package rpc

import (
	"context"
	"encoding/json"
	"log/slog"

	agentpb "git.ipao.vip/rogee/go-sip/gen/agent"
	"git.ipao.vip/rogee/go-sip/internal/asterisk"
	"git.ipao.vip/rogee/go-sip/internal/configread"
	"google.golang.org/grpc/codes"
	"google.golang.org/grpc/status"
)

// ApplySIP is deliberately unavailable on the Mock call server. A native
// Agent accepts a complete Dispatcher-owned snapshot, then reports
// only revisions it actually applied and inspected in native Asterisk.
func (s *Server) ApplySIP(ctx context.Context, req *agentpb.ApplySIPRequest) (*agentpb.ApplySIPResponse, error) {
	if req == nil || req.Meta == nil || len(req.ApprovedSnapshotJson) == 0 || len(req.ApprovedSnapshotJson) > 1<<20 {
		return nil, status.Error(codes.InvalidArgument, "approved SIP request or bounded snapshot is required")
	}
	if err := s.authorize(ctx, req.Meta); err != nil {
		return nil, err
	}
	dispatcherID, err := s.sessions.ApprovedDispatcher(req.Meta, s.now())
	if err != nil {
		return nil, err
	}
	if (s.mode != "sip-only" && s.mode != "nonprod-real") || s.applySIP == nil {
		return nil, status.Error(codes.FailedPrecondition, "real SIP apply is unavailable on this Agent")
	}
	var approved configread.SIP
	if err := json.Unmarshal(req.ApprovedSnapshotJson, &approved); err != nil || approved.DispatcherID != dispatcherID || approved.Revision <= 0 {
		return nil, status.Error(codes.InvalidArgument, "SIP snapshot owner or content is invalid")
	}
	if _, err := asterisk.Render(approved); err != nil {
		return nil, status.Error(codes.InvalidArgument, "SIP snapshot is not approved for native reload")
	}
	var trunks []struct {
		ID      string `json:"trunk_id"`
		Enabled bool   `json:"enabled"`
	}
	if err := json.Unmarshal(approved.Trunks, &trunks); err != nil {
		return nil, status.Error(codes.InvalidArgument, "SIP trunk list is invalid")
	}
	expected := make(map[string]bool)
	for _, trunk := range trunks {
		if trunk.Enabled {
			expected[trunk.ID] = true
		}
	}
	s.sipMu.Lock()
	defer s.sipMu.Unlock()
	loaded, err := s.applySIP(ctx, req.ApprovedSnapshotJson)
	if err != nil {
		slog.Error("native SIP apply failed", "dispatcher_id", dispatcherID, "revision", approved.Revision, "error", err)
		return nil, status.Error(codes.Unavailable, "native Asterisk SIP reload failed")
	}
	if len(loaded) != len(expected) {
		slog.Error("native SIP loaded-set mismatch", "dispatcher_id", dispatcherID, "revision", approved.Revision, "expected_count", len(expected), "loaded_count", len(loaded))
		return nil, status.Error(codes.Unavailable, "native Asterisk SIP loaded-set mismatch")
	}
	for trunk, revision := range loaded {
		if !expected[trunk] || revision != approved.Revision {
			slog.Error("native SIP loaded-revision mismatch", "dispatcher_id", dispatcherID, "revision", approved.Revision, "trunk_id", trunk, "observed_revision", revision)
			return nil, status.Error(codes.Unavailable, "native Asterisk SIP loaded-revision mismatch")
		}
	}
	slog.Info("native Asterisk SIP revision confirmed", "dispatcher_id", dispatcherID, "revision", approved.Revision, "trunk_count", len(loaded))
	return &agentpb.ApplySIPResponse{TrunkRevision: loaded}, nil
}