package main

import (
	"database/sql"
	"fmt"
	"path/filepath"

	"fn-registry/functions/infra"
)

// OpenConnections opens all database connections defined in the config.
// basePath is the directory of the YAML file — file-based drivers (sqlite, duckdb)
// resolve relative paths from there.
func OpenConnections(conns map[string]ConnConfig, basePath string) (map[string]*sql.DB, error) {
	pool := make(map[string]*sql.DB, len(conns))

	for name, cfg := range conns {
		db, err := openOne(name, cfg, basePath)
		if err != nil {
			// Close already opened connections on failure.
			CloseConnections(pool)
			return nil, err
		}
		pool[name] = db
	}

	return pool, nil
}

func openOne(name string, cfg ConnConfig, basePath string) (*sql.DB, error) {
	switch cfg.Driver {
	case "sqlite":
		return infra.SQLiteOpen(cfg.Path, basePath)
	case "postgres":
		port := cfg.Port
		if port == 0 {
			port = 5432
		}
		return infra.PostgresOpen(cfg.Host, port, cfg.User, cfg.Password, cfg.Database, cfg.SSLMode)
	case "duckdb":
		p := cfg.Path
		if basePath != "" && p != "" && p != ":memory:" && !filepath.IsAbs(p) {
			p = filepath.Join(basePath, p)
		}
		return infra.DuckDBOpen(p)
	case "clickhouse":
		port := cfg.Port
		if port == 0 {
			port = 9000
		}
		return infra.ClickHouseOpen(cfg.Host, port, cfg.User, cfg.Password, cfg.Database)
	default:
		return nil, fmt.Errorf("connection %q: unsupported driver %q", name, cfg.Driver)
	}
}

// CloseConnections closes all database connections.
func CloseConnections(pool map[string]*sql.DB) {
	for _, db := range pool {
		infra.DBClose(db)
	}
}