redis_runner.lua

---
--- Created Created by Swav Swiac on 23/07/2015.
---
--- Allows to run Redis Lua script in a debuggable environment resembling one provided by Redis
---
--- Usage:
---
--- local runner = require 'redis_runner'.connect(host, port)
---
--- local KEYS = {}
--- local ARGV = {}
--- local result = runner.runDebug('my_func.lua', KEYS, ARGV)
--- runner.dump(result)
---

-- default redis connection details
local default_host = "127.0.0.1"
local default_port = 6379

local P = {}
setmetatable(P, { __index = _G })
setfenv(1, P)

-- libs included in Redis
local table = require 'table'
local string = require 'string'
local math = require 'math'
local debug = require 'debug'
local struct = require 'struct'
local cjson = require 'cjson'
local cmsgpack = require 'cmsgpack'
local bit = require 'bit'
--local sha1hex = require 'redis.sha1hex'

local redis = require 'redis'

local run = function(debug, client, scriptfile, KEYS, ARGV)

	-- Simulate Redis Lua environment by adding globals and functions
	local globals = {
		KEYS = KEYS,
		ARGV = ARGV,
		table = table,
		string = string,
		math = math,
		debug = debug,
		struct = struct,
		cjson = cjson,
		cmsgpack = cmsgpack,
		bit = bit
	}

	globals.client = client

	-- add lua-cjson and lua-cmsgpack
	globals.cjson = cjson
	globals.cmsgpack = cmsgpack

	globals.redis = {
		LOG_DEBUG = 'DEBUG',
		LOG_VERBOSE = 'VERBOSE',
		LOG_NOTICE = 'NOTICE',
		LOG_WARNING = 'WARNING'
	}

	-- add redis.call
	globals.redis.call = function(cmd, ...)

		if debug then print(cmd .. ' ' .. ...) end

		-- fetch correct command from redis-lua library
		local command = client[string.lower(cmd)]
		assert(command, 'Unknown command ' .. cmd)

		-- execute it, first argument must be client object to simulate "client:" call
		local result = command(client, ...)

		-- convert result back to Redis style of {k1, v1, k2, v2 ...} if necessary
		if type(result) == 'table' then
			local fixed_result = {}
			local i = 1;
			for k, v in pairs(result) do
				if type(k) ~= 'number' then
					fixed_result[i] = k
					fixed_result[i + 1] = v
					i = i + 2
				else
					fixed_result[i] = v
					i = i + 1
				end
			end
			result = fixed_result
		end
		return result
	end

	-- add redis.log
	globals.redis.log = function(level, message)
		print('[' .. level .. '] ' .. message)
	end

	local env = setmetatable(globals, { __index = _G })
	local err, result = assert(pcall(setfenv(assert(loadfile(scriptfile)), env)))
	setmetatable(env, nil)
	return result
end

-- prints dump of given variable
local dump = function(var)
	if type(var) == 'table' then
		require 'pl.pretty'.dump(var)
	elseif type(var) == 'string' then
		print('"' .. var .. '"')
	else
		print(tostring(var))
	end
end

-- connect to Redis
function connect(host, port)

	host = host or default_host
	port = port or default_port
	local client = redis.connect(host, port)

	return {
		-- run script without debug info
		run = function(scriptfile, KEYS, ARGV)
			return run(false, client, scriptfile, KEYS, ARGV)
		end,

		-- run script with extra debug info
		runDebug = function(scriptfile, KEYS, ARGV)
			return run(true, client, scriptfile, KEYS, ARGV)
		end,
		dump = dump
	}
end

return P