// vtest retry: 3
// vtest vflags: -d use_openssl
// vtest build: !windows
module http

import encoding.base64
import net
import net.mbedtls
import net.urllib
import os
import time

const sample_proxy_url = 'https://localhost'
const sample_auth_proxy_url = 'http://user:pass@localhost:8888'

const sample_host = '127.0.0.1:1337'
const sample_request = &Request{
    url: 'http://${sample_host}'
}
const sample_path = '/'
const proxy_https_request_count = 12
const proxy_https_test_cert_path = @VEXEROOT +
    '/vlib/net/websocket/tests/autobahn/fuzzing_server_wss/config/server.crt'
const proxy_https_test_key_path = @VEXEROOT +
    '/vlib/net/websocket/tests/autobahn/fuzzing_server_wss/config/server.key'

fn test_proxy_fields() ? {
    sample_proxy := new_http_proxy(sample_proxy_url)!
    sample_auth_proxy := new_http_proxy(sample_auth_proxy_url)!

    assert sample_proxy.scheme == 'https'
    assert sample_proxy.host == 'localhost:443'
    assert sample_proxy.hostname == 'localhost'
    assert sample_proxy.port == 443
    assert sample_proxy.url == sample_proxy_url
    assert sample_auth_proxy.scheme == 'http'
    assert sample_auth_proxy.username == 'user'
    assert sample_auth_proxy.password == 'pass'
    assert sample_auth_proxy.host == 'localhost:8888'
    assert sample_auth_proxy.hostname == 'localhost'
    assert sample_auth_proxy.port == 8888
    assert sample_auth_proxy.url == sample_auth_proxy_url
}

fn test_proxy_headers() ? {
    sample_proxy := new_http_proxy(sample_proxy_url)!
    headers := sample_proxy.build_proxy_headers(sample_host)

    assert headers == 'CONNECT 127.0.0.1:1337 HTTP/1.1\r\n' + 'Host: 127.0.0.1\r\n' +
        'Proxy-Connection: Keep-Alive\r\n\r\n'
}

fn test_proxy_headers_authenticated() ? {
    sample_proxy := new_http_proxy(sample_auth_proxy_url)!
    headers := sample_proxy.build_proxy_headers(sample_host)

    auth_token := base64.encode(('${sample_proxy.username}:' + '${sample_proxy.password}').bytes())

    assert headers == 'CONNECT 127.0.0.1:1337 HTTP/1.1\r\n' + 'Host: 127.0.0.1\r\n' +
        'Proxy-Connection: Keep-Alive\r\nProxy-Authorization: Basic ${auth_token}\r\n\r\n'
}

enum ProxyTunnelCopyResult {
    data
    timeout
    closed
}

fn count_open_file_descriptors() int {
    $if windows {
        return 0
    } $else {
        fds := os.ls('/dev/fd') or { return 0 }
        return fds.len
    }
}

fn start_https_proxy_test_target_server() !(int, chan bool) {
    ready := chan int{cap: 1}
    done := chan bool{cap: 1}
    spawn fn [ready, done] () {
        mut port_listener := net.listen_tcp(.ip, '127.0.0.1:0') or { panic(err) }
        port := int((port_listener.addr() or { panic(err) }).port() or { panic(err) })
        port_listener.close() or {}
        mut listener := mbedtls.new_ssl_listener('127.0.0.1:${port}', mbedtls.SSLConnectConfig{
            cert:                   proxy_https_test_cert_path
            cert_key:               proxy_https_test_key_path
            validate:               false
            in_memory_verification: false
        }) or { panic(err) }
        ready <- port
        defer {
            listener.shutdown() or {}
            done <- true
        }
        for _ in 0 .. proxy_https_request_count {
            mut conn := listener.accept() or { panic(err) }
            handle_https_proxy_test_target_connection(mut conn)
        }
    }()
    return <-ready, done
}

fn handle_https_proxy_test_target_connection(mut conn mbedtls.SSLConn) {
    defer {
        conn.shutdown() or {}
    }
    mut request_buf := []u8{len: 2048}
    _ = conn.read(mut request_buf) or { return }
    conn.write_string('HTTP/1.1 200 OK\r\nContent-Length: 2\r\nConnection: close\r\n\r\nok') or {
        return
    }
}

