// vtest retry: 5
import log
import net
import net.http
import time

const atimeout = 500 * time.millisecond

fn testsuite_begin() {
    log.info(@FN)
}

fn testsuite_end() {
    log.info(@FN)
}

fn test_server_stop() {
    log.warn('${@FN} started')
    defer {
        log.warn('${@FN} finished')
    }
    mut server := &http.Server{
        accept_timeout: atimeout
    }
    t := spawn server.listen_and_serve()
    server.wait_till_running()!
    mut watch := time.new_stopwatch()
    server.stop()
    assert server.status() == .stopped
    assert watch.elapsed() < 100 * time.millisecond
    t.wait()
    assert watch.elapsed() < 999 * time.millisecond
}

fn test_server_close() {
    log.warn('${@FN} started')
    defer {
        log.warn('${@FN} finished')
    }
    mut server := &http.Server{
        accept_timeout:       atimeout
        handler:              MyHttpHandler{}
        show_startup_message: false
    }
    t := spawn server.listen_and_serve()
    server.wait_till_running()!
    mut watch := time.new_stopwatch()
    server.close()
    assert server.status() == .closed
    assert watch.elapsed() < 100 * time.millisecond
    t.wait()
    assert watch.elapsed() < 999 * time.millisecond
}

fn test_server_custom_listener() {
    log.warn('${@FN} started')
    defer {
        log.warn('${@FN} finished')
    }
    listener := net.listen_tcp(.ip6, ':8081')!
    mut server := &http.Server{
        accept_timeout:       atimeout
        listener:             listener
        show_startup_message: false
    }
    t := spawn server.listen_and_serve()
    server.wait_till_running()!
    mut watch := time.new_stopwatch()
    server.close()
    assert server.status() == .closed
    assert watch.elapsed() < 100 * time.millisecond
    t.wait()
    assert watch.elapsed() < 999 * time.millisecond
}

struct MyHttpHandler {
mut:
    counter    int
    oks        int
    not_founds int
    redirects  int
}

fn (mut handler MyHttpHandler) handle(req http.Request) http.Response {
    handler.counter++
    // eprintln('${time.now()} | counter: ${handler.counter} | ${req.method} ${req.url}\n${req.header}\n${req.data} - 200 OK\n')
    // Note: the response must not echo `req.header` wholesale — the request's
    // `Content-Length` (0 for GETs) would override the server's correct one,
    // yielding a malformed response whose declared length disagrees with its
    // body.
    mut r := http.Response{
        body: req.data + ', ${req.url}'
    }
    match req.url.all_before('?') {
        '/endpoint', '/another/endpoint' {
            r.set_status(.ok)
            handler.oks++
        }
        '/redirect_to_big' {
            r.header = http.new_header(key: .location, value: '/big')
            r.status_msg = 'Moved permanently'
            r.status_code = 301
            handler.redirects++
        }
        '/big' {
            r.body = 'xyz def '.repeat(5_000)
            r.set_status(.ok)
            handler.oks++
        }
        else {
            r.set_status(.not_found)
            handler.not_founds++
        }
    }

    r.set_version(req.version)
    return r
}

fn test_server_custom_handler() {
    log.warn('${@FN} started')
    defer {
        log.warn('${@FN} finished')
    }
    mut server := &http.Server{
        accept_timeout: atimeout
        handler:        MyHttpHandler{}
        addr:           '127.0.0.1:18197'
    }
    t := spawn server.listen_and_serve()
    server.wait_till_running()!
    x := http.fetch(url: 'http://${server.addr}/endpoint?abc=xyz', data: 'my data')!
    assert x.body == 'my data, /endpoint?abc=xyz'
    assert x.status_code == 200
    assert x.status_msg == 'OK'
    assert x.http_version == '1.1'
    y := http.fetch(url: 'http://${server.addr}/another/endpoint', data: 'abcde')!
    assert y.body == 'abcde, /another/endpoint'
    assert y.status_code == 200
    assert x.status_msg == 'OK'
    assert y.status() == .ok
    assert y.http_version == '1.1'

    http.fetch(url: 'http://${server.addr}/something/else')!

