#!/opt/lnxall_app/bin/lua

local invoker = require "invoker"
local hal = require "lnxhal"
local module = {}

local LOG_DIR = "/var/log/compressed"
local LOG_MAX_AGE = 14 * 24 * 60 * 60
local SSD_FULL_PERCENT = 92

function module.checkplat()
	local cpuinfo = hal.cpuinfo_get()
	return type(cpuinfo) == "table" and cpuinfo.arch == hal.ARCH_AARCH64
end

function module.category()
	return "存储媒介"
end

function module.description()
	return "检查固态硬盘"
end

function module.detailed()
	return "检查 nvme0n1 设备、挂载和空间，并扫描近期内核日志中的介质错误。"
end

function module.suggestion()
	return table.concat({
		"1. ls /dev/nvme0n1 : 如果输出为空且断电重启后恢复，可能是已知 SSD 主控问题。",
		"2. 如果 /dev/nvme0n1 存在但 df -h 查不到 /mnt/ssd，请检查挂载。",
		"3. nvme smart-log /dev/nvme0n1 查看健康信息。",
		"4. dmesg | grep -i -E 'ext4|critical medium error'.",
	}, "\n")
end

local function shell_quote(value)
	return "'" .. string.gsub(value, "'", "'\\''") .. "'"
end

local function is_buster()
	local release = invoker.readfile("/etc/os-release")
	return type(release) == "string" and
		string.find(release, "Debian", 1, true) ~= nil and
		string.find(release, "buster", 1, true) ~= nil
end

local function get_usage()
	local _, output = invoker.invoke(invoker.OUTPUT, "df", "-h")
	if type(output) ~= "string" then
		return -1, nil, false
	end

	local percent = -1
	local usage_line
	for line in string.gmatch(output, "[^\r\n]+") do
		if string.find(line, "nvme0n1", 1, true) then
			local value = tonumber(string.match(line, "(%d+)%%"))
			if value then
				percent = value
			end
			usage_line = line
		end
	end

	return percent, usage_line, percent >= SSD_FULL_PERCENT
end

local function has_recent_storage_error()
	local logs = invoker.glob(LOG_DIR .. "/kern*.gz")
	if not logs then
		return false, "not found"
	end

	local now = os.time()
	for _, logfile in ipairs(logs) do
		local ftype, _, _, _, mtime = invoker.statfile(logfile)
		if ftype == "regular" and type(mtime) == "number" and
			now - mtime <= LOG_MAX_AGE then
			local command = "gzip -d -c " .. shell_quote(logfile) ..
				" | grep -e 'critical medium error' -e 'EXT4-fs error'"
			local status, output = invoker.invoke(invoker.OUTPUT, "sh", "-c", command)
			if status == 0 and type(output) == "string" and #output > 0 then
				return true
			end
		end
	end

	return false
end

function module.step()
	local not_mounted = is_buster() and not invoker.mountpoint("/mnt/ssd")
	local no_nvme0n1
	if not invoker.statfile("/dev/nvme0n1") then
		no_nvme0n1 = "SSD 主控可能存在问题，断电重启可恢复"
	end

	local has_nvme0n2 = invoker.statfile("/dev/nvme0n2") ~= nil
	local usage_percent, usage, almost_full = get_usage()
	local result = {
		["not mounted"] = not_mounted,
		["no nvme0n1"] = no_nvme0n1,
		["has nvme0n2"] = has_nvme0n2,
		["almost full"] = almost_full,
		["usage percent"] = usage_percent,
		usage = usage,
	}

	if not_mounted or no_nvme0n1 or has_nvme0n2 or almost_full then
		return result, true
	end

	local has_log_error, log_status = has_recent_storage_error()
	if log_status then
		result["kernel logs"] = log_status
	end
	if has_log_error then
		result["EXT4 ERROR"] = true
		return result, true
	end

	return result, false
end

return module