-- file: lua/Halt.lua

local http = require 'http'
local backend = require 'backend'


local char = string.char
local byte = string.byte
local find = string.find
local sub = string.sub

local ADDRESS = backend.ADDRESS
local PROXY = backend.PROXY
local DIRECT_WRITE = backend.SUPPORT.DIRECT_WRITE

local SUCCESS = backend.RESULT.SUCCESS
local HANDSHAKE = backend.RESULT.HANDSHAKE
local DIRECT = backend.RESULT.DIRECT

local ctx_uuid = backend.get_uuid
local ctx_proxy_type = backend.get_proxy_type
local ctx_address_type = backend.get_address_type
local ctx_address_host = backend.get_address_host
local ctx_address_bytes = backend.get_address_bytes
local ctx_address_port = backend.get_address_port
local ctx_write = backend.write
local ctx_free = backend.free
local ctx_debug = backend.debug

local is_http_request = http.is_http_request

local flags = {}
local marks = {}
local kHttpHeaderSent = 1
local kHttpHeaderRecived = 2

function wa_lua_on_flags_cb(ctx)
    return 0
end

function wa_lua_on_handshake_cb(ctx)
    local uuid = ctx_uuid(ctx)

    if ( ctx_address_port(ctx) == 80 ) then
        flags[uuid] = kHttpHeaderRecived
    end

    -- local proxy_type = ctx_proxy_type(ctx)

    -- if proxy_type == PROXY.HTTP_TUNNEL then
    --     ctx_debug('proxy_type -- ' .. ctx_address_host(ctx) .. ' -- ' .. 'PROXY.HTTP_TUNNEL')
    -- elseif proxy_type == PROXY.SOCKS_TUNNEL then
    --     ctx_debug('proxy_type -- ' .. ctx_address_host(ctx) .. ' -- ' .. 'PROXY.SOCKS_TUNNEL')
    -- else
    --     ctx_debug('proxy_type -- ' .. ctx_address_host(ctx) .. ' -- ' .. 'none')
    -- end


    if flags[uuid] == kHttpHeaderRecived then
        return true
    end
    
    local res = nil
    

    if flags[uuid] ~= kHttpHeaderSent then
        local host = ctx_address_host(ctx)
        local port = ctx_address_port(ctx)
        

        res = 'CONNECT ' .. host .. ':' .. port ..'@down.dingtalk.com HTTP/1.1\r\n' ..
                    'Host: down.dingtalk.com\r\n' ..
                    'Proxy-Connection: Keep-Alive\r\n'..
                    'X-T5-Auth: YTY0Nzlk\r\n' ..
                    'User-Agent: dingdingboxapp\r\n\r\n'
          
        ctx_write(ctx, res)
        flags[uuid] = kHttpHeaderSent
    end

    return false
end

function wa_lua_on_read_cb(ctx, buf)

    local uuid = ctx_uuid(ctx)
    if flags[uuid] == kHttpHeaderSent then
        flags[uuid] = kHttpHeaderRecived
        return HANDSHAKE, nil
    end

    return DIRECT, buf
end

function wa_lua_on_write_cb(ctx, buf)
 
    local host = ctx_address_host(ctx)
    local port = ctx_address_port(ctx)

    -- ctx_debug('buffer -- ' .. 'before' .. ' -- ' .. buf)
    
    if ( is_http_request(buf) == 1 ) then
            local index, tmp = find(buf, '/')
            local method = sub(buf, 1, index - 2)
            -- local rest = sub(buf, index)
            -- local s, e = find(rest, '\r\n')

            -- local rest = sub(buf, index)
            local s, e = find(buf, '\r\n')
            
            -- local less = sub(rest, e + 1)
            -- local s1, e1 = find(less, '\r\n')

            -- buf = sub(buf, 1, e) .. 
            buf = method .. ' http://' .. host .. ':' .. port .. sub(buf, index, e) ..
            '@down.dingtalk.com\r\n'..
            'X-T5-Auth: YTY0Nzlk\r\n' ..
            'User-Agent: dingdingboxapp\r\n' ..
            sub(buf, e + 1)

            -- ctx_debug('buffer -- ' .. host .. ' -- ' .. buf)

            ctx_write(ctx, buf)
            return SUCCESS, nil
            
    end
    
    return DIRECT, buf
end

function wa_lua_on_close_cb(ctx)
    local uuid = ctx_uuid(ctx)
    flags[uuid] = nil
    ctx_free(ctx)
    return SUCCESS
end