local upload = require "resty.upload"
local uuid = require "resty.jit-uuid"
local cjson = require "cjson"
--# https://github.com/SkyLothar/lua-resty-jwt
--$ opm get SkyLothar/lua-resty-jwt
local jwt = require "resty.jwt"

local chunk_size = 4096
local form = upload:new(chunk_size)
uuid.seed()

local TaskTypes = {
    NOOP = 'NOOP',
    UPLOAD_PICTURE = 'UPLOAD_PICTURE'
}

local task_server = ngx.var.task_server
local htyuc = ngx.var.htyuc
local host = ngx.var.host

ngx.log(ngx.INFO, "TASK_SERVER -> ", task_server)
ngx.log(ngx.INFO, "HTYUC -> ", htyuc)
ngx.log(ngx.INFO, "HOST -> ", host)

local file_dir = ngx.var.tmp_file_dir
local file
local file_name
local files = {}

local http = require "resty.http"
local httpc = http.new()

local function cleanupString(str, remove)
    local lcSubStrTab = {}
    while true do
        local lcPos = string.find(str, remove)
        if not lcPos then
            lcSubStrTab[#lcSubStrTab + 1] = str
            break
        end
        local lcSubStr = string.sub(str, 1, lcPos - 1)
        lcSubStrTab[#lcSubStrTab + 1] = lcSubStr
        str = string.sub(str, lcPos + 1, #str)
    end
    local lcMergeStr = ""
    local lci = 1
    while true do
        if lcSubStrTab[lci] then
            lcMergeStr = lcMergeStr .. lcSubStrTab[lci]
            lci = lci + 1
        else
            break
        end
    end
    return lcMergeStr
end

local function verifyJwtToken(token)
    local http = require "resty.http"
    local httpc = http.new()
    local verify_jwt_url = string.format("%s/api/v1/uc/verify_jwt_token", htyuc)

    ngx.log(ngx.INFO, 'HTYUC VERIFY_JWT_TOKEN_URL -> ' .. verify_jwt_url)

    local res, err = httpc:request_uri(
            verify_jwt_url,
            {
                ssl_verify = false, -- 设置参数 ssl_verify 为false 不校验ssl证书
                method = "POST",
                headers = {
                    ["Host"] = host,
                    ["Authorization"] = token,
                },
            }
    )

    if not res then
        ngx.status = ngx.HTTP_UNAUTHORIZED
        ngx.header.content_type = "application/json; charset=utf-8"
        ngx.log(ngx.ERR, "CAN'T VERIFY JWT TOKEN -> ", err)
        ngx.exit(ngx.HTTP_UNAUTHORIZED)
    else
        if 200 ~= res.status then
            ngx.log(ngx.ERR, "JWT TOKEN VERIFICATION *ERROR* -> ", err)
            ngx.exit(res.status)
        end
    end

    ngx.log(ngx.INFO, "JWT TOKEN VERIFICATION *PASSED*.")

end

local function decodeJwtClaim(jwtClaim)
    local jwtKey = "0xCAFEBABE0xCAFEBABE0xCAFEBABE0xCAFEBABE0xCAFEBABE0xCAFEBABE"
    local jwtObj = jwt:verify(jwtKey, jwtClaim)

    if jwtObj.verified == false then
        ngx.log(ngx.WARN, "INVALID TOKEN -> " .. jwtObj.reason)
        ngx.status = ngx.HTTP_UNAUTHORIZED
        ngx.header.content_type = "application/json; charset=utf-8"
        ngx.say(cjson.encode(jwtObj))
        ngx.exit(ngx.HTTP_UNAUTHORIZED)
    end

    ngx.log(ngx.INFO, "DECODED JWT CLAIM -> " .. cjson.encode(jwtObj))

    local htyToken = cjson.decode(jwtObj.payload.sub)
    ngx.log(ngx.INFO, "DECODED JWT TOKEN -> " .. cjson.encode(htyToken))
    return htyToken
end

local authHeader = ngx.req.get_headers().Authorization
local sudoerToken = ngx.req.get_headers().HtySudoerToken

if authHeader then
   ngx.log(ngx.INFO, 'CHECK_AUTH_HEADER -> ', authHeader)
   local token = decodeJwtClaim(authHeader)
   verifyJwtToken(token)
elseif sudoerToken then
   ngx.log(ngx.INFO, 'CHECK_SUDOER_HEADER -> ', sudoerToken)
   local token = decodeJwtClaim(sudoerToken)
   verifyJwtToken(token)
else
   ngx.log(ngx.ERR, 'NO AUTH/SUDOER HEADERS!')
   ngx.status = 500
   ngx.exit(ngx.HTTP_INTERNAL_SERVER_ERROR)
end

while true do
    local type, res, err = form:read()

    if not type then
        ngx.say("FAILED TO READ *UPLOAD IMAGE* -> ", err)
        return
    end

    if type == "header" then
        --"Content-Disposition","form-data; name=\"files[]\"; filename=\"Song-of-joy.png\""
        --"Content-Type","image\/png"
        local key = res[1]
        local val = res[2]
        if key == "Content-Type" then
            local ext = ngx.re.match(val, [[(\w+)\/(\w+)]], "jo")[2]
            file_name = uuid() .. "." .. ext
        end

        if file_name then
            file = io.open(file_dir .. "/" .. file_name, "w+")
            ngx.log(ngx.INFO, "FILENAME -> ", file_name)
            if not file then
                ngx.say("failed to open file ", file_name)
                return
            end
        end

    elseif type == "body" then
        if file then
            file:write(res)
            -- sha1:update(res)
        end
    elseif type == "part_end" then
        if file then
            file:close()
            table.insert(files, file_name)
        end
        -- 这里要重置一下file_name，否则后面的文件保存时会导致前面已保存的文件变成空文件
        -- file:flush() 和 io.flush() 都没效果
        file_name = nil
        file = nil
    elseif type == "eof" then
        local remote_url = string.format("%s/api/v1/ts/create_task", task_server)
        ngx.log(ngx.INFO, 'remote_url -> ', remote_url)
        ngx.log(ngx.INFO, 'Authorization -> ', authHeader)
        ngx.log(ngx.INFO, 'HtySudoerToken -> ', sudoerToken)

        local body_text = cjson.encode({ task_type = TaskTypes.UPLOAD_PICTURE, data = { images = files } })

        ngx.log(ngx.INFO, 'UPLOAD_PICTURE *body_text* ->', body_text)
        local res, err = httpc:request_uri(
                remote_url,
                {
                    ssl_verify = false, -- 设置参数 ssl_verify 为false 不校验ssl证书
                    method = "POST",
                    headers = {
                        ["Content-Type"] = "application/json",
                        ["Authorization"] = authHeader,
                        ["HtySudoerToken"] = sudoerToken,
                    },
                    body = body_text,
                }
        )
        if res == nil then
            ngx.log(ngx.ERR, "FAILED TO CONNECT TO *TASK_SERVER*", err)
        end

        if 201 ~= res.status then
            ngx.log(ngx.ERR, "TASK CREATE *FAILED*", err)
            ngx.say(err)
            ngx.exit(res.status)
        end
        ngx.say(res.body)
        break
    else
        -- do nothing
    end
end