package config

import (
	"encoding/json"
	"errors"
	"os"
	"path/filepath"
	"strings"

	db_config "scroll-tech/database"
)

const (
	defaultNumberOfVerifierWorkers      = 10
	defaultNumberOfSessionRetryAttempts = 2
)

// RollerManagerConfig loads sequencer configuration items.
type RollerManagerConfig struct {
	PauseSendTask      bool   `json:"pause_send_task"`
	PauseSendTaskUntil uint64 `json:"pause_send_task_until"`
	CompressionLevel   int    `json:"compression_level,omitempty"`
	// asc or desc (default: asc)
	OrderSession string `json:"order_session,omitempty"`
	// The amount of rollers to pick per proof generation session.
	RollersPerSession uint8 `json:"rollers_per_session"`
	// Number of attempts that a session can be retried if previous attempts failed.
	// Currently we only consider proving timeout as failure here.
	SessionAttempts uint8 `json:"session_attempts,omitempty"`
	// Zk verifier config.
	Verifier *VerifierConfig `json:"verifier,omitempty"`
	// Proof collection time (in minutes).
	CollectionTime int `json:"collection_time"`
	// Token time to live (in seconds)
	TokenTimeToLive int `json:"token_time_to_live"`
	// Max number of workers in verifier worker pool
	MaxVerifierWorkers int `json:"max_verifier_workers,omitempty"`
}

// L2Config loads l2geth configuration items.
type L2Config struct {
	// l2geth node url.
	Endpoint string `json:"endpoint"`
}

// Config load configuration items.
type Config struct {
	RollerManagerConfig *RollerManagerConfig `json:"roller_manager_config"`
	DBConfig            *db_config.DBConfig  `json:"db_config"`
	L2Config            *L2Config            `json:"l2_config"`
}

// VerifierConfig load zk verifier config.
type VerifierConfig struct {
	MockMode   bool   `json:"mock_mode"`
	ParamsPath string `json:"params_path"`
	AggVkPath  string `json:"agg_vk_path"`
}

// NewConfig returns a new instance of Config.
func NewConfig(file string) (*Config, error) {
	buf, err := os.ReadFile(filepath.Clean(file))
	if err != nil {
		return nil, err
	}

	cfg := &Config{}
	err = json.Unmarshal(buf, cfg)
	if err != nil {
		return nil, err
	}

	// Check roller's order session
	order := strings.ToUpper(cfg.RollerManagerConfig.OrderSession)
	if len(order) > 0 && !(order == "ASC" || order == "DESC") {
		return nil, errors.New("roller config's order session is invalid")
	}
	cfg.RollerManagerConfig.OrderSession = order

	if cfg.RollerManagerConfig.MaxVerifierWorkers == 0 {
		cfg.RollerManagerConfig.MaxVerifierWorkers = defaultNumberOfVerifierWorkers
	}
	if cfg.RollerManagerConfig.SessionAttempts == 0 {
		cfg.RollerManagerConfig.SessionAttempts = defaultNumberOfSessionRetryAttempts
	}

	return cfg, nil
}