package webutility

import (
	"database/sql"
	"fmt"
)

type ListOptions struct {
	GlobalFilter  bool   `json:"globalFilter"`
	LocalFilters  bool   `json:"localFilters"`
	RemoteFilters bool   `json:"remoteFilters"`
	Pagination    bool   `json:"pagination"`
	PageSize      uint32 `json:"pageSize"`
	Pivot         bool   `json:"pivot"`
	Detail        bool   `json:"detail"`
	Total         bool   `json:"total"`
}

type ListFilter struct {
	Position       uint32   `json:"-"`
	ObjectType     string   `json:"-"`
	FiltersField   string   `json:"filtersField"`
	DefaultValues  string   `json:"defaultValues"`
	FiltersType    string   `json:"filtersType"`
	FiltersLabel   string   `json:"filtersLabel"`
	DropdownConfig Dropdown `json:"dropdownConfig"`
}

type Dropdown struct {
	ObjectType   string `json:"objectType"`
	FiltersField string `json:"filtersField"`
	IDField      string `json:"idField"`
	LabelField   string `json:"labelField"`
}

type ListGraph struct {
	ObjectType string `json:"objectType"`
	X          string `json:"xField"`
	Y          string `json:"yField"`
	GroupField string `json:"groupField"`
	Label      string `json:"label"`
}

type ListActions struct {
	Create bool `json:"create"`
	Update bool `json:"update"`
	Delete bool `json:"delete"`
	Export bool `json:"export"`
	Print  bool `json:"print"`
	Graph  bool `json:"graph"`
}

type ListNavNode struct {
	ObjectType        string `json:"objectType"`
	LabelField        string `json:"label"`
	Icon              string `json:"icon"`
	ParentObjectType  string `json:"parentObjectType"`
	ParentIDField     string `json:"parentIdField"`
	ParentFilterField string `json:"parentFilterField"`
}

type ListParentNode struct {
	ObjectType  string `json:"objectType"`
	LabelField  string `json:"labelField"`
	FilterField string `json:"filterField"`
}

type ListPivot struct {
	ObjectType    string `json:"objectType"`
	GroupField    string `json:"groupField"`
	DistinctField string `json:"distinctField"`
	Value         string `json:"valueField"`
}

type ListDetails struct {
	ObjectType        string `json:"objectType"`
	ParentObjectType  string `json:"parentObjectType"`
	ParentFilterField string `json:"parentFilterField"`
	SingleDetail      bool   `json:"singleDetail"`
}

type ListConfig struct {
	ObjectType string           `json:"objectType"`
	Title      string           `json:"title"`
	LazyLoad   bool             `json:"lazyLoad"`
	InlineEdit bool             `json:"inlineEdit"`
	Options    ListOptions      `json:"options"`
	Filters    []ListFilter     `json:"defaultFilters"`
	Graphs     []ListGraph      `json:"graphs"`
	Actions    ListActions      `json:"actions"`
	Parent     []ListParentNode `json:"parent"`
	Navigation []ListNavNode    `json:"navigation"`
	Pivots     []ListPivot      `json:"pivots"`
	Details    ListDetails      `json:"details"`
}

// GetListConfig returns list configuration for the provided object type for the front-end application
// or an error if it fails.
func GetListConfig(db *sql.DB, objType string) (ListConfig, error) {
	resp := newDefaultList(objType)
	var err error

	err = setListParams(db, &resp, objType)
	resp.Navigation, err = getListNavigation(db, objType)
	resp.Actions, err = getListActions(db, objType)
	resp.Filters, err = getListFilters(db, objType)
	resp.Options, err = getListOptions(db, objType)
	resp.Parent, err = getListParent(db, objType)
	resp.Graphs, err = getListGraph(db, objType)
	resp.Pivots, err = getListPivot(db, objType)
	resp.Details, err = getListDetails(db, objType)

	if err != nil {
		return ListConfig{}, err
	}

	return resp, nil
}

// GetListConfigObjectIDField takes in database connection and an object type and it returns the
// ID field name for the provided object type.
func GetListConfigObjectIDField(db *sql.DB, otype string) string {
	var resp string

