resty_functions/scripts/combine.lua

-- 指定模块引用目录，否则无法加载同目录下的其他文件
--package.path = package.path .. ';/usr/local/opt/openresty/nginx/scripts/?.lua';
package.path = package.path .. ';<SCRIPT_PATH>/?.lua';

-- Requires
local uuid = require("lib.my_uuid")
local cjson = require "cjson"
local pl = require "pl.pretty"
local http = require "resty.http"
local verify = require('lib.jwt_verify')
local get_wx_media = require("lib.wx_download")

-- Verify token
local httpc = http:new()
local authHeader = ngx.req.get_headers().Authorization
local sudoerToken = ngx.req.get_headers().HtySudoerToken
verify(httpc, authHeader, sudoerToken)
--uuid.seed()

-- Get ngx var
local file_dir = ngx.var.tmp_file_dir

-- Read request body
ngx.req.read_body()
local req_body = cjson.decode(ngx.req.get_body_data())
ngx.log(ngx.INFO, 'REQ_BODY -> ', ngx.req.get_body_data())

local images = req_body["payload"]["images"]

local image_origin = req_body["payload"]["image_origin"]

-- Judge payload image origin
if image_origin == "WX" then
    ngx.log(ngx.INFO, "IMAGE ORIGIN -> ", image_origin)
elseif image_origin == "LOCAL" then
    ngx.log(ngx.INFO, "IMAGE ORIGIN -> ", image_origin)
else
    image_origin = "LOCAL"
    ngx.log(ngx.INFO, "IMAGE ORIGIN default to LOCAL")
end

-- Judge payload images para length
local len = table.getn(images)
if len == 0 then
    ngx.status = 500
    ngx.log(ngx.ERR, "No images to combine!")
    return ;
end

-- If combine images from WX
local wx_download_images = {}
if image_origin == "WX" then
    for i = 1, len do
        ngx.log(ngx.INFO, "DOWNLOAD WX URL -> ", images[i])
        wx_download_images[i] = get_wx_media(httpc,  images[i], cjson, pl);
    end
end

-- Prepare combined file name and path
local combined_uuid = uuid.uuid()
local output_filename = combined_uuid .. ".jpeg";
local output_filepath = file_dir .. "/" .. output_filename

local origin = {}

-- 从 nginx 变量取
local convert = ngx.var.convert

if not convert then
    ngx.status = 500
    ngx.log(ngx.ERR, "ImageMagick NOT FOUND.")
    return
end

for i = 1, len do

    local incoming

    if image_origin == "WX" then
        ngx.log(ngx.INFO, "DOWNLOAD WX FILE -> ", wx_download_images[i])
        incoming = wx_download_images[i]
    elseif image_origin == "LOCAL" then
        ngx.log(ngx.INFO, "LOCAL FILE -> ", images[i])
        incoming = file_dir .. "/" .. images[i]
    else
        ngx.status = 400
        ngx.log(ngx.ERR, "COMBINE REQUEST PAYLOAD IMAGES ORIGIN NOT FOUND.")
        return
    end

    origin[i] = incoming .. ".png "
    local cmd = convert .. " -resize 642x1389 -strip -quality 75% " .. incoming .. " " .. origin[i]
    ngx.log(ngx.INFO, 'CMD RESIZE -> ', cmd)
    local handle = io.popen(cmd)
    local result = handle:read("*a")
    ngx.log(ngx.INFO, 'CMD RESIZE -> RESULT ', pl.dump(result))
    handle:close()

end

local cmd = convert .. " -append " .. table.concat(origin, " ") .. " " .. output_filepath
ngx.log(ngx.INFO, 'CMD APPEND -> ', cmd)
io.popen(cmd)
ngx.say(output_filename)