package db

import (
	"errors"
	"fmt"
	"math"
	"net/http"
	"reflect"
	"strconv"
	"strings"

	"git.clearsky.net.au/cody/gex.git/sec"
)

type Pagination struct {
	PrevPage  string
	NextPage  string
	Page      int
	Pages     int
	PerPage   int
	Order     string
	Direction string
	Search    string
	Start     int
}

type Query struct {
	targetInt interface{}
	targetPtr reflect.Value
	targetVal reflect.Value
	modelType reflect.Type

	tblName string
	pkName  string
	Sess    sec.Sess
	err     error
	ready   bool

	sel   string
	where string
	order string
	vals  []any
}

func (q *Query) New(targetInt interface{}, sess sec.Sess) *Query {
	q.targetInt = targetInt
	q.targetPtr = reflect.ValueOf(q.targetInt)

	if q.targetPtr.Kind().String() != "ptr" {
		q.err = errors.New("ERROR: db.Query.New(), targetInt must be a pointer")
		return q
	}

	q.targetVal = q.targetPtr.Elem()
	q.sel = "*"

	// Get the session
	q.Sess = sess

	if q.targetVal.Kind().String() == "slice" {
		q.newSlice()
		return q
	}

	//Get the type of the model
	q.modelType = q.targetVal.Type()

	// Get the table name
	tblMth := q.targetPtr.MethodByName("Table")
	if !tblMth.IsValid() {
		q.err = errors.New("ERROR: db.Query.New(), target Table() method must be defined")
		return q
	}
	q.tblName = tblMth.Call(nil)[0].String()

	// Get the primary key name
	pkMth := q.targetPtr.MethodByName("PK")
	if !tblMth.IsValid() {
		q.err = errors.New("ERROR: db.Query.New(), target PK() method must be defined")
		return q
	}
	q.pkName = pkMth.Call(nil)[0].String()

	q.ready = true
	return q
}

func (q *Query) newSlice() {
	// Get the type of the model
	q.modelType = q.targetVal.Type().Elem()

	// create a new model so we can run the table and pk methods
	tmpModel := reflect.New(q.modelType)

	// Get the table name
	tblMth := tmpModel.MethodByName("Table")
	if !tblMth.IsValid() {
		q.err = errors.New("ERROR: db.Query.New(), target Table() method must be defined")
	}
	q.tblName = tblMth.Call(nil)[0].String()

	// Get the primary key name
	pkMth := tmpModel.MethodByName("PK")
	if !tblMth.IsValid() {
		q.err = errors.New("ERROR: db.Query.New(), target PK() method must be defined")
	}
	q.pkName = pkMth.Call(nil)[0].String()
	q.ready = true
}

func (q *Query) Reset() {
	q.sel = "*"
	q.where = ""

	var new []any
	q.vals = new
}

func (q *Query) Select(s string) *Query {
	if q.err != nil {
		return q
	}

	if !q.ready {
		q.err = errors.New("ERROR: db.Query.Select(), db.Query.New() needs to be ran first")
		return q
	}

	q.sel = s
	return q
}

func (q *Query) Where(str string, vals ...any) *Query {
	if q.err != nil {
		return q
	}

	if !q.ready {
		q.err = errors.New("ERROR: db.Query.Where(), db.Query.New() needs to run first")
		return q
	}

	q.where = fmt.Sprintf("WHERE (%s) ", str)
	q.vals = append(q.vals, vals...)
	return q
}

// Security check here to ensure str is a field (column)
func (q *Query) Order(str string) *Query {
	q.order += "ORDER BY " + str
	return q
}

func (q *Query) Create() (int64, error) {
	if q.err != nil {
		return 0, q.err
	}
	if !q.ready {
		q.err = errors.New("ERROR: db.Query.Create(), db.Query.New() needs to run first")
		return 0, q.err
	}

	if q.targetVal.Kind().String() != "struct" {
		return 0, errors.New("ERROR: db.Query.Create() model must be a struct (are you using a slice)")
	}

	fields, plcHdr, vals := q.getFields(q.targetPtr.Interface())

	for i := 0; i < len(vals); i++ {
		if vals[i] == "<nil>" {
			vals[i] = nil
		}
	}

	query := fmt.Sprintf(
		"INSERT INTO %s (%s) VALUES (%s)", q.tblName, strings.Join(fields, ", "), strings.Join(plcHdr, ", "),
	)

	q.targetVal.FieldByName("Sess").Set(reflect.ValueOf(&q.Sess))
	createRuleMethod := q.targetPtr.MethodByName("CreateRule")
	createRulePassed := createRuleMethod.Call(nil)[0].Bool()

	if !createRulePassed {
		return 0, errors.New("ERROR: db.Query.Create(), create permissions not passed")
	}

	res, err := Conn.Exec(query, vals...)