	rows, err := db.Query(`SELECT
		ID_FIELD
		FROM LIST_CONFIG_ID_FIELD
		WHERE OBJECT_TYPE = ` + fmt.Sprintf("'%s'", otype))
	if err != nil {
		return ""
	}
	defer rows.Close()

	if rows.Next() {
		rows.Scan(&resp)
	}

	if rows.Err() != nil {
		return ""
	}

	return resp
}

// newDefaultList returns default configuration for the provided object type.
func newDefaultList(objType string) ListConfig {
	list := ListConfig{
		ObjectType: objType,
		Title:      objType,
		LazyLoad:   false,
		Options: ListOptions{
			GlobalFilter:  true,
			LocalFilters:  true,
			RemoteFilters: false,
			Pagination:    true,
			PageSize:      20,
		},
		Filters: nil,
		Actions: ListActions{
			Create: false,
			Update: false,
			Delete: false,
			Export: false,
			Print:  false,
			Graph:  false,
		},
		Parent:     nil,
		Navigation: nil,
	}

	return list
}

// setListParams sets the default parameters of the provided configuration list for the provided object type.
func setListParams(db *sql.DB, list *ListConfig, objType string) error {
	rows, err := db.Query(`SELECT
		OBJECT_TYPE, TITLE, LAZY_LOAD, INLINE_EDIT
		FROM LIST_CONFIG
		WHERE OBJECT_TYPE = ` + fmt.Sprintf("'%s'", objType))
	if err != nil {
		return err
	}
	defer rows.Close()
	if rows.Next() {
		otype, title := "", ""
		lazyLoad, inlineEdit := 0, 0
		rows.Scan(&otype, &title, &lazyLoad, &inlineEdit)

		if otype != "" {
			list.ObjectType = otype
		}
		if title != "" {
			list.Title = title
		}
		list.LazyLoad = lazyLoad != 0
		list.InlineEdit = inlineEdit != 0
	}
	if rows.Err() != nil {
		return rows.Err()
	}
	return nil
}

// getListNavigation returns list navigation node slice for the provided objectType.
func getListNavigation(db *sql.DB, listObjType string) ([]ListNavNode, error) {
	resp := make([]ListNavNode, 0)
	rows, err := db.Query(`SELECT
		a.OBJECT_TYPE, a.PARENT_OBJECT_TYPE, a.LABEL, a.ICON, a.PARENT_FILTER_FIELD, b.PARENT_ID_FIELD
		FROM LIST_CONFIG_NAVIGATION b
		JOIN LIST_CONFIG_CHILD a ON b.PARENT_CHILD_ID = a.PARENT_CHILD_ID
		WHERE b.LIST_OBJECT_TYPE = ` + fmt.Sprintf("'%s'", listObjType) +
		` ORDER BY b.RB ASC`)
	if err != nil {
		return resp, err
	}
	defer rows.Close()

	var node ListNavNode
	for rows.Next() {
		rows.Scan(&node.ObjectType, &node.ParentObjectType, &node.LabelField, &node.Icon,
			&node.ParentFilterField, &node.ParentIDField)
		resp = append(resp, node)
	}
	if rows.Err() != nil {
		return nil, rows.Err()
	}

	return resp, nil
}

// getListActions returns list actions for the provided object type.
func getListActions(db *sql.DB, objType string) (ListActions, error) {
	var resp ListActions
	rows, err := db.Query(`SELECT
		ACTION_CREATE, ACTION_UPDATE, ACTION_DELETE, ACTION_EXPORT,
		ACTION_PRINT, ACTION_GRAPH
		FROM LIST_CONFIG
		WHERE OBJECT_TYPE = ` + fmt.Sprintf("'%s'", objType))
	if err != nil {
		return ListActions{}, err
	}
	defer rows.Close()

	var create, update, delete, export, print, graph uint32
	if rows.Next() {
		rows.Scan(&create, &update, &delete, &export, &print, &graph)
		resp.Create = create != 0
		resp.Update = update != 0
		resp.Delete = delete != 0
		resp.Export = export != 0
		resp.Print = print != 0
		resp.Graph = graph != 0
	}
	if rows.Err() != nil {
		return ListActions{}, rows.Err()
	}
	return resp, nil
}