    big_url := 'http://${server.addr}/redirect_to_big'
    mut progress_calls := &ProgressCalls{}
    z := http.fetch(
        url:         big_url
        user_ptr:    progress_calls
        on_redirect: fn (req &http.Request, nredirects int, new_url string) ! {
            mut progress_calls := unsafe { &ProgressCalls(req.user_ptr) }
            eprintln('>>>>>>>> on_redirect, req.url: ${req.url} | new_url: ${new_url} | nredirects: ${nredirects}')
            progress_calls.redirected_to << new_url
        }
        on_progress: fn (req &http.Request, chunk []u8, read_so_far u64) ! {
            mut progress_calls := unsafe { &ProgressCalls(req.user_ptr) }
            eprintln('>>>>>>>> on_progress, req.url: ${req.url} | got chunk.len: ${chunk.len:5}, read_so_far: ${read_so_far:8}, chunk: ${chunk#[0..30].bytestr()}')
            progress_calls.chunks << chunk.clone()
            progress_calls.reads << read_so_far
        }
        on_finish:   fn (req &http.Request, final_size u64) ! {
            mut progress_calls := unsafe { &ProgressCalls(req.user_ptr) }
            eprintln('>>>>>>>> on_finish, req.url: ${req.url}, final_size: ${final_size}')
            progress_calls.finished_was_called = true
            progress_calls.final_size = final_size
        }
    )!
    assert z.status_code == 200
    assert z.body.starts_with('xyz')
    assert z.body.len > 10000
    assert progress_calls.final_size > 40_000
    assert progress_calls.finished_was_called
    assert progress_calls.chunks.len > 1
    assert progress_calls.reads.len > 1
    assert progress_calls.chunks[0].bytestr().starts_with('HTTP/1.1 301 Moved permanently')
    assert progress_calls.chunks[1].bytestr().starts_with('HTTP/1.1 200 OK')
    assert progress_calls.chunks.last().bytestr().contains('xyz def')
    assert progress_calls.redirected_to == ['http://${server.addr}/big']

    server.stop()
    t.wait()

    if mut server.handler is MyHttpHandler {
        assert server.handler.counter == 5
        assert server.handler.oks == 3
        assert server.handler.not_founds == 1
        assert server.handler.redirects == 1
    } else {
        assert false, 'expected MyHttpHandler, got ${typeof(server.handler).name}'
    }
}

struct ProgressCalls {
mut:
    chunks              [][]u8
    reads               []u64
    finished_was_called bool
    redirected_to       []string
    final_size          u64
}

//

struct MyCountingHandler {
mut:
    counter int
}

fn (mut handler MyCountingHandler) handle(req http.Request) http.Response {
    handler.counter++
    mut r := http.Response{
        body:   req.data + ', ${req.url}, counter: ${handler.counter}'
        header: req.header
    }
    match req.url.all_before('?') {
        '/count' {
            r.set_status(.ok)
        }
        else {
            r.set_status(.not_found)
        }
    }

    r.set_version(req.version)
    return r
}

fn test_my_counting_handler_on_random_port() {
    log.warn('${@FN} started')
    defer {
        log.warn('${@FN} finished')
    }
    mut server := &http.Server{
        show_startup_message: false
        addr:                 ''
        accept_timeout:       atimeout
        handler:              MyCountingHandler{}
        on_running:           fn (mut server http.Server) {
            spawn fn (mut server http.Server) {
                log.warn('server started')
                url := 'http://${server.addr}/count'
                log.info('fetching from url: ${url}')
                for _ in 0 .. 5 {
                    x := http.fetch(url: url, data: 'my data') or { panic(err) }
                    log.info(x.body)
                }
                server.stop()
                log.warn('server stopped')
            }(mut server)
        }
    }
    server.listen_and_serve()
    if mut server.handler is MyCountingHandler {
        dump(server.handler.counter)
        assert server.handler.counter == 5
    }
    assert true
}

//

struct MyCustomHttpHostHandler {}

fn (mut handler MyCustomHttpHostHandler) handle(req http.Request) http.Response {
    dump(req.header)
    return http.Response{
        body: 'Host was: ${req.header.get(.host) or { '-' }}'
    }
}

fn test_host_header_sent_to_server() {
    ip := '127.0.0.1'
    port := 54671
    log.warn('${@FN} started')
    defer { log.warn('${@FN} finished') }
    mut server := &http.Server{
        handler: MyCustomHttpHostHandler{}
        addr:    '${ip}:${port}'
    }
    t := spawn server.listen_and_serve()
    server.wait_till_running() or {
        estr := err.str()
        if estr == 'maximum retries reached' {
            log.error('>>>> Skipping test ${@FN} since its server could not start, err: ${err}')
            return
        }
        log.fatal(estr)
    }
    defer { server.stop() }
    dump(server.addr)
    x := http.get('http://${server.addr}/')!
    dump(x)
    assert x.status_code == 200
    assert x.status_msg == 'OK'
    assert x.body.ends_with('${ip}:${port}')
}

