#!/opt/Lua51/bin/lua

-- Created by jiaqiang.ye@lnxall.com
-- Simple Git Repository Branch-Tag Management
-- 2025/07/28

local cjson      = require "cjson"
local invoker    = require "invoker"
local gfmt       = string.format

-- name of environment variable
local TAGMAN_MAXSIZE   = 0x100000
-- table holding Git repository branch/tag information
local g_repinfo        = {}
local g_pathidx        = {}
-- directory path for `wlos_core
local g_topdir         = invoker.getcwd()
-- configuration Lua script
local g_cfgfile        = nil

local function goodstr(s)
	if type(s) ~= "string" then return false end
	if string.len(s) == 0 then return false end
	return true
end

local function create_tags()
	local repidx, oknum = 0, 0
	local linesep = "===============================================================================\n"

	while true do
		repidx = repidx + 1
		local rinfo, okay = g_repinfo[repidx], nil
		if not rinfo then break end

		-- Goto TOPDIR directory
		if invoker.chdir(g_topdir) ~= 0 then
			io.stderr:write(gfmt("Error, failed to go back to TOPDIR: %s\n", g_topdir))
			io.stderr:flush()
			return false
		end

		-- Then goto git repository
		if invoker.chdir(rinfo.path) ~= 0 then
			io.stderr:write(gfmt("Error, failed to goto directory: %s\n", rinfo.path))
			io.stderr:flush()
			return false
		end

		io.stdout:write(linesep)
		io.stdout:write(linesep)
		io.stdout:flush()
		if rinfo.tag then
			io.stdout:write(gfmt("INFO: checking tag in repository: %s => %s\n", rinfo.path, rinfo.tag))
			io.stdout:flush()
			okay = invoker.invoke(invoker.NOSTDIO, "git", "show", rinfo.tag)
			if okay ~= 0 then
				io.stdout:write(gfmt("INFO: Creating tag in repository: %s => %s\n", rinfo.path, rinfo.tag))
				io.stdout:flush()
				invoker.invoke(0, "git", "fetch", "--all", "--tags")
				okay = invoker.invoke(0, "git", "checkout", rinfo.branch)
				if okay == 0 then okay = invoker.invoke(0, "git", "pull", "--rebase", "origin", rinfo.branch) end
				if okay == 0 then okay = invoker.invoke(0, "git", "tag", rinfo.tag) end
			else
				io.stdout:write(gfmt("INFO: tag already found in repository: %s => %s\n", rinfo.path, rinfo.tag))
				io.stdout:flush()
				-- okay = invoker.invoke(0, "git", "checkout", rinfo.tag)
			end
			if okay == 0 then okay = invoker.invoke(0, "git", "push", "origin", rinfo.tag) end
			if okay ~= 0 then
				io.stderr:write(gfmt("Error, failed to create and push tag in '%s' => %s\n", rinfo.path, rinfo.tag))
				io.stderr:flush()
				return false
			end
		else
			invoker.invoke(0, "git", "fetch", "--all", "--tags")
			okay = invoker.invoke(0, "git", "checkout", rinfo.branch)
			if okay == 0 then okay = invoker.invoke(0, "git", "pull", "--rebase", "origin", rinfo.branch) end
			if okay ~= 0 then
				io.stderr:write(gfmt("Error, failed to checkout branch in '%s' => %s\n", rinfo.path, rinfo.branch))
				io.stderr:flush()
				return false
			end
		end
		oknum = oknum + 1
	end

	return oknum
end

local function tagman_load()
	local cfgd = invoker.readfile(g_cfgfile, TAGMAN_MAXSIZE)
	if not cfgd then
		io.stderr:write(gfmt("Error, failed to read file: %s\n", g_cfgfile))
		io.stderr:flush()
		return false
	end

	local okay, jdat = pcall(cjson.decode, cfgd)
	cfgd = nil -- free memory early
	if not okay or type(jdat) ~= "table" then
		io.stderr:write(gfmt("Error, failed to decode as JSON: %s\n", g_cfgfile))
		io.stderr:flush()
		return false
	end

	local repos = jdat["repolist"]
	if type(repos) ~= "table" then
		io.stderr:write(gfmt("Error, repolist not found in %s\n", g_cfgfile))
		io.stderr:flush()
		return false
	end

	local repidx = 0
	while true do
		repidx = repidx + 1
		local rinfo = repos[repidx]
		if type(rinfo) ~= "table" then break end

		-- extract Git repo information
		local path_g, branch, tagv = rinfo['path'], rinfo['branch'], rinfo['tag']
		if not goodstr(path_g) then
			io.stderr:write(gfmt("Error, invalid git repository information at index: %d\n", repidx))
			io.stderr:flush()
			return false
		end

		local dotgit = gfmt("%s/.git", path_g)
		if invoker.statfile(path_g) ~= "directory" or
			invoker.statfile(dotgit) ~= "directory" then
			io.stderr:write(gfmt("Error, invalid git repository path: %s\n", path_g))
			io.stderr:flush()
			return false
		end

		if g_pathidx[path_g] then -- check for git duplication
			io.stderr:write(gfmt("Error, duplicated git repository: %s\n", path_g))
			io.stderr:flush()
			return false
		end

		if not goodstr(branch) then
			io.stderr:write(gfmt("Error, branch not specified for %s\n", path_g))
			io.stderr:flush()
			return false
		end
		if not goodstr(tagv) then tagv = nil end

		g_pathidx[path_g]  = repidx
		g_repinfo[repidx]   = {
			["path"]       = path_g,
			["branch"]     = branch,
			["tag"]        = tagv,
		}
	end

	return true
end

local function createtag_init(jfile)
	invoker.setenv("FTOPDIR", nil)
	invoker.setenv("LANGUAGE", nil)
	invoker.setenv("LANG", "en_US.UTF-8")

	if not goodstr(g_topdir) then
		io.stderr:write("Error, FTOPDIR not found in environment variable.\n")
		io.stderr:flush()
		return false
	end

	-- determine configuration file
	if not goodstr(jfile) then
		io.stderr:write("Error, JSON file not specified.\n")
		io.stderr:flush()
		return false
	end

	local ftype, fsize = invoker.statfile(jfile)
	if ftype ~= "regular" then
		io.stderr:write(gfmt("Error, tagman config file not found: %s\n", jfile))
		io.stderr:flush()
		return false
	end
	if fsize == 0 or fsize > TAGMAN_MAXSIZE then
		io.stderr:write(gfmt("Error, invalid file size: %s\n", jfile))
		io.stderr:flush()
		return false
	end
	g_cfgfile = jfile
	io.stdout:write(gfmt("INFO: using branch/tag-config file: %s\n", jfile))
	io.stdout:flush()

	-- load the configuration file
	return tagman_load()
end

if not createtag_init(arg[1]) then
	os.exit(1)
end
local numok = create_tags()
if numok then
	io.stdout:write(gfmt("Number of repositories processed: %d\n", numok))
	io.stdout:flush()
	os.exit(0)
end
os.exit(2)