// getListFiters returns list filter slice for the provided object type.
func getListFilters(db *sql.DB, objType string) ([]ListFilter, error) {
	resp := make([]ListFilter, 0)
	filtersFields, err := getFilterFieldsAndPosition(db, objType)
	if err != nil {
		return nil, err
	}
	for field, pos := range filtersFields {
		filters, _ := getFiltersByFilterField(db, field)
		for _, filter := range filters {
			var f ListFilter
			f.Position = pos
			f.ObjectType = objType
			f.FiltersField = field
			f.DefaultValues = filter.DefaultValues
			f.FiltersLabel = filter.Label
			f.FiltersType = filter.Type
			if filter.Type == "dropdown" {
				f.DropdownConfig, err = getFilterDropdownConfig(db, field)
				if err != nil {
					return nil, err
				}
			}
			resp = append(resp, f)
		}
	}

	sortFilters(resp)

	return resp, nil
}

// getFilterFieldsAndPosition returns a map of filter fields and their respective position in the menu.
func getFilterFieldsAndPosition(db *sql.DB, objType string) (map[string]uint32, error) {
	filtersField := make(map[string]uint32, 0)
	rows, err := db.Query(`SELECT
		FILTERS_FIELD, RB
		FROM LIST_CONFIG_FILTERS
		WHERE OBJECT_TYPE = ` + fmt.Sprintf("'%s'", objType))
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	for rows.Next() {
		var field string
		var rb uint32
		rows.Scan(&field, &rb)
		filtersField[field] = rb
	}
	if rows.Err() != nil {
		return nil, rows.Err()
	}
	return filtersField, nil
}

type _filter struct {
	DefaultValues string
	Label         string
	Type          string
}

// getFiltersByFilterField returns filter slice for the provided filter field.
func getFiltersByFilterField(db *sql.DB, filtersField string) ([]_filter, error) {
	resp := make([]_filter, 0)
	rows, err := db.Query(`SELECT
		FILTERS_TYPE, FILTERS_LABEL, DEFAULT_VALUES
		FROM LIST_FILTERS_FIELD
		WHERE FILTERS_FIELD = ` + fmt.Sprintf("'%s'", filtersField))
	if err != nil {
		return resp, err
	}
	defer rows.Close()

	var f _filter
	for rows.Next() {
		rows.Scan(&f.Type, &f.Label, &f.DefaultValues)
		resp = append(resp, f)
	}
	if rows.Err() != nil {
		return resp, rows.Err()
	}
	return resp, nil
}

// getFilterDropdownConfig returns dropdown menu for the provided filter field.
func getFilterDropdownConfig(db *sql.DB, filtersField string) (Dropdown, error) {
	var resp Dropdown
	rows, err := db.Query(`SELECT
		FILTERS_FIELD, OBJECT_TYPE, ID_FIELD, LABEL_FIELD
		FROM LIST_DROPDOWN_FILTER
		WHERE FILTERS_FIELD = ` + fmt.Sprintf("'%s'", filtersField))
	if err != nil {
		return resp, err
	}
	defer rows.Close()
	if rows.Next() {
		rows.Scan(&resp.FiltersField, &resp.ObjectType, &resp.IDField, &resp.LabelField)
	}
	if rows.Err() != nil {
		return resp, rows.Err()
	}
	return resp, nil
}

// sortFilters bubble sorts provided filters slice by position field.
func sortFilters(filters []ListFilter) {
	done := false
	var temp ListFilter
	for !done {
		done = true
		for i := 0; i < len(filters)-1; i++ {
			if filters[i].Position > filters[i+1].Position {
				done = false
				temp = filters[i]
				filters[i] = filters[i+1]
				filters[i+1] = temp
			}
		}
	}
}

