package main

import (
	"context"
	"fmt"
	"github.com/spf13/cobra"
	"log"
	"os"
	"strconv"
)

func SetupDatabaseConnection(cmd *cobra.Command, args []string) {
	dbPort, _ := strconv.Atoi(os.Getenv("DB_PORT"))

	db := NewDatabase(os.Getenv("DB_HOST"), dbPort)
	err := db.Connect(os.Getenv("DB_USER"), os.Getenv("DB_PASSWORD"), os.Getenv("DB_NAME"))

	if err != nil {
		log.Printf("Failed to connect to the database: %s", err)
		os.Exit(1)
	}

	cmd.SetContext(context.WithValue(cmd.Context(), "db", db))
}

func NewCli() *cobra.Command {
	cli := &cobra.Command{
		Use:   "cobble",
		Short: "Cobble is a simple SQL migration utility.",
	}

	up := &cobra.Command{
		Use:    "up",
		Short:  "Applies migrations",
		PreRun: SetupDatabaseConnection,
		Run: func(cmd *cobra.Command, args []string) {
			db := cmd.Context().Value("db").(DB)
			migrationRoot := args[0]
			migrationGraph, _ := NewMigrationGraphFromDirectory(migrationRoot)
			migrationHistory, _ := migrationGraph.GetLinearHistory()
			for _, migration := range migrationHistory {
				log.Printf("%s", migration.Name)
				if err := migration.Apply(db); err != nil {
					os.Exit(1)
				}
			}
		},
	}

	inspect := &cobra.Command{
		Use:   "inspect",
		Short: "Prints the nth migration in the history",
		Run: func(cmd *cobra.Command, args []string) {
			migrationRoot, _ := cmd.Flags().GetString("root")
			migrationIndex, _ := cmd.Flags().GetInt("index")

			migrationGraph, _ := NewMigrationGraphFromDirectory(migrationRoot)
			migrationHistory, _ := migrationGraph.GetLinearHistory()
			migration := migrationHistory[migrationIndex]
			sql, _ := migration.Sql()
			fmt.Printf("%s:\n%s", migration.Name, sql)
		},
	}
	cli.AddCommand(up)
	cli.AddCommand(inspect)

	cli.PersistentFlags().StringP("root", "r", "./migrations", "Root directory where migration files live.")
	inspect.PersistentFlags().IntP("index", "i", 0, "Zero-based index of the migration to target.")

	inspect.MarkFlagRequired("index")

	return cli
}

func main() {
	if err := NewCli().Execute(); err != nil {
		log.Fatal(err)
		os.Exit(1)
	}
}