fn start_https_proxy_test_server(target_port int) !(int, chan bool) {
    ready := chan int{cap: 1}
    done := chan bool{cap: 1}
    spawn fn [ready, done, target_port] () {
        mut listener := net.listen_tcp(.ip, '127.0.0.1:0') or { panic(err) }
        port := int((listener.addr() or { panic(err) }).port() or { panic(err) })
        ready <- port
        mut workers := []thread{cap: proxy_https_request_count}
        for _ in 0 .. proxy_https_request_count {
            mut client := listener.accept() or { panic(err) }
            workers << spawn handle_https_proxy_test_tunnel(mut client, target_port)
        }
        listener.close() or {}
        workers.wait()
        done <- true
    }()
    return <-ready, done
}

fn handle_https_proxy_test_tunnel(mut client net.TcpConn, target_port int) {
    defer {
        client.close() or {}
    }
    request := read_proxy_request(mut client) or { return }
    if !request.starts_with('CONNECT 127.0.0.1:${target_port} HTTP/1.1\r\n') {
        client.write_string('HTTP/1.1 400 Bad Request\r\n\r\n') or {}
        return
    }
    mut upstream := net.dial_tcp('127.0.0.1:${target_port}') or {
        client.write_string('HTTP/1.1 502 Bad Gateway\r\n\r\n') or {}
        return
    }
    defer {
        upstream.close() or {}
    }
    client.write_string('HTTP/1.1 200 Connection Established\r\n\r\n') or { return }
    client.set_read_timeout(50 * time.millisecond)
    upstream.set_read_timeout(50 * time.millisecond)
    deadline := time.now().add(2 * time.second)
    for time.now() < deadline {
        client_state := copy_https_proxy_test_tunnel_data(mut client, mut upstream)
        upstream_state := copy_https_proxy_test_tunnel_data(mut upstream, mut client)
        if client_state == .closed || upstream_state == .closed {
            return
        }
    }
}

fn read_proxy_request(mut conn net.TcpConn) !string {
    mut total_bytes_read := 0
    mut msg := [4096]u8{}
    mut buffer := [1]u8{}
    for total_bytes_read < msg.len {
        bytes_read := conn.read_ptr(&buffer[0], 1)!
        if bytes_read == 0 {
            return error('unexpected EOF while reading proxy request')
        }
        msg[total_bytes_read] = buffer[0]
        total_bytes_read++
        if total_bytes_read > 3 && msg[total_bytes_read - 1] == `\n`
            && msg[total_bytes_read - 2] == `\r` && msg[total_bytes_read - 3] == `\n`
            && msg[total_bytes_read - 4] == `\r` {
            return msg[..total_bytes_read].bytestr()
        }
    }
    return error('proxy request headers exceeded 4096 bytes')
}

fn copy_https_proxy_test_tunnel_data(mut src net.TcpConn, mut dst net.TcpConn) ProxyTunnelCopyResult {
    mut buf := []u8{len: 1024}
    bytes_read := src.read(mut buf) or {
        if err.code() == net.err_timed_out_code {
            return .timeout
        }
        return .closed
    }
    if bytes_read <= 0 {
        return .closed
    }
    dst.write(buf[..bytes_read]) or { return .closed }
    return .data
}

fn test_https_proxy_requests_do_not_leak_sockets() ! {
    $if windows {
        return
    }
    $if sanitized_job ? {
        return
    }
    $if tinyc {
        // TinyCC hangs in the bundled mbedtls handshake path on linux CI.
        return
    }
    target_port, target_done := start_https_proxy_test_target_server()!
    proxy_port, proxy_done := start_https_proxy_test_server(target_port)!
    baseline_fds := count_open_file_descriptors()
    proxy := new_http_proxy('http://127.0.0.1:${proxy_port}')!
    for _ in 0 .. proxy_https_request_count {
        resp := fetch(
            method:   .get
            url:      'https://127.0.0.1:${target_port}/'
            proxy:    proxy
            validate: false
        )!
        assert resp.status_code == 200
        assert resp.body == 'ok'
    }
    _ = <-target_done
    _ = <-proxy_done
    time.sleep(100 * time.millisecond)
    final_fds := count_open_file_descriptors()
    assert final_fds <= baseline_fds + 3
}

fn test_http_proxy_do() {
    env := os.environ()
    mut env_proxy := ''

    for envvar in ['http_proxy', 'HTTP_PROXY', 'https_proxy', 'HTTPS_PROXY'] {
        prox_val := env[envvar] or { continue }
        if prox_val != '' {
            env_proxy = env[envvar]
        }
    }
    if env_proxy != '' {
        println('Has usable proxy env vars')
        proxy := new_http_proxy(env_proxy)!
        mut header := new_header(key: .user_agent, value: 'vlib')
        header.add_custom('X-Vlang-Test', 'proxied')!
        res := proxy.http_do(urllib.parse('http://httpbin.org/headers')!, Method.get, '/headers', &Request{
            proxy:  proxy
            header: header
        }, '', header)!
        println(res.status_code)
        println('he4aders ${res.header}')
        assert res.status_code == 200
        // assert res.header.data['X-Vlang-Test'] == 'proxied'
    } else {
        println('Proxy env vars (HTTP_PROXY or HTTPS_PROXY) not set. Skipping test.')
    }
}