//

struct InvalidResponseHandler {}

fn (mut handler InvalidResponseHandler) handle(req http.Request) http.Response {
    return http.Response{
        header: http.new_header_from_map({
            http.CommonHeader.content_type: 'text/plain'
        })
    }
}

struct InvalidStatusCodeHandler {}

fn (mut handler InvalidStatusCodeHandler) handle(req http.Request) http.Response {
    return http.Response{
        body:        'broken status'
        status_code: 42
    }
}

fn test_server_normalizes_invalid_handler_response() {
    log.warn('${@FN} started')
    defer { log.warn('${@FN} finished') }
    mut server := &http.Server{
        accept_timeout:       atimeout
        handler:              InvalidResponseHandler{}
        addr:                 '127.0.0.1:18202'
        show_startup_message: false
    }
    t := spawn server.listen_and_serve()
    server.wait_till_running() or {
        estr := err.str()
        if estr == 'maximum retries reached' {
            log.error('>>>> Skipping test ${@FN} since its server could not start, err: ${err}')
            return
        }
        log.fatal(estr)
    }

    mut conn := net.dial_tcp('127.0.0.1:18202')!
    defer { conn.close() or {} }
    conn.set_read_timeout(5 * time.second)
    conn.set_write_timeout(5 * time.second)

    request := 'GET / HTTP/1.1\r\nHost: 127.0.0.1:18202\r\nConnection: close\r\n\r\n'
    conn.write(request.bytes())!
    response := read_http_response(mut conn)!
    lines := response.split('\r\n')
    assert lines[0] == 'HTTP/1.1 200 OK'
    assert response.to_lower().contains('content-type: text/plain')
    assert response.to_lower().contains('content-length: 0')

    server.stop()
    t.wait()
}

fn test_server_coerces_invalid_status_code_to_internal_server_error() {
    log.warn('${@FN} started')
    defer { log.warn('${@FN} finished') }
    mut server := &http.Server{
        accept_timeout:       atimeout
        handler:              InvalidStatusCodeHandler{}
        addr:                 '127.0.0.1:18203'
        show_startup_message: false
    }
    t := spawn server.listen_and_serve()
    server.wait_till_running() or {
        estr := err.str()
        if estr == 'maximum retries reached' {
            log.error('>>>> Skipping test ${@FN} since its server could not start, err: ${err}')
            return
        }
        log.fatal(estr)
    }

    mut conn := net.dial_tcp('127.0.0.1:18203')!
    defer { conn.close() or {} }
    conn.set_read_timeout(5 * time.second)
    conn.set_write_timeout(5 * time.second)

    request := 'GET / HTTP/1.1\r\nHost: 127.0.0.1:18203\r\nConnection: close\r\n\r\n'
    conn.write(request.bytes())!
    response := read_http_response(mut conn)!
    lines := response.split('\r\n')
    assert lines[0] == 'HTTP/1.1 500 Internal Server Error'
    assert response.ends_with('broken status')

    server.stop()
    t.wait()
}

//

struct RedirectMethodHandler {}

fn (mut handler RedirectMethodHandler) handle(req http.Request) http.Response {
    mut r := http.Response{}
    match req.url {
        '/redirect-301' {
            r.header = http.new_header(key: .location, value: '/expect-get')
            r.set_status(.moved_permanently)
        }
        '/redirect-302' {
            r.header = http.new_header(key: .location, value: '/expect-get')
            r.set_status(.found)
        }
        '/redirect-303' {
            r.header = http.new_header(key: .location, value: '/expect-get')
            r.set_status(.see_other)
        }
        '/redirect-307' {
            r.header = http.new_header(key: .location, value: '/expect-post')
            r.set_status(.temporary_redirect)
        }
        '/redirect-308' {
            r.header = http.new_header(key: .location, value: '/expect-post')
            r.set_status(.permanent_redirect)
        }
        '/expect-get' {
            if req.method == .get && req.data == '' {
                r.body = 'redirected-as-get'
                r.set_status(.ok)
            } else {
                r.body = 'expected GET without a body, got ${req.method} `${req.data}`'
                r.set_status(.method_not_allowed)
            }
        }
        '/expect-post' {
            if req.method == .post && req.data == 'payload' {
                r.body = 'preserved-post'
                r.set_status(.ok)
            } else {
                r.body = 'expected POST with payload, got ${req.method} `${req.data}`'
                r.set_status(.method_not_allowed)
            }
        }
        else {
            r.set_status(.not_found)
        }
    }

