// Copyright 2024 Patial Tech. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package db

import (
	"context"
	"database/sql"
	"database/sql/driver"
	"time"

	"contrib.go.opencensus.io/integrations/ocsql"
	"entgo.io/ent/dialect"
	entsql "entgo.io/ent/dialect/sql"
	pgx "github.com/jackc/pgx/v5/stdlib"
	"gitserver.in/patialtech/rano/config"
	"gitserver.in/patialtech/rano/db/ent"
	"gitserver.in/patialtech/rano/util/logger"
)

type connector struct {
	dsn string
}

// New *sql.DB instance
func New() *sql.DB {
	databaseUrl := config.Read().DbURL
	db := sql.OpenDB(connector{dsn: databaseUrl})
	db.SetMaxOpenConns(50)
	db.SetMaxIdleConns(5)
	db.SetConnMaxLifetime(0) // Maximum amount of time a connection can be reused (0 means no limit)
	return db
}

func (c connector) Connect(context.Context) (driver.Conn, error) {
	return c.Driver().Open(c.dsn)
}

func (connector) Driver() driver.Driver {
	return ocsql.Wrap(
		pgx.GetDefaultDriver(),
		ocsql.WithAllTraceOptions(),
		ocsql.WithRowsClose(false),
		ocsql.WithRowsNext(false),
		ocsql.WithDisableErrSkip(true),
	)
}

// Client for pgx
//
// https://entgo.io/docs/sql-integration
func Client() *ent.Client {
	// Create an ent.Driver from `db`.
	drv := entsql.OpenDB(dialect.Postgres, New())
	cl := ent.NewClient(ent.Driver(drv))
	cl.Use(AuditHook)
	return cl
}

type entity interface {
	GetID() (int64, error)
}

// A AuditHook is an example for audit-log hook.
func AuditHook(next ent.Mutator) ent.Mutator {
	return ent.MutateFunc(func(ctx context.Context, m ent.Mutation) (v ent.Value, err error) {
		start := time.Now()
		defer func() {
			saveAudit(ctx, m.Type(), m.Op(), v, err, time.Since(start))
		}()

		v, err = next.Mutate(ctx, m)
		return
	})
}

func saveAudit(ctx context.Context, t string, op ent.Op, v ent.Value, err error, d time.Duration) {
	if t == "Audit" {
		// skip Audit table operations
		return
	}

	var entOp string
	switch {
	case op.Is(ent.OpCreate):
		entOp = "Create"
	case op.Is(ent.OpDelete):
		entOp = "Delete"
	case op.Is(ent.OpDeleteOne):
		entOp = "DeleteOne"
	case op.Is(ent.OpUpdate):
		entOp = "Update"
	case op.Is(ent.OpUpdateOne):
		entOp = "UpdateOne"
	}

	big.
		reqID := ctx.Value("RequestID")
	ip := ctx.Value("RequestIP")
	ua := ctx.Value("RequestUA")

	if en, ok := v.(entity); ok {
		id, _ := en.GetID()
		logger.Info("%s %s %s-%s(%d) ip=%s ua=%s t=%v error=%e", reqID, status, op.String(), t, id, ip, ua, d, err)
	} else {
		logger.Info("%s %s %s-%s ip=%s ua=%s t=%v error=%e", reqID, status, op.String(), t, ip, ua, d, err)
	}
}