package main

import (
	"bytes"
	"context"
	"errors"
	"log"
	"maps"
	"net"
	"net/http"
	"os"
	"reflect"
	"slices"
	"strings"
	"time"

	agentpb "git.ipao.vip/rogee/go-sip/gen/agent"
	"git.ipao.vip/rogee/go-sip/internal/agent"
	"git.ipao.vip/rogee/go-sip/internal/config"
	"git.ipao.vip/rogee/go-sip/internal/rpc"
	"git.ipao.vip/rogee/go-sip/internal/tenant"
	"github.com/google/uuid"
)

// newCurrentAgentServer binds the authenticated Agent session, task controls
// and per-call Mock recording delivery. Serving the returned server requires
// a separately verified mutual-TLS listener and a pinned local D connection.
func newCurrentAgentServer(ctx context.Context, settings config.AgentEnvironment, scenario approvedMockScenario, appliedSIP map[string]int64, dispatcher agentpb.AgentControlServiceClient) (*rpc.Server, error) {
	if ctx == nil || ctx.Err() != nil || settings.AgentID == "" || settings.CellID == "" || settings.SessionPath == "" ||
		settings.RecoveryRoot == "" || len(settings.PeerFingerprints) == 0 || len(appliedSIP) == 0 ||
		scenario.MaxWAVBytes <= 44 || len(scenario.Script.Turns) == 0 || strings.TrimSpace(scenario.ReasonMessage) == "" {
		return nil, errors.New("current Agent requires an active process, explicit Mock media and deployment identity")
	}
	if tenant.ValidateDispatcherID(settings.DispatcherID) != nil {
		return nil, errors.New("current Agent requires an approved Dispatcher UUID v4")
	}
	if dispatcher == nil {
		return nil, errors.New("current Agent requires a pinned Dispatcher transport")
	}
	value := reflect.ValueOf(dispatcher)
	switch value.Kind() {
	case reflect.Chan, reflect.Func, reflect.Interface, reflect.Map, reflect.Pointer, reflect.Slice:
		if value.IsNil() {
			return nil, errors.New("current Agent requires a pinned Dispatcher transport")
		}
	}
	root, err := os.Stat(settings.RecoveryRoot)
	if err != nil || !root.IsDir() || root.Mode().Perm() != 0700 {
		return nil, errors.New("current Agent requires an existing private 0700 recovery directory")
	}
	for trunk, revision := range appliedSIP {
		if strings.TrimSpace(trunk) == "" || revision <= 0 {
			return nil, errors.New("current Agent requires explicit applied Mock SIP revisions")
		}
	}
	loaded := maps.Clone(appliedSIP)
	pins := maps.Clone(settings.PeerFingerprints)
	scenario.InboundPCM16 = bytes.Clone(scenario.InboundPCM16)
	scenario.Script.OpeningPCM16 = bytes.Clone(scenario.Script.OpeningPCM16)
	scenario.Script.Turns = slices.Clone(scenario.Script.Turns)
	for index := range scenario.Script.Turns {
		scenario.Script.Turns[index].ReplyPCM16 = bytes.Clone(scenario.Script.Turns[index].ReplyPCM16)
	}
	uploadHTTP := localMockHTTPClient()
	var handler *rpc.Server
	worker := &rpc.ApprovedCallWorker{
		Lifecycle: ctx,
		Calls:     &agent.TaskCalls{},
		Prepare: func(execution rpc.ApprovedExecution) (func(context.Context) error, error) {
			if handler == nil {
				return nil, errors.New("Agent session is unavailable")
			}
			delivery := &agent.RecordingDelivery{
				Call: agent.RecordingClient{
					Client: dispatcher, DispatcherID: execution.DispatcherID, TenantID: execution.TenantID,
					SourceEventID: execution.SourceEventID, Session: func(context.Context) (*agentpb.RequestMeta, error) { return handler.ActiveSessionMeta() },
				},
				Recovery: &agent.RecordingRecovery{
					Root:   settings.RecoveryRoot,
					Upload: agent.UploadClient{HTTPClient: uploadHTTP, AllowInsecureHTTP: true},
				},
			}
			mock := &rpc.ApprovedRecordedMockCall{
				InboundPCM16: scenario.InboundPCM16, Script: scenario.Script,
				MaxWAVBytes: scenario.MaxWAVBytes, ExpectedRecording: scenario.ExpectedRecording,
				Outcome: scenario.Outcome, ReasonMessage: scenario.ReasonMessage,
				ReportTimeout: 15 * time.Minute, Delivery: delivery,
			}
			return mock.Prepare(execution)
		},
		OnFailure: func(execution rpc.ApprovedExecution, cause error) error {
			// The runner already tried to report termination and persisted any
			// failed upload. Never invent a second result or retry an unknown PUT.
			log.Printf("Agent Mock call requires inspection: event_id=%q task_id=%q cause_type=%T", execution.SourceEventID, execution.TaskID, cause)
			return nil
		},
	}
	handler, err = rpc.NewApprovedAgentServer(rpc.ServerOptions{
		Mode: "mock", StatePath: settings.SessionPath, ApprovedDispatcherID: settings.DispatcherID,
		Status:                      &agentpb.AgentStatus{AgentId: settings.AgentID, CellId: settings.CellID, BootId: uuid.NewString(), ProtocolVersion: "agent.v1"},
		LoadedSIP:                   func(context.Context) (map[string]int64, error) { return maps.Clone(loaded), nil },
		PeerCertificateFingerprints: pins, RequirePeerCertificate: true,
	}, worker)
	if err != nil {
		return nil, err
	}
	return handler, nil
}

// The isolated Mock uploader may reach localhost only, even if a grant or
// redirect unexpectedly names a real OSS endpoint. It never logs signed URLs.
func localMockHTTPClient() *http.Client {
	transport := http.DefaultTransport.(*http.Transport).Clone()
	transport.Proxy = nil
	transport.DialContext = func(ctx context.Context, network, address string) (net.Conn, error) {
		host, _, err := net.SplitHostPort(address)
		if err != nil {
			return nil, errors.New("Mock upload target is not local")
		}
		ip := net.ParseIP(host)
		if !strings.EqualFold(host, "localhost") && (ip == nil || !ip.IsLoopback()) {
			return nil, errors.New("Mock upload target is not local")
		}
		return (&net.Dialer{}).DialContext(ctx, network, address)
	}
	return &http.Client{Transport: transport, CheckRedirect: func(*http.Request, []*http.Request) error { return http.ErrUseLastResponse }}
}