row.key;

		local v = deserialize(row.type, row.value);

		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

	return commit(haveany and result or nil);

end

local function keyval_store_set(data)

	local affected, err = setsql("DELETE FROM `prosody` WHERE `host`=? AND `user`=? AND `store`=?");

	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, value = serialize(value);

				if not t then return rollback(t, value); end

				local ok, err = setsql("INSERT INTO `prosody` (`host`,`user`,`store`,`key`,`type`,`value`) VALUES (?,?,?,?,?,?)", key, t, value);

				if not ok then return rollback(ok, err); end

			else

				extradata[key] = value;

			end

		end

		if next(extradata) ~= nil then

			local t, extradata = serialize(extradata);

			if not t then return rollback(t, extradata); end

			local ok, err = setsql("INSERT INTO `prosody` (`host`,`user`,`store`,`key`,`type`,`value`) VALUES (?,?,?,?,?,?)", "", t, extradata);

			if not ok then return rollback(ok, err); end

		end

	end

	return commit(true);

end

local keyval_store = {};

keyval_store.__index = keyval_store;

function keyval_store:get(username)

	user,store = username,self.store;

	local success, ret, err = xpcall(keyval_store_get, debug.traceback);

	if success then return ret, err; else return rollback(nil, ret); end

end

function keyval_store:set(username, data)

	user,store = username,self.store;

	local success, ret, err = xpcall(function() return keyval_store_set(data); end, debug.traceback);

	if success then return ret, err; else return rollback(nil, ret); end

end

local function map_store_get(key)

	local stmt, err = getsql("SELECT * FROM `prosody` WHERE `host`=? AND `user`=? AND `store`=? AND `key`=?", key or "");

	local haveany;

	local result = {};

	for row in stmt:rows(true) do

		haveany = true;

		local k = row.key;

		local v = deserialize(row.type, row.value);

		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

	return commit(haveany and result[key] or nil);

end

local function map_store_set(key, data)

	local affected, err = setsql("DELETE FROM `prosody` WHERE `host`=? AND `user`=? AND `store`=? AND `key`=?", key or "");

	if data and next(data) ~= nil then

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

			local t, value = serialize(data);

			if not t then return rollback(t, value); end

			local ok, err = setsql("INSERT INTO `prosody` (`host`,`user`,`store`,`key`,`type`,`value`) VALUES (?,?,?,?,?,?)", key, t, value);

			if not ok then return rollback(ok, err); end

		else

			-- TODO non-string keys

		end

	end

	return commit(true);

end

local map_store = {};

map_store.__index = map_store;

function map_store:get(username, key)

	user,store = username,self.store;

	local success, ret, err = xpcall(function() return map_store_get(key); end, debug.traceback);

	if success then return ret, err; else return rollback(nil, ret); end

end

function map_store:set(username, key, data)

	user,store = username,self.store;

	local success, ret, err = xpcall(function() return map_store_set(key, data); end, debug.traceback);

	if success then return ret, err; else return rollback(nil, ret); end

end

local list_store = {};

list_store.__index = list_store;

function list_store:scan(username, from, to, jid, typ)

	user,store = username,self.store;

	local cols = {"from", "to", "jid", "typ"};

	local vals = { from ,  to ,  jid ,  typ };

	local stmt, err;

	local query = "SELECT * FROM `prosodyarchive` WHERE `host`=? AND `user`=? AND `store`=?";

	query = query.." ORDER BY time";

	--local stmt, err = getsql("SELECT * FROM `prosody` WHERE `host`=? AND `user`=? AND `store`=? AND `key`=?", key or "");

	return nil, "not-implemented"

end

local driver = { name = "sql" };

function driver:open(store, typ)

	if not typ then -- default key-value store

		return setmetatable({ store = store }, keyval_store);

	end

	return nil, "unsupported-store";

end

module:add_item("data-driver", driver);