package sqlx

import (
	"context"
	"errors"
	"fmt"
	"git.diulo.com/mogfee/kit/mapping"
	"strconv"
	"strings"
	"time"
)

var errUnbalancedEscape = errors.New("no char after escape char")

func desensitize(datasource string) string {
	pos := strings.LastIndex(datasource, "@")
	if 0 <= pos && pos+1 < len(datasource) {
		datasource = datasource[pos+1:]
	}
	return datasource
}
func escape(input string) string {
	var b strings.Builder
	for _, ch := range input {
		switch ch {
		case '\x00':
			b.WriteString(`\x00`)
		case '\r':
			b.WriteString(`\r`)
		case '\n':
			b.WriteString(`\n`)
		case '\\':
			b.WriteString(`\\`)
		case '\'':
			b.WriteString(`\'`)
		case '"':
			b.WriteString(`"`)
		case '\x1a':
			b.WriteString(`\x1a`)
		default:
			b.WriteRune(ch)
		}
	}
	return b.String()
}
func format(query string, args ...any) (string, error) {
	numArgs := len(args)
	if numArgs == 0 {
		return query, nil
	}
	var b strings.Builder
	var argIndex int
	bytes := len(query)
	for i := 0; i < bytes; i++ {
		ch := query[i]
		switch ch {
		case '?':
			if argIndex >= numArgs {
				return "", fmt.Errorf("%d ? in sql, but less arguemnt provided", argIndex)
			}
			writeValue(&b, args[argIndex])
			argIndex++
		case ':', '$':
			var j int
			for j = i + 1; j < bytes; j++ {
				char := query[j]
				if char < '0' || '9' < char {
					break
				}
			}

			if j > i+1 {
				index, err := strconv.Atoi(query[i+1 : j])
				if err != nil {
					return "", err
				}
				if index > argIndex {
					argIndex = index
				}
				index--
				if index < 0 || numArgs <= index {
					return "", fmt.Errorf("wrong index %d in sql", index)
				}
				writeValue(&b, args[index])
				i = j - 1
			}
		case '\'', '"', '`':
			b.WriteByte(ch)
			for j := i + 1; j < bytes; j++ {
				cur := query[j]
				b.WriteByte(cur)
				if cur == '\\' {
					j++
					if j >= bytes {
						return "", errUnbalancedEscape
					}
					b.WriteByte(query[j])
				} else if cur == ch {
					i = j
					break
				}
			}
		default:
			b.WriteByte(ch)
		}
	}
	if argIndex < numArgs {
		return "", fmt.Errorf("%d arguments provided, not matching sql", argIndex)
	}
	return b.String(), nil
}

func logInstanceError(ctx context.Context, datasource string, err error) {
	datasource = desensitize(datasource)
	fmt.Println(datasource, err)
	//logx.WithContext(ctx).Errorf("Error on getting sql instance of %s: %v", datasource, err)
}
func logSqlError(ctx context.Context, stmt string, err error) {
	if err != nil && err != ErrNotFound {
		fmt.Println(stmt, err)
		//logx.WithContext(ctx).Errorf("Error on getting sql instance of %s: %v", datasource, err)
	}
}
func writeValue(buf *strings.Builder, arg any) {
	switch v := arg.(type) {
	case bool:
		if v {
			buf.WriteByte('1')
		} else {
			buf.WriteByte('0')
		}
	case string:
		buf.WriteByte('\'')
		buf.WriteString(escape(v))
		buf.WriteByte('\'')
	case time.Time:
		buf.WriteByte('\'')
		buf.WriteString(v.String())
		buf.WriteByte('\'')
	case *time.Time:
		buf.WriteByte('\'')
		buf.WriteString(v.String())
		buf.WriteByte('\'')
	default:
		buf.WriteString(mapping.Repr(v))
	}
}