package schema

import (
	"fmt"
	"time"
)

// 对应 sqlite 中存储的 tableinfo 内部结构
const TableInfoVersion = "1.0"

// 表定义信息
type TableDefine struct {
	TableName string
	Fields    Fields
	Indexes   map[string][]string
	Ttl       time.Duration
}

// 表结构信息，对表定义信息的扩展
type TableInfo struct {
	*TableDefine
	MapNameFields map[string]*Field
	FieldNames    []string
	FieldTypes    []string
	DefValues     []any
	PartKeys      []string
	IDKeys        []string
	LatField      string
	TableIndexes  map[string][]string
	Version       string
}

func (me *TableDefine) TableInfo() (tableinfo *TableInfo, createfieldtypes []string) {
	fields := me.Fields
	tableinfo = &TableInfo{
		TableDefine:   me,
		MapNameFields: map[string]*Field{},
		FieldNames:    []string{},
		FieldTypes:    []string{},
		DefValues:     []any{},
		PartKeys:      []string{},
		IDKeys:        []string{},
		TableIndexes:  map[string][]string{},
		LatField:      "",
		Version:       TableInfoVersion,
	}
	for k, v := range me.Indexes {
		// 用户定义索引，i_ 开头
		tableinfo.TableIndexes["i_"+k] = v
	}
	for _, field := range fields {
		tableinfo.MapNameFields[field.Name] = field
		if me.Indexes == nil {
			// 未指定索引，自动生成全字段索引，i_ 开头
			// 指定空map，不建索引
			tableinfo.TableIndexes["i_"+me.TableName+"_"+field.Name] = []string{field.Name}
		}
	}
	for i := 0; ; i++ {
		tableinfo.LatField = fmt.Sprint("_last_access_time_", i)
		if tableinfo.MapNameFields[tableinfo.LatField] == nil {
			last_access_time_field := &Field{
				Name:   tableinfo.LatField,
				Type:   "int",
				Defval: time.Now().UnixNano(),
			}
			tableinfo.MapNameFields[tableinfo.LatField] = last_access_time_field
			fields = append(fields, last_access_time_field)
			// 内置索引，ii_ 开头，区别于用户定义索引
			tableinfo.TableIndexes["ii_"+me.TableName+"_"+tableinfo.LatField] = []string{tableinfo.LatField}
			break
		}
	}
	for _, field := range fields {
		tableinfo.FieldNames = append(tableinfo.FieldNames, field.Name)
		tableinfo.FieldTypes = append(tableinfo.FieldTypes, field.Type)
		createfieldtypes = append(createfieldtypes, `"`+field.Name+`" `+field.Type)
		if field.Defval == nil {
			tableinfo.DefValues = append(tableinfo.DefValues, DefaultValue(field.Type))
		} else {
			tableinfo.DefValues = append(tableinfo.DefValues, field.Defval)
		}
		if field.Partkeyi != 0 {
			for field.Partkeyi > len(tableinfo.PartKeys) {
				tableinfo.PartKeys = append(tableinfo.PartKeys, "")
			}
			tableinfo.PartKeys[field.Partkeyi-1] = field.Name
		}
		if field.Idkeyi != 0 {
			for field.Idkeyi > len(tableinfo.IDKeys) {
				tableinfo.IDKeys = append(tableinfo.IDKeys, "")
			}
			tableinfo.IDKeys[field.Idkeyi-1] = field.Name
		}
	}
	return
}