    r.set_version(req.version)
    return r
}

fn test_redirects_change_post_to_get_only_when_required() {
    log.warn('${@FN} started')
    defer { log.warn('${@FN} finished') }
    mut server := &http.Server{
        accept_timeout:       atimeout
        handler:              RedirectMethodHandler{}
        addr:                 '127.0.0.1:18204'
        show_startup_message: false
    }
    t := spawn server.listen_and_serve()
    server.wait_till_running() or {
        estr := err.str()
        if estr == 'maximum retries reached' {
            log.error('>>>> Skipping test ${@FN} since its server could not start, err: ${err}')
            return
        }
        log.fatal(estr)
    }

    for path in ['/redirect-301', '/redirect-302', '/redirect-303'] {
        resp := http.post('http://${server.addr}${path}', 'payload')!
        assert resp.status() == .ok
        assert resp.body == 'redirected-as-get'
    }

    for path in ['/redirect-307', '/redirect-308'] {
        resp := http.post('http://${server.addr}${path}', 'payload')!
        assert resp.status() == .ok
        assert resp.body == 'preserved-post'
    }

    server.stop()
    t.wait()
}

//

struct KeepAliveHandler {
mut:
    request_count int
}

fn (mut handler KeepAliveHandler) handle(req http.Request) http.Response {
    handler.request_count++
    mut r := http.Response{
        body: 'request #${handler.request_count}: ${req.url}'
    }
    r.set_status(.ok)
    r.set_version(req.version)
    // Echo back the Connection header from the request if present
    if conn := req.header.get(.connection) {
        r.header.set(.connection, conn)
    }
    return r
}

fn test_server_keep_alive() {
    log.warn('${@FN} started')
    defer { log.warn('${@FN} finished') }
    mut server := &http.Server{
        accept_timeout:       atimeout
        handler:              KeepAliveHandler{}
        addr:                 '127.0.0.1:18198'
        show_startup_message: false
    }
    t := spawn server.listen_and_serve()
    server.wait_till_running() or {
        estr := err.str()
        if estr == 'maximum retries reached' {
            log.error('>>>> Skipping test ${@FN} since its server could not start, err: ${err}')
            return
        }
        log.fatal(estr)
    }

    // Test keep-alive by sending multiple requests over a single TCP connection
    mut conn := net.dial_tcp('127.0.0.1:18198')!
    defer { conn.close() or {} }
    conn.set_read_timeout(5 * time.second)
    conn.set_write_timeout(5 * time.second)

    // Send first request with Connection: keep-alive
    request1 := 'GET /test1 HTTP/1.1\r\nHost: 127.0.0.1:18198\r\nConnection: keep-alive\r\n\r\n'
    conn.write(request1.bytes())!
    mut resp1 := read_http_response(mut conn)!
    log.info('Response 1: ${resp1}')
    assert resp1.contains('request #1')
    assert resp1.to_lower().contains('connection: keep-alive')

    // Send second request on the same connection
    request2 := 'GET /test2 HTTP/1.1\r\nHost: 127.0.0.1:18198\r\nConnection: keep-alive\r\n\r\n'
    conn.write(request2.bytes())!
    mut resp2 := read_http_response(mut conn)!
    log.info('Response 2: ${resp2}')
    assert resp2.contains('request #2')
    assert resp2.to_lower().contains('connection: keep-alive')

    // Send third request with Connection: close to end the connection
    request3 := 'GET /test3 HTTP/1.1\r\nHost: 127.0.0.1:18198\r\nConnection: close\r\n\r\n'
    conn.write(request3.bytes())!
    mut resp3 := read_http_response(mut conn)!
    log.info('Response 3: ${resp3}')
    assert resp3.contains('request #3')
    assert resp3.to_lower().contains('connection: close')

    server.stop()
    t.wait()

    // Verify all 3 requests were handled
    if mut server.handler is KeepAliveHandler {
        assert server.handler.request_count == 3
    } else {
        assert false, 'expected KeepAliveHandler, got ${typeof(server.handler).name}'
    }
}

fn test_server_keep_alive_many_requests() {
    log.warn('${@FN} started')
    defer { log.warn('${@FN} finished') }
    total_requests := 64
    mut server := &http.Server{
        accept_timeout:          atimeout
        handler:                 KeepAliveHandler{}
        addr:                    '127.0.0.1:18199'
        show_startup_message:    false
        max_keep_alive_requests: 0
    }
    t := spawn server.listen_and_serve()
    server.wait_till_running() or {
        estr := err.str()
        if estr == 'maximum retries reached' {
            log.error('>>>> Skipping test ${@FN} since its server could not start, err: ${err}')
            return
        }
        log.fatal(estr)
    }

