package serverimp

import (
	"context"
	"os"
	"strings"
	"time"

	"github.com/tech/sendico/billing/fees/internal/service/fees"
	"github.com/tech/sendico/billing/fees/storage"
	mongostorage "github.com/tech/sendico/billing/fees/storage/mongo"
	oracleclient "github.com/tech/sendico/fx/oracle/client"
	"github.com/tech/sendico/pkg/api/routers"
	"github.com/tech/sendico/pkg/db"
	msg "github.com/tech/sendico/pkg/messaging"
	"github.com/tech/sendico/pkg/mlogger"
	"github.com/tech/sendico/pkg/server/grpcapp"
	"go.uber.org/zap"
	"gopkg.in/yaml.v3"
)

type Imp struct {
	logger       mlogger.Logger
	file         string
	debug        bool
	config       *config
	app          *grpcapp.App[storage.Repository]
	oracleClient oracleclient.Client
	service      *fees.Service
}

type config struct {
	*grpcapp.Config `yaml:",inline"`
	Oracle          OracleConfig `yaml:"oracle"`
}

type OracleConfig struct {
	Address           string `yaml:"address"`
	DialTimeoutSecs   int    `yaml:"dial_timeout_seconds"`
	CallTimeoutSecs   int    `yaml:"call_timeout_seconds"`
	InsecureTransport bool   `yaml:"insecure"`
}

func (c OracleConfig) dialTimeout() time.Duration {
	if c.DialTimeoutSecs <= 0 {
		return 5 * time.Second
	}
	return time.Duration(c.DialTimeoutSecs) * time.Second
}

func (c OracleConfig) callTimeout() time.Duration {
	if c.CallTimeoutSecs <= 0 {
		return 3 * time.Second
	}
	return time.Duration(c.CallTimeoutSecs) * time.Second
}

// Create initialises the billing fees server implementation.
func Create(logger mlogger.Logger, file string, debug bool) (*Imp, error) {
	return &Imp{
		logger: logger.Named("server"),
		file:   file,
		debug:  debug,
	}, nil
}

func (i *Imp) Shutdown() {
	if i.app == nil {
		if i.service != nil {
			i.service.Shutdown()
		}
		if i.oracleClient != nil {
			_ = i.oracleClient.Close()
		}
		return
	}

	timeout := 15 * time.Second
	if i.config != nil && i.config.Runtime != nil {
		timeout = i.config.Runtime.ShutdownTimeout()
	}

	if i.service != nil {
		i.service.Shutdown()
	}

	ctx, cancel := context.WithTimeout(context.Background(), timeout)
	i.app.Shutdown(ctx)
	cancel()

	if i.oracleClient != nil {
		_ = i.oracleClient.Close()
	}
}

func (i *Imp) Start() error {
	cfg, err := i.loadConfig()
	if err != nil {
		return err
	}
	i.config = cfg

	repoFactory := func(logger mlogger.Logger, conn *db.MongoConnection) (storage.Repository, error) {
		return mongostorage.New(logger, conn)
	}

	var oracleClient oracleclient.Client
	if addr := strings.TrimSpace(cfg.Oracle.Address); addr != "" {
		dialCtx, cancel := context.WithTimeout(context.Background(), cfg.Oracle.dialTimeout())
		defer cancel()

		oc, err := oracleclient.New(dialCtx, oracleclient.Config{
			Address:     addr,
			DialTimeout: cfg.Oracle.dialTimeout(),
			CallTimeout: cfg.Oracle.callTimeout(),
			Insecure:    cfg.Oracle.InsecureTransport,
		})
		if err != nil {
			i.logger.Warn("failed to initialise oracle client", zap.String("address", addr), zap.Error(err))
		} else {
			oracleClient = oc
			i.oracleClient = oc
			i.logger.Info("connected to oracle service", zap.String("address", addr))
		}
	}

	serviceFactory := func(logger mlogger.Logger, repo storage.Repository, producer msg.Producer) (grpcapp.Service, error) {
		opts := []fees.Option{}
		if oracleClient != nil {
			opts = append(opts, fees.WithOracleClient(oracleClient))
		}
		svc := fees.NewService(logger, repo, producer, opts...)
		i.service = svc
		return svc, nil
	}

	app, err := grpcapp.NewApp(i.logger, "billing_fees", cfg.Config, i.debug, repoFactory, serviceFactory)
	if err != nil {
		return err
	}
	i.app = app

	return i.app.Start()
}

func (i *Imp) loadConfig() (*config, error) {
	data, err := os.ReadFile(i.file)
	if err != nil {
		i.logger.Error("Could not read configuration file", zap.String("config_file", i.file), zap.Error(err))
		return nil, err
	}

	cfg := &config{Config: &grpcapp.Config{}}
	if err := yaml.Unmarshal(data, cfg); err != nil {
		i.logger.Error("Failed to parse configuration", zap.Error(err))
		return nil, err
	}

	if cfg.Runtime == nil {
		cfg.Runtime = &grpcapp.RuntimeConfig{ShutdownTimeoutSeconds: 15}
	}

	if cfg.GRPC == nil {
		cfg.GRPC = &routers.GRPCConfig{
			Network:          "tcp",
			Address:          ":50060",
			EnableReflection: true,
			EnableHealth:     true,
		}
	}

	return cfg, nil
}