-- =========================================
-- json查询接口
-- =========================================
-- 仅允许 GET 请求
if ngx.req.get_method() ~= "GET" then
    ngx.status = ngx.HTTP_NOT_ALLOWED
    ngx.header["Content-Type"] = "application/json"
    ngx.say('{"error":"Method not allowed, only GET is supported."}')
    return ngx.exit(ngx.HTTP_NOT_ALLOWED)
end

local cjson = require "cjson.safe"

ngx.header.content_type = "application/json; charset=utf-8"

-- 获取请求路径
local uri = ngx.var.uri
-- 多个前缀匹配
local prefixes = {
    "/api/json/",
    "/api/device/json/"
}
local matched_prefix = nil
for _, prefix in ipairs(prefixes) do
    if uri:find(prefix) == 1 then
        matched_prefix = prefix
        break
    end
end
if not matched_prefix then
    ngx.status = 404
    ngx.say(cjson.encode({ code = 404, msg = "未找到匹配的前缀: " .. uri }))
    return
end
local relative_path = uri:sub(#matched_prefix + 1)

-- 默认 all.json
if relative_path == "" then
    relative_path = "all.json"
elseif not relative_path:match("%.json$") then
    relative_path = relative_path .. ".json"
end

local filepath = "/opt/course/json/" .. relative_path

-- 打开文件
local file, err = io.open(filepath, "r")
if not file then
    ngx.status = 404
    ngx.say(cjson.encode({ code = 404, msg = "未找到字典文件: " .. relative_path }))
    return
end

-- 读取文件内容
local content = file:read("*a")
file:close()

-- 校验 JSON 格式
local json_data = cjson.decode(content)
if not json_data then
    ngx.status = 500
    ngx.say(cjson.encode({ code = 500, msg = "JSON 格式错误: " .. relative_path }))
    return
end

-- 组装响应
local result = cjson.encode({code = 200, msg = "success", data = json_data})

ngx.say(result)