const multipart_https_payload_len = 20 * 1024 + 137

fn test_https_multipart_form_preserves_large_binary_body() ! {
    $if tinyc {
        // TinyCC hangs in the bundled mbedtls handshake path on linux CI.
        return
    }
    mut port_listener := net.listen_tcp(.ip, '127.0.0.1:0')!
    port := port_listener.addr()!.port()!
    port_listener.close()!

    payload := multipart_https_test_payload()
    form := {
        'alpha': 'beta'
    }
    files := {
        'file': [
            FileData{
                filename:     'payload.bin'
                content_type: 'application/octet-stream'
                data:         payload
            },
        ]
    }
    body, boundary := multipart_form_body(form, files)

    mut listener := mbedtls.new_ssl_listener('127.0.0.1:${port}', mbedtls.SSLConnectConfig{
        cert:     proxy_https_test_cert_path
        cert_key: proxy_https_test_key_path
        validate: false
    })!
    server := spawn multipart_https_serve_once(mut listener, body, boundary, form, files)

    mut header := new_header()
    header.set(.content_type, 'multipart/form-data; boundary="${boundary}"')
    resp := fetch(
        method:   .post
        url:      'https://127.0.0.1:${port}/upload'
        header:   header
        data:     body
        validate: false
    )!
    server.wait()

    assert resp.status_code == 200
    assert resp.body == 'ok'
}

fn multipart_https_test_payload() string {
    mut payload := []u8{len: multipart_https_payload_len, init: u8(((index * 17) % 250) + 1)}
    payload[127] = 0
    payload[4096] = 0
    payload[16 * 1024] = 0
    payload[payload.len - 1] = `!`
    return payload.bytestr()
}

fn multipart_https_serve_once(mut listener mbedtls.SSLListener, expected_body string, boundary string, expected_form map[string]string, expected_files map[string][]FileData) {
    defer {
        listener.shutdown() or {}
    }
    mut conn := listener.accept() or { panic(err) }
    conn.set_read_timeout(5 * time.second)
    defer {
        conn.shutdown() or {}
    }

    request_text := read_https_request(mut conn) or { panic(err) }
    req := parse_request_str(request_text) or { panic(err) }

    assert req.method == .post
    assert req.url == '/upload'
    assert req.data == expected_body
    assert req.data.len == expected_body.len
    assert req.header.get(.content_length) or { panic(err) } == expected_body.len.str()
    assert req.header.get(.content_type) or { panic(err) } == 'multipart/form-data; boundary="${boundary}"'

    form, files := parse_multipart_form(req.data, boundary)
    assert form == expected_form
    assert files == expected_files

    conn.write_string('HTTP/1.1 200 OK\r\nContent-Length: 2\r\nConnection: close\r\n\r\nok') or {
        panic(err)
    }
}

fn read_https_request(mut conn mbedtls.SSLConn) !string {
    mut request := []u8{}
    mut buf := []u8{len: 1024}
    mut content_length := -1
    mut headers_end := -1

    for {
        n := conn.read(mut buf) or {
            if err.code() == net.err_timed_out_code {
                return error('timed out while reading HTTPS request')
            }
            return err
        }
        if n <= 0 {
            break
        }
        request << buf[..n]

        request_str := request.bytestr()
        if headers_end == -1 {
            headers_end = request_str.index('\r\n\r\n') or { -1 }
            if headers_end != -1 {
                headers := request_str[..headers_end]
                for line in headers.split('\r\n') {
                    if line.to_lower().starts_with('content-length:') {
                        content_length = line.all_after(':').trim_space().int()
                        break
                    }
                }
            }
        }

        if headers_end != -1 && content_length >= 0 {
            body_start := headers_end + 4
            if request.len - body_start >= content_length {
                break
            }
        }
    }

    if headers_end == -1 {
        return error('HTTPS request did not include a full header block')
    }
    if content_length < 0 {
        return error('HTTPS request did not include Content-Length')
    }
    body_start := headers_end + 4
    if request.len - body_start < content_length {
        return error('HTTPS request body was truncated: expected ${content_length} bytes, got ${request.len - body_start}')
    }
    return request.bytestr()
}