package ent

import (
	"context"
	"fmt"

	"github.com/jackc/pgx/v5/pgxpool"

	sharedpostgres "knowfoolery/backend/shared/infra/database/postgres"
)

// Client wraps the pgx pool used by repository implementations.
type Client struct {
	Pool *pgxpool.Pool
}

// NewClient creates a persistence client and verifies connectivity.
func NewClient(ctx context.Context, cfg sharedpostgres.Config) (*Client, error) {
	poolCfg, err := pgxpool.ParseConfig(cfg.URL())
	if err != nil {
		return nil, fmt.Errorf("parse postgres config: %w", err)
	}
	poolCfg.MaxConns = clampIntToInt32(cfg.MaxOpenConns)
	poolCfg.MinConns = clampIntToInt32(cfg.MaxIdleConns)
	poolCfg.MaxConnLifetime = cfg.ConnMaxLifetime
	poolCfg.MaxConnIdleTime = cfg.ConnMaxIdleTime

	pool, err := pgxpool.NewWithConfig(ctx, poolCfg)
	if err != nil {
		return nil, fmt.Errorf("create postgres pool: %w", err)
	}

	if err := pool.Ping(ctx); err != nil {
		pool.Close()
		return nil, fmt.Errorf("ping postgres: %w", err)
	}

	return &Client{Pool: pool}, nil
}

// Close closes the underlying pool.
func (c *Client) Close() {
	if c != nil && c.Pool != nil {
		c.Pool.Close()
	}
}

func clampIntToInt32(v int) int32 {
	const maxInt32 = int(^uint32(0) >> 1)
	if v <= 0 {
		return 0
	}
	if v > maxInt32 {
		return int32(maxInt32)
	}
	return int32(v)
}