    mut conn := net.dial_tcp('127.0.0.1:18199')!
    defer { conn.close() or {} }
    conn.set_read_timeout(5 * time.second)
    conn.set_write_timeout(5 * time.second)

    for i in 0 .. total_requests {
        path := if i % 2 == 0 { '/left' } else { '/right' }
        request := 'GET ${path}?n=${i} HTTP/1.1\r\nHost: 127.0.0.1:18199\r\nConnection: keep-alive\r\n\r\n'
        conn.write(request.bytes())!
        resp := read_http_response(mut conn)!
        assert resp.contains('request #${i + 1}')
        assert resp.contains(path)
        assert resp.to_lower().contains('connection: keep-alive')
    }

    request_done := 'GET /done HTTP/1.1\r\nHost: 127.0.0.1:18199\r\nConnection: close\r\n\r\n'
    conn.write(request_done.bytes())!
    resp_done := read_http_response(mut conn)!
    assert resp_done.contains('request #${total_requests + 1}')
    assert resp_done.contains('/done')
    assert resp_done.to_lower().contains('connection: close')

    server.stop()
    t.wait()
    if mut server.handler is KeepAliveHandler {
        assert server.handler.request_count == total_requests + 1
    } else {
        assert false, 'expected KeepAliveHandler, got ${typeof(server.handler).name}'
    }
}

fn test_server_max_keep_alive_requests() {
    log.warn('${@FN} started')
    defer { log.warn('${@FN} finished') }
    mut server := &http.Server{
        accept_timeout:          atimeout
        handler:                 KeepAliveHandler{}
        addr:                    '127.0.0.1:18200'
        show_startup_message:    false
        max_keep_alive_requests: 3 // Limit to 3 requests per connection
    }
    t := spawn server.listen_and_serve()
    server.wait_till_running() or {
        estr := err.str()
        if estr == 'maximum retries reached' {
            log.error('>>>> Skipping test ${@FN} since its server could not start, err: ${err}')
            return
        }
        log.fatal(estr)
    }

    // Test that connection closes after max_keep_alive_requests
    mut conn := net.dial_tcp('127.0.0.1:18200')!
    defer { conn.close() or {} }
    conn.set_read_timeout(5 * time.second)
    conn.set_write_timeout(5 * time.second)

    // Send first request
    request1 := 'GET /test1 HTTP/1.1\r\nHost: 127.0.0.1:18200\r\nConnection: keep-alive\r\n\r\n'
    conn.write(request1.bytes())!
    mut resp1 := read_http_response(mut conn)!
    log.info('Response 1: ${resp1}')
    assert resp1.contains('request #1')
    assert resp1.to_lower().contains('connection: keep-alive')

    // Send second request
    request2 := 'GET /test2 HTTP/1.1\r\nHost: 127.0.0.1:18200\r\nConnection: keep-alive\r\n\r\n'
    conn.write(request2.bytes())!
    mut resp2 := read_http_response(mut conn)!
    log.info('Response 2: ${resp2}')
    assert resp2.contains('request #2')
    assert resp2.to_lower().contains('connection: keep-alive')

    // Send third request - should get Connection: close since max is reached
    request3 := 'GET /test3 HTTP/1.1\r\nHost: 127.0.0.1:18200\r\nConnection: keep-alive\r\n\r\n'
    conn.write(request3.bytes())!
    mut resp3 := read_http_response(mut conn)!
    log.info('Response 3: ${resp3}')
    assert resp3.contains('request #3')
    assert resp3.to_lower().contains('connection: close'), 'Expected connection: close after max requests reached'

    server.stop()
    t.wait()

    if mut server.handler is KeepAliveHandler {
        assert server.handler.request_count == 3
    } else {
        assert false, 'expected KeepAliveHandler, got ${typeof(server.handler).name}'
    }
}

fn read_http_response(mut conn net.TcpConn) !string {
    mut response := []u8{}
    mut buf := []u8{len: 1024}
    mut content_length := -1
    mut headers_end := -1

    for {
        n := conn.read(mut buf) or { break }
        if n <= 0 {
            break
        }
        response << buf[..n]

        // Check if we have received all headers
        response_str := response.bytestr()
        if headers_end == -1 {
            headers_end = response_str.index('\r\n\r\n') or { -1 }
            if headers_end != -1 {
                // Parse Content-Length from headers
                headers := response_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
                    }
                }
            }
        }

        // Check if we have received the full response
        if headers_end != -1 && content_length >= 0 {
            body_start := headers_end + 4
            body_received := response.len - body_start
            if body_received >= content_length {
                break
            }
        }
    }

    return response.bytestr()
}