// Package config loads runtime configuration from environment variables.
//
// All env vars are prefixed with INGEST_ except shared infra ones
// (POSTGRES_DSN, REDIS_ADDR, KAFKA_BROKERS).
package config

import (
	"fmt"
	"time"

	"github.com/caarlos0/env/v11"
)

type Config struct {
	HTTPAddr            string        `env:"INGEST_HTTP_ADDR"          envDefault:":3049"`
	LogLevel            string        `env:"INGEST_LOG_LEVEL"          envDefault:"info"`
	PayloadLimitKB      int           `env:"INGEST_PAYLOAD_LIMIT_KB"   envDefault:"100"`
	BatchLimitKB        int           `env:"INGEST_BATCH_LIMIT_KB"     envDefault:"4000"`
	LateEventHours      int           `env:"INGEST_LATE_EVENT_HOURS"   envDefault:"24"`
	DedupTTLHours       int           `env:"INGEST_DEDUP_TTL_HOURS"    envDefault:"24"`
	WriteKeyCacheTTL    time.Duration `env:"INGEST_WRITE_KEY_CACHE_TTL_SECONDS" envDefault:"45s"`
	ShutdownTimeout     time.Duration `env:"INGEST_SHUTDOWN_TIMEOUT_SECONDS"    envDefault:"30s"`
	LogPayloadOnSuccess bool          `env:"INGEST_LOG_PAYLOAD_ON_SUCCESS" envDefault:"false"`
	LogPayloadOnError   bool          `env:"INGEST_LOG_PAYLOAD_ON_ERROR"   envDefault:"true"`

	// RateLimitRPS caps requests per workspace per second. 0 disables the
	// limiter entirely (use for load tests; never in production).
	RateLimitRPS int `env:"INGEST_RATE_LIMIT_RPS" envDefault:"100"`

	PostgresDSN string `env:"POSTGRES_DSN,required"`
	RedisAddr   string `env:"REDIS_ADDR"  envDefault:"localhost:6379"`

	KafkaBrokers     []string `env:"KAFKA_BROKERS" envSeparator:"," envDefault:"localhost:9092"`
	KafkaTopicIngest string   `env:"KAFKA_TOPIC_INGEST" envDefault:"events.ingest"`
	KafkaTopicDLQ    string   `env:"KAFKA_TOPIC_DLQ"    envDefault:"events.dlq"`
	KafkaTopicRetry  string   `env:"KAFKA_TOPIC_RETRY"  envDefault:"events.retry"`
}

func Load() (*Config, error) {
	cfg := &Config{}
	if err := env.Parse(cfg); err != nil {
		return nil, fmt.Errorf("config load: %w", err)
	}
	return cfg, nil
}