added json parser

1 files changed, 113 insertions, 8 deletions

diff --git a/lua/sleep.lua b/lua/sleep.lua
index d84480e..a47f87e 100644
--- a/lua/sleep.lua
+++ b/lua/sleep.lua
@@ -1,13 +1,17 @@
-local timer = {
+local config_file = "../sleep.json" -- TODO: update path to .
+
+local time = {
 	minutes = 25,
 	active = false,
 	format = "%02d:%02d:%02d", -- (HH:MM:SS)
 	remaining = nil,
+
 	prev_state = {
-		timestamp = nil,
+		timestamp = "",
+		remaining = nil,
 		was_active = false,
+		last_update = "", -- ISO 8601
 	},
-	config_file = "sleep.json"
 }
 
 local gesture_state = {
@@ -16,12 +20,113 @@ local gesture_state = {
 	latency = 3, -- seconds
 }
 
-local function reinstate_tstamp()
-	-- call read_config and grab the exported time stamp, then seek to that position in the file
+
+--[[ todo:
+perhaps instead of using a json config_file, we simply write the state attributes at the top of this config_file.
+then have test.lua edit itself as need be.
+]]
+
+--[[
+TODO: merge `read_default_time()` and `read_prev_state`
+      into `read_jsonkey_value(file_str, block_key, value_key)`
+      then have called by `reinstate_prevstate()` to retrieve keys (timestamp, last_updated, etc.)
+      and also wherever read_default_time shoudl be called, will retrieve default_time in config block
+
+	  (parsing logic is the same, so we should reduce the code)
+]]
+
+---------------------------
+--      JSON PARSER      --
+---------------------------
+
+local function read_default_time(file_str)
+	local config_block_i = string.find(file_str, "\"config\"")
+	if not config_block_i then
+		print("\"config\" not found in " .. config_file)
+		return nil
+	end
+
+	local end_config_i = string.find(file_str, "}", config_block_i)
+	if not end_config_i then
+		print("formatting error in " .. config_file)
+		return nil
+	end
+
+	local substr = string.sub(file_str, config_block_i, end_config_i)
+	local def_time = string.match(substr, "\"default_time\"%s*:%s*(%d+)")
+
+	if not def_time then
+		print("could not extract \"default_time\" value in \"config\" key from " .. config_file)
+		return nil
+	end
+
+	return tonumber(def_time)
+end
+
+local function read_prev_state(file_str)
+	-- we want to extract under previous_state:
+	      -- timestamp
+	      -- last_updated
+	      -- was_active
+	      -- last_update
+
+	  local prevstate_block_i = string.find(file_str, "\"previous_state\"")
+	  if not prevstate_block_i then
+		  print("\"previous_state\" block not found in " .. config_file)
+		  return nil
+	  end
+
+	  local end_prevstate_i = string.find(file_str, "}", prevstate_block_i)
+	  if not end_prevstate_i then
+		  print("formatting error in " .. config_file)
+		  return nil
+	  end
+
+	  local substr = string.sub(file_str, prevstate_block_i, end_prevstate_i)
+	  local tstamp = string.match(substr, "\"timestamp\"%s*:%s*\"(.-)\"")
+	  local lastup = string.match(substr, "\"last_updated\"%s*:%s*\"(.-)\"")
+	  local was_active = string.match(substr, "\"was_active\"%s*:%s*([a-zA-Z]+)")
+
+	  if not tstamp then
+		print("could not extract \"timestamp\" value in \"previous_state\" key from " .. config_file)
+		return nil
+	  end
+
+	  if not lastup then
+		print("could not extract \"last_updated\" value in \"previous_state\" key from " .. config_file)
+		return nil
+	  end
+
+	  if not was_active then
+		print("could not extract \"was_active\" value in \"previous_state\" key from " .. config_file)
+		return nil
+	  end
 end
 
 local function read_config()
-	-- if failed, then return mock/default settings defined here
+	print("opening", config_file .. "...")
+
+	local openf = io.input(config_file)
+	if openf == nil then
+		print("failed to open", config_file .. "!")
+		-- TODO: we should make sure it exists, otherwise should create it
+	end
+
+	local file_str = openf:read("*all")
+	if file_str == nil or file_str == "" then
+		print("failed to read config_file into string or config_file is empty")
+	end
+
+	read_default_time(file_str)
+	read_prev_state(file_str)
+
+	print("closing", config_file .. ".")
+	io.close(openf)
+end
+
+local function reinstate_tstamp()
+	-- call read_config and grab the exported time stamp, then seek to that position in the config_file
+	-- config_file is, timer
 end
 
 local function export_time()
@@ -59,10 +164,10 @@ local function handle_gesture()
 		-- should include debouncing logic for clean gesture input (eg. ignore calls made within some tiny time before each other)
 end
 
--- called immediately upon opening a media file
+-- called immediately upon opening a media config_file
 function main()
 	    mp.osd_message("Sleep timer script initialized!", 3)
 end
 
 mp.add_key_binding(nil, "sleep", handle_gesture) -- the user invokes this by gesturing (user-set in input.conf)
-main() -- this is run upon opening a media file
+main() -- this is run upon opening a media config_file