package database

import (
	"context"
	"embed"
	"fmt"

	"git.anthrove.art/Anthrove/otter-space-sdk/v2/internal/utils"
	otterError "git.anthrove.art/Anthrove/otter-space-sdk/v2/pkg/error"
	"git.anthrove.art/Anthrove/otter-space-sdk/v2/pkg/models"
	migrate "github.com/rubenv/sql-migrate"
	log "github.com/sirupsen/logrus"
	"go.opentelemetry.io/contrib/bridges/otellogrus"
	"go.opentelemetry.io/otel"
	"go.opentelemetry.io/otel/attribute"
	"go.opentelemetry.io/otel/trace"
	"gorm.io/driver/postgres"
	"gorm.io/gorm"
)

const tracingName = "git.anthrove.art/Anthrove/otter-space-sdk/v2/pkg/database"

var (
	//go:embed migrations/*.sql
	embedMigrations embed.FS
	client          *gorm.DB
	tracer          trace.Tracer
	logger          = log.New()
)

// Connect to the Database
func Connect(ctx context.Context, config models.DatabaseConfig) error {

	// Setup open telemetry
	tracer = otel.Tracer(tracingName)

	hook := otellogrus.NewHook(tracingName)
	logger.AddHook(hook)

	// Debug enabled?
	if config.Debug {
		log.SetLevel(log.DebugLevel)
	}

	ctx, span, localLogger := utils.SetupTracing(ctx, tracer, "Connect")
	defer span.End()

	localLogger = localLogger.WithFields(log.Fields{
		"endpoint": config.Endpoint,
		"port":     config.Port,
		"database": config.Database,
	})

	span.SetAttributes(
		attribute.String("endpoint", config.Endpoint),
		attribute.Int("port", config.Port),
		attribute.String("database", config.Database),
	)

	utils.HandleEvent(span, localLogger, "Starting database connection")

	var localSSL string
	if config.SSL {
		localSSL = "require"
	} else {
		localSSL = "disable"
	}

	dsn := fmt.Sprintf("host=%s user=%s password=%s dbname=%s port=%d sslmode=%s TimeZone=%s", config.Endpoint, config.Username, config.Password, config.Database, config.Port, localSSL, config.Timezone)
	sqlDB, err := gorm.Open(postgres.Open(dsn), &gorm.Config{})
	if err != nil {
		return utils.HandleError(ctx, span, localLogger, err)
	}

	err = migrateDatabase(ctx, sqlDB, config)
	if err != nil {
		return utils.HandleError(ctx, span, localLogger, err)
	}

	client = sqlDB
	utils.HandleEvent(span, localLogger, "Database connected successfully")
	return nil
}

// migrateDatabase handels the migration of ann SQL files in the migrations subfolder
func migrateDatabase(ctx context.Context, dbPool *gorm.DB, config models.DatabaseConfig) error {
	ctx, span, localLogger := utils.SetupTracing(ctx, tracer, "migrateDatabase")
	defer span.End()

	localLogger = localLogger.WithFields(log.Fields{
		"database": config.Database,
	})

	span.SetAttributes(
		attribute.String("database", config.Database),
	)

	utils.HandleEvent(span, localLogger, "Starting database migration")

	dialect := "postgres"
	migrations := &migrate.EmbedFileSystemMigrationSource{FileSystem: embedMigrations, Root: "migrations"}

	db, err := dbPool.DB()
	if err != nil {
		return utils.HandleError(ctx, span, localLogger, err)
	}

	n, err := migrate.Exec(db, dialect, migrations, migrate.Up)
	if err != nil {
		return utils.HandleError(ctx, span, localLogger, err)
	}

	if n != 0 {
		localLogger.Debugf("applied %d migrations!", n)
	} else {
		localLogger.Debug("nothing to migrate")
	}

	utils.HandleEvent(span, localLogger, "Database migration completed successfully")
	return nil
}

// GetGorm returns a ready to use gorm.DB client
func GetGorm(ctx context.Context) (*gorm.DB, error) {
	ctx, span, localLogger := utils.SetupTracing(ctx, tracer, "GetGorm")
	defer span.End()

	utils.HandleEvent(span, localLogger, "Retrieving GORM client")

	if client == nil {
		return nil, utils.HandleError(ctx, span, localLogger, &otterError.Database{Reason: otterError.DatabaseIsNotConnected})
	}

	utils.HandleEvent(span, localLogger, "GORM client retrieved successfully")
	return client, nil
}