require("app.app")
local http = require("socket.http")
local ltn12 = require("ltn12")
local httpclient = require("fwutils.httpclient")
local cache = require("fwutils.cache")


local M = {}

-- access_token 的 url
M.url_get_access_token = "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential"

-- 获取用户access_token的url
M.url_get_user_access_token = "https://api.weixin.qq.com/sns/oauth2/access_token?grant_type=authorization_code"

-- 获取用户信息的url
M.url_get_user_info = "https://api.weixin.qq.com/sns/userinfo?lang=zh_CN"
-- 授权地址
M.url_auth = "https://open.weixin.qq.com/connect/oauth2/authorize"
-- 模板消息
M.url_template_message = "https://api.weixin.qq.com/cgi-bin/message/template/send"
-- 获取 access_token
M.get_access_token = function(appid, appsecret)
    -- local value = cache.get_json("wxofficial_info")
    -- if value then 
    --     -- 是否距离过期至少还有5分钟
    --     if value.expires_seconds > os.time() + 300 then
    --         return true, value.access_token
    --     end
    -- end

    -- 如果 appid 和 appsecret 为空，则返回 nil
    if appid == nil or appid == "" then 
        return false, "appid 为空"
    end
    if appsecret == nil or appsecret == "" then
        return false, "appsecret 为空"
    end



    -- 先检查有没有过期
    local cache_data = cache.get_json(tostring("wxofficial_info_"..appid))
    if cache_data then
        if cache_data.update_time and cache_data.access_token then
            -- 检查是否过期
            if os.time() - cache_data.update_time < 7200 then
                return true,cache_data.access_token
            end
        end
    end



    local result, data = httpclient.get(M.url_get_access_token .. "&appid=" .. appid .. "&secret=" .. appsecret)
    if not result then
        return false, data
    end

    local body = cjson.decode(data)
    if body.errcode ~= nil and body.errcode ~= 0 then
        return false, body.errmsg
    end

 
    -- 更新
    cache.set_json(tostring("wxofficial_info_"..appid),{
        update_time = os.time(),
        access_token = body.access_token
    })
    return true,body.access_token


end

-- 获取用户access_token
M.get_user_access_token = function(appid, appsecret, code)
    local result, data = httpclient.get(M.url_get_user_access_token .. "&appid=" .. appid .. "&secret=" .. appsecret .. "&code=" .. code)
    if not result then
        return false, data
    end

    local body = cjson.decode(data)
    if body.errcode ~= nil and body.errcode ~= 0 then
        return false, body.errmsg
    end
    return true, body
end

-- 获取用户信息
M.get_user_info = function(access_token, openid)
    local url = M.url_get_user_info .. "&access_token=" .. access_token .. "&openid=" .. openid
    local result, data = httpclient.get(url)
    if not result then
        return false, data
    end

    local body = cjson.decode(data)
    if body.errcode ~= nil and body.errcode ~= 0 then
        return false, body.errmsg
    end
    return true, body
end

-- 生成授权地址
M.generate_auth_url = function(appid, redirect_uri)
    return M.url_auth .. "?appid=" .. appid .. "&redirect_uri=" .. redirect_uri .. "&response_type=code&scope=snsapi_userinfo&state=1#wechat_redirect"
end

-- 发送模板消息
M.send_template_message = function(appid, appsecret, openid, template_id, jump_url, data)
    local ok, access_token = M.get_access_token(appid, appsecret)
    if not ok then
        return false, access_token
    end
    local url = M.url_template_message .. "?access_token=" .. access_token

    local body = {
        touser = openid, 
        template_id = template_id,
        url = jump_url,
        data = data,
        appid = appid
    }
    local result, response = httpclient.post(url, {
        ["Content-Type"] = "application/json"
    }, cjson.encode(body))
    
    if not result then
        return false, response
    end
    local res_json = cjson.decode(response)
    if res_json.errcode ~= 0 then
        return false, res_json.errmsg
    end
    return true
end


-- 生成一次性订阅确认地址
M.generate_subscribe_confirm_url = function(appid, scene, template_id, redirect_uri, reserved)
    return "https://mp.weixin.qq.com/mp/subscribemsg?action=get_confirm&appid=" .. appid .. "&scene=" .. scene .. "&template_id=" .. template_id .. "&redirect_url=" .. redirect_uri .. "&#wechat_redirect"
end

--------------------------------------------------------------------------------
-- 以下为新增的部分，用于微信JS SDK 配置

-- 生成随机字符串函数
local function generate_nonce_str(length)
    --math.randomseed(os.time() + math.random())  -- 增加随机种子
    local chars = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789'
    local res = {}
    for i = 1, (length or 16) do
        local rand = math.random(1, #chars)
        res[#res+1] = string.sub(chars, rand, rand)
    end
    return table.concat(res)
end

-- 获取 jsapi_ticket
M.get_jsapi_ticket = function(appid, appsecret)
    local ticket_info = cache.get_json("wxjsapi_ticket")
    if ticket_info then
        if ticket_info.expires > os.time() + 300 then
            return true, ticket_info.ticket
        end
    end

    local ok, access_token = M.get_access_token(appid, appsecret)
    if not ok then
        return false, access_token
    end

    local ticket_url = "https://api.weixin.qq.com/cgi-bin/ticket/getticket?access_token=" .. access_token .. "&type=jsapi"
    local result, data = httpclient.get(ticket_url)
    if not result then
        return false, data
    end

    local body = cjson.decode(data)
    if body.errcode ~= 0 then
        return false, body.errmsg
    end

    cache.set_json("wxjsapi_ticket", {
        ticket = body.ticket,
        expires = os.time() + body.expires_in
    })
    return true, body.ticket
end

-- 获取微信JS SDK所需的配置参数
-- 参数 current_url 必须是当前网页的完整 URL（不包含#号后的部分）
M.get_js_sdk_config = function(appid, appsecret, current_url)
    local ok, jsapi_ticket = M.get_jsapi_ticket(appid, appsecret)
    if not ok then
        return false, jsapi_ticket..",err"
    end

    local nonceStr = generate_nonce_str(16)
    local timestamp = os.time()

    -- 拼接待签名字符串，注意顺序及格式严格按照微信要求
    local str = "jsapi_ticket=" .. jsapi_ticket .. "&noncestr=" .. nonceStr .. "&timestamp=" .. timestamp .. "&url=" .. current_url
    -- 计算 SHA1 签名（需在 OpenResty 下使用 ngx.sha1_bin 和 resty.string.to_hex）
    local signature = codec.sha1(str)

    return true, {
        appId = appid,
        timestamp = timestamp,
        nonceStr = nonceStr,
        signature = signature
    }
end

--------------------------------------------------------------------------------

return M