	if err != nil {
		stringVals := make([]string, len(vals))
		for i, v := range vals {
			stringVals[i] = fmt.Sprint(v)
		}
		fmt.Printf("QUERY ERROR: db.Create(), Query: `%s` Values: `%s` Error: %s ", query, strings.Join(stringVals, ","), err.Error())

		return 0, err
	}

	lastId, _ := res.LastInsertId()

	q.targetVal.FieldByName(q.pkName).Set(reflect.ValueOf(int(lastId)))
	return lastId, nil
}

func (q *Query) Read(id int) error {
	if q.err != nil {
		return q.err
	}

	if !q.ready {
		q.err = errors.New("ERROR: db.Query.Read(), db.Query.New() needs to run first")
		return q.err
	}

	if q.targetVal.Kind().String() != "struct" {
		return errors.New("ERROR: db.Query.Read(), model must be a struct (are you using a slice)")
	}

	err := q.Where(q.pkName+" = ?", id).Get()
	if err != nil {
		return err
	}
	return nil
}

func (q *Query) Update() error {
	if q.err != nil {
		return q.err
	}
	if !q.ready {
		q.err = errors.New("ERROR: db.Query.Update(), db.Query.New() needs to run first")
		return q.err
	}

	if q.targetVal.Kind().String() != "struct" {
		return errors.New("ERROR: db.Query.Update() model must be a struct (are you using a slice)")
	}

	// Check the existing data from db to check rule
	id := q.targetVal.FieldByName(q.pkName)
	tmpModel := reflect.New(q.modelType)

	tmpQuery := Query{}
	q.err = tmpQuery.New(tmpModel.Interface(), q.Sess).Read(int(id.Int()))

	if q.err != nil {
		return q.err
	}

	existRuleMethod := tmpModel.MethodByName("UpdateRule")
	existRulePassed := existRuleMethod.Call(nil)[0].Bool()

	newRuleMethod := q.targetPtr.MethodByName("UpdateRule")
	newRulePassed := newRuleMethod.Call(nil)[0].Bool()

	if !existRulePassed || !newRulePassed {
		return errors.New("ERROR: db.Query.Update() ReadRule not passed)")
	}

	fields, _, vals := q.getFields(q.targetInt)

	for i := 0; i < len(fields); i++ {
		fields[i] = fields[i] + "=?"
	}

	for i := 0; i < len(vals); i++ {
		if vals[i] == "<nil>" {
			vals[i] = nil
		}
	}

	vals = append(vals, int(id.Int()))
	query := fmt.Sprintf(
		"UPDATE %s SET %s WHERE %s=?", q.tblName, strings.Join(fields, ", "), q.pkName,
	)

	_, err := Conn.Exec(query, vals...)
	if err != nil {
		fmt.Printf("--QUERY ERROR (db.Update()): `%s` %s ", query, err.Error())
		fmt.Println("\nQuery Values: ", vals)
		q.Reset()
		return err
	}

	return nil
}

func (q *Query) Delete() error {
	if q.err != nil {
		return q.err
	}
	if !q.ready {
		q.err = errors.New("db.Query.New() needs to run first")
		return q.err
	}
	if q.targetVal.Kind().String() != "struct" {
		return errors.New("db.Query.Delete() model must be a struct (are you trying a slice or array?)")
	}

	// Check the existing data from db to check rule
	id := q.targetVal.FieldByName(q.pkName)
	tmpModel := reflect.New(q.targetVal.Type())

	tmpQuery := Query{}
	tmpQuery.New(tmpModel.Interface(), q.Sess).Read(int(id.Int()))

	existRuleMethod := tmpModel.MethodByName("DeleteRule")
	existRulePassed := existRuleMethod.Call(nil)[0].Bool()

	if !existRulePassed {
		err := "Update rule failed"
		fmt.Println(err)
		return errors.New(err)
	}

	query := fmt.Sprintf("DELETE FROM %s WHERE %s = ?", q.tblName, q.pkName)

	_, err := Conn.Exec(query, int(id.Int()))

	if err != nil {
		return errors.New("db.Query.Get(), " + err.Error())
	}
	q.Reset()
	return nil
}

func (q *Query) Get() error {
	q.targetVal.FieldByName("Sess").Set(reflect.ValueOf(&q.Sess))

