// Copyright GoFrame Author(https://goframe.org). All Rights Reserved.
//
// This Source Code Form is subject to the terms of the MIT License.
// If a copy of the MIT was not distributed with this file,
// You can obtain one at https://github.com/gogf/gf.

// Package sqlite implements gdb.Driver, which supports operations for database SQLite.
//
// Note:
// 1. It does not support Save features.
package sqlite

import (
	"context"
	"database/sql"
	"fmt"

	_ "github.com/glebarez/go-sqlite"

	"github.com/gogf/gf/v2/database/gdb"
	"github.com/gogf/gf/v2/encoding/gurl"
	"github.com/gogf/gf/v2/errors/gcode"
	"github.com/gogf/gf/v2/errors/gerror"
	"github.com/gogf/gf/v2/os/gfile"
	"github.com/gogf/gf/v2/text/gstr"
	"github.com/gogf/gf/v2/util/gconv"
	"github.com/gogf/gf/v2/util/gutil"
)

// Driver is the driver for sqlite database.
type Driver struct {
	*gdb.Core
}

const (
	quoteChar = "`"
)

func init() {
	if err := gdb.Register(`sqlite`, New()); err != nil {
		panic(err)
	}
}

// New create and returns a driver that implements gdb.Driver, which supports operations for SQLite.
func New() gdb.Driver {
	return &Driver{}
}

// New creates and returns a database object for sqlite.
// It implements the interface of gdb.Driver for extra database driver installation.
func (d *Driver) New(core *gdb.Core, node *gdb.ConfigNode) (gdb.DB, error) {
	return &Driver{
		Core: core,
	}, nil
}

// Open creates and returns an underlying sql.DB object for sqlite.
// https://github.com/glebarez/go-sqlite
func (d *Driver) Open(config *gdb.ConfigNode) (db *sql.DB, err error) {
	var (
		source               string
		underlyingDriverName = "sqlite"
	)
	if config.Link != "" {
		// ============================================================================
		// Deprecated from v2.2.0.
		// ============================================================================
		source = config.Link
	} else {
		source = config.Name
	}
	// It searches the source file to locate its absolute path..
	if absolutePath, _ := gfile.Search(source); absolutePath != "" {
		source = absolutePath
	}

	// Multiple PRAGMAs can be specified, e.g.:
	// path/to/some.db?_pragma=busy_timeout(5000)&_pragma=journal_mode(WAL)
	if config.Extra != "" {
		var (
			options  string
			extraMap map[string]interface{}
		)
		if extraMap, err = gstr.Parse(config.Extra); err != nil {
			return nil, err
		}
		for k, v := range extraMap {
			if options != "" {
				options += "&"
			}
			options += fmt.Sprintf(`_pragma=%s(%s)`, k, gurl.Encode(gconv.String(v)))
		}
		if len(options) > 1 {
			source += "?" + options
		}
	}

	if db, err = sql.Open(underlyingDriverName, source); err != nil {
		err = gerror.WrapCodef(
			gcode.CodeDbOperationError, err,
			`sql.Open failed for driver "%s" by source "%s"`, underlyingDriverName, source,
		)
		return nil, err
	}
	return
}

// GetChars returns the security char for this type of database.
func (d *Driver) GetChars() (charLeft string, charRight string) {
	return quoteChar, quoteChar
}

// DoFilter deals with the sql string before commits it to underlying sql driver.
func (d *Driver) DoFilter(ctx context.Context, link gdb.Link, sql string, args []interface{}) (newSql string, newArgs []interface{}, err error) {
	// Special insert/ignore operation for sqlite.
	switch {
	case gstr.HasPrefix(sql, gdb.InsertOperationIgnore):
		sql = "INSERT OR IGNORE" + sql[len(gdb.InsertOperationIgnore):]

	case gstr.HasPrefix(sql, gdb.InsertOperationReplace):
		sql = "INSERT OR REPLACE" + sql[len(gdb.InsertOperationReplace):]

	default:
		if gstr.Contains(sql, gdb.InsertOnDuplicateKeyUpdate) {
			return sql, args, gerror.NewCode(
				gcode.CodeNotSupported,
				`Save operation is not supported by sqlite driver`,
			)
		}
	}
	return d.Core.DoFilter(ctx, link, sql, args)
}

// Tables retrieves and returns the tables of current schema.
// It's mainly used in cli tool chain for automatically generating the models.
func (d *Driver) Tables(ctx context.Context, schema ...string) (tables []string, err error) {
	var result gdb.Result
	link, err := d.SlaveLink(schema...)
	if err != nil {
		return nil, err
	}

	result, err = d.DoSelect(
		ctx,
		link,
		`SELECT NAME FROM SQLITE_MASTER WHERE TYPE='table' ORDER BY NAME`,
	)
	if err != nil {
		return
	}
	for _, m := range result {
		for _, v := range m {
			tables = append(tables, v.String())
		}
	}
	return
}

// TableFields retrieves and returns the fields' information of specified table of current schema.
//
// Also see DriverMysql.TableFields.
func (d *Driver) TableFields(ctx context.Context, table string, schema ...string) (fields map[string]*gdb.TableField, err error) {
	var (
		result     gdb.Result
		link       gdb.Link
		usedSchema = gutil.GetOrDefaultStr(d.GetSchema(), schema...)
	)
	if link, err = d.SlaveLink(usedSchema); err != nil {
		return nil, err
	}
	result, err = d.DoSelect(ctx, link, fmt.Sprintf(`PRAGMA TABLE_INFO(%s)`, d.QuoteWord(table)))
	if err != nil {
		return nil, err
	}
	fields = make(map[string]*gdb.TableField)
	for i, m := range result {
		mKey := ""
		if m["pk"].Bool() {
			mKey = "pri"
		}
		fields[m["name"].String()] = &gdb.TableField{
			Index:   i,
			Name:    m["name"].String(),
			Type:    m["type"].String(),
			Key:     mKey,
			Default: m["dflt_value"].Val(),
			Null:    !m["notnull"].Bool(),
		}
	}
	return fields, nil
}