local exit = require "sm.utils.exit"
local config_fetcher = require "sm.utils.config_fetcher"
local string_utils = require "sm.utils.string_utils"
local cjson = require "cjson"

local _M = {}

function _M.resolve(redis, host)
    local remote_addr = ngx.var.remote_addr
    local request_id = ngx.var.request_id

    if ngx.ctx.hostname and ngx.ctx.zone_id then
        return ngx.ctx.hostname, ngx.ctx.zone_id, nil
    end

    local hostname, _, err = config_fetcher.hostname(redis, host)
    if not hostname then
        if string_utils.is_root_domain(host) then
            ngx.log(ngx.ERR, "hostname not found: " .. host)
            return nil, nil, exit.config(remote_addr, request_id)
        end

        local root_domain = string_utils.get_root_domain(host)
        hostname, _, err = config_fetcher.hostname(redis, "*." .. root_domain)
        if not hostname then
            ngx.log(ngx.ERR, "hostname not found: " .. host)
            return nil, nil, exit.config(remote_addr, request_id)
        end
    end

    local zone_id = hostname["key"]
    local site_json = cjson.encode(hostname)

    ngx.ctx.hostname = hostname
    ngx.ctx.zone_id = zone_id
    ngx.var.site = site_json
    ngx.var.zone_id = zone_id

    return hostname, zone_id, nil
end

function _M.restore_from_vars()
    if ngx.ctx.hostname and ngx.ctx.zone_id then
        return ngx.ctx.hostname, ngx.ctx.zone_id, nil
    end

    local site_json = ngx.var.site
    local zone_id = ngx.var.zone_id
    if not site_json or site_json == "" or not zone_id or zone_id == "" then
        return nil, nil, nil
    end

    local ok, hostname = pcall(cjson.decode, site_json)
    if not ok or not hostname then
        return nil, nil, nil
    end

    ngx.ctx.hostname = hostname
    ngx.ctx.zone_id = zone_id

    return hostname, zone_id, nil
end

return _M