	// Create a temp model to store the data
	tmpModel := reflect.New(q.modelType)
	tmpModelElem := tmpModel.Elem()
	tmpModelElem.FieldByName("Sess").Set(reflect.ValueOf(&q.Sess))
	//

	query := fmt.Sprintf("SELECT %s FROM %s %s %s", q.sel, q.tblName, q.where, q.order)
	err := Conn.QueryRow(query, q.vals...).Scan(StructPointers(tmpModel.Interface())...)
	if err != nil {
		return errors.New("db.Query.Get(), " + err.Error())
	}

	readRuleMethod := tmpModel.MethodByName("ReadRule")
	readRulePassed := readRuleMethod.Call(nil)[0].Bool()

	if !readRulePassed {
		return errors.New("ERROR: db.Query.Get(), read rules not passed")
	}
	for i := 0; i < tmpModelElem.NumField(); i++ {
		q.targetVal.Field(i).Set(tmpModelElem.Field(i))
	}
	return nil
}

func (q *Query) All() error {
	query := fmt.Sprintf("SELECT %s FROM %s %s %s", q.sel, q.tblName, q.where, q.order)
	rows, err := Conn.Query(query, q.vals...)

	if err != nil {
		return err
	}

	var set []reflect.Value
	for rows.Next() {
		tmpModel := reflect.New(q.modelType)
		tmpModel.Elem().FieldByName("Sess").Set(reflect.ValueOf(&q.Sess))
		rows.Scan(StructPointers(tmpModel.Interface())...)

		readRuleMethod := tmpModel.MethodByName("ReadRule")
		readRulePassed := readRuleMethod.Call(nil)[0].Bool()

		if !readRulePassed {
			return errors.New("ERROR: db.Query.All(), read rules not passed")
		}
		set = append(set, tmpModel.Elem())
	}
	rows.Close()

	newSlice := reflect.Append(q.targetVal, set...)
	q.targetVal.Set(newSlice)
	return nil
}

func (q *Query) getFields(s interface{}) ([]string, []string, []any) {
	targetPtr := reflect.ValueOf(s)
	targetVal := targetPtr.Elem()

	numFields := targetVal.NumField()

	var fields []string
	var plcHdr []string
	var vals []any

	for i := 0; i < numFields; i++ {
		fieldName := targetVal.Type().Field(i).Name
		if fieldName == q.pkName {
			continue
		}

		fieldVal := targetVal.Field(i)

		tag := targetVal.Type().Field(i).Tag

		if tag != "" {
			continue
		}

		if fieldVal.Kind() == reflect.Struct {
			fieldsVal, plcHdrVal, valsVal := q.getFields(fieldVal.Addr().Interface())
			fields = append(fields, fieldsVal...)
			plcHdr = append(plcHdr, plcHdrVal...)
			vals = append(vals, valsVal...)
			continue
		}

		fields = append(fields, fmt.Sprintf("%v", fieldName))
		plcHdr = append(plcHdr, "?")

		vals = append(vals, fmt.Sprintf("%v", fieldVal))
	}

	return fields, plcHdr, vals
}

func (q *Query) SortParams(r *http.Request, defaults *Pagination) {
	if r.FormValue("prevPage") != "" {
		defaults.PrevPage = r.FormValue("prevPage")
	}

	if r.FormValue("nextPage") != "" {
		defaults.NextPage = r.FormValue("nextPage")
	}

	if r.FormValue("page") != "" {
		defaults.Page, _ = strconv.Atoi(r.FormValue("page"))
	}

	if r.FormValue("perPage") != "" {
		defaults.PerPage, _ = strconv.Atoi(r.FormValue("perPage"))
	}

	if r.FormValue("order") != "" {
		defaults.Order = r.FormValue("order")
	}

	if r.FormValue("direction") != "" {
		defaults.Direction = r.FormValue("direction")
	}

	defaults.Search = r.FormValue("search")

}

func (q *Query) Sort(defaults *Pagination) *Query {

	var count int

	query := fmt.Sprintf("select count(*) as count from %s %s", q.tblName, q.where)
	_ = Conn.QueryRow(query, q.vals...).Scan(&count)

	pages := math.Ceil(float64(count) / float64(defaults.PerPage))
	defaults.Pages = int(pages)

	if defaults.PrevPage != "" {
		defaults.Page--
	}

	if defaults.NextPage != "" {
		defaults.Page++
	}

	if defaults.Page <= 0 {
		defaults.Page = 1
	}

	if defaults.Page > defaults.Pages {
		defaults.Page = defaults.Pages

	}

	defaults.Start = (defaults.Page - 1) * defaults.PerPage

	if defaults.Start < 0 {
		defaults.Start = 0
	}

	q.Order(defaults.Order + " " + defaults.Direction)
	// this.limit(sort.start, sort.perPage);

	return q
}