// getListGraph return list graph slice for the provided object type.
func getListGraph(db *sql.DB, objType string) ([]ListGraph, error) {
	resp := make([]ListGraph, 0)
	rows, err := db.Query(`SELECT
		OBJECT_TYPE, X_FIELD, Y_FIELD, GROUP_FIELD, LABEL
		FROM LIST_GRAPHS
		WHERE OBJECT_TYPE = ` + fmt.Sprintf("'%s'", objType))
	if err != nil {
		return resp, err
	}
	defer rows.Close()

	var lg ListGraph
	for rows.Next() {
		rows.Scan(&lg.ObjectType, &lg.X, &lg.Y, &lg.GroupField, &lg.Label)
		resp = append(resp, lg)
	}
	if rows.Err() != nil {
		return resp, rows.Err()
	}
	return resp, nil
}

// getListOptions returns list options for the provided object type.
func getListOptions(db *sql.DB, objType string) (ListOptions, error) {
	var resp ListOptions
	rows, err := db.Query(`SELECT
		GLOBAL_FILTER, LOCAL_FILTER, REMOTE_FILTER, PAGINATION,
		PAGE_SIZE, PIVOT, DETAIL, TOTAL
		FROM LIST_CONFIG
		WHERE OBJECT_TYPE = ` + fmt.Sprintf("'%s'", objType))
	if err != nil {
		return ListOptions{}, err
	}
	defer rows.Close()
	if rows.Next() {
		var gfilter, lfilters, rfilters, pagination, pageSize, pivot, detail, total uint32
		rows.Scan(&gfilter, &lfilters, &rfilters, &pagination, &pageSize, &pivot, &detail, &total)
		resp.GlobalFilter = gfilter != 0
		resp.LocalFilters = lfilters != 0
		resp.RemoteFilters = rfilters != 0
		resp.Pagination = pagination != 0
		resp.PageSize = pageSize
		resp.Pivot = pivot != 0
		resp.Detail = detail != 0
		resp.Total = total != 0
	}
	if rows.Err() != nil {
		return ListOptions{}, rows.Err()
	}
	return resp, nil
}

// getListParent returns list parent node slice for the provided object type.
func getListParent(db *sql.DB, objType string) ([]ListParentNode, error) {
	resp := make([]ListParentNode, 0)
	rows, err := db.Query(`SELECT
		PARENT_OBJECT_TYPE, PARENT_LABEL_FIELD, PARENT_FILTER_FIELD
		FROM LIST_CONFIG_CHILD
		WHERE OBJECT_TYPE = ` + fmt.Sprintf("'%s'", objType))
	if err != nil {
		return resp, err
	}
	defer rows.Close()

	var pnode ListParentNode
	for rows.Next() {
		rows.Scan(&pnode.ObjectType, &pnode.LabelField, &pnode.FilterField)
		resp = append(resp, pnode)
	}
	if rows.Err() != nil {
		return nil, rows.Err()
	}

	return resp, nil
}

// getListPivot list pivot slice for the provided object type.
func getListPivot(db *sql.DB, objType string) ([]ListPivot, error) {
	resp := make([]ListPivot, 0)
	rows, err := db.Query(`SELECT
		OBJECT_TYPE, GROUP_FIELD, DISTINCT_FIELD, VALUE_FIELD
		FROM LIST_PIVOTS
		WHERE OBJECT_TYPE = ` + fmt.Sprintf("'%s'", objType))
	if err != nil {
		return resp, err
	}
	defer rows.Close()

	var p ListPivot
	for rows.Next() {
		rows.Scan(&p.ObjectType, &p.GroupField, &p.DistinctField, &p.Value)
		resp = append(resp, p)
	}
	if rows.Err() != nil {
		return nil, rows.Err()
	}

	return resp, nil
}

// getListDetails returns list details for the provided object type.
func getListDetails(db *sql.DB, objType string) (ListDetails, error) {
	var resp ListDetails
	rows, err := db.Query(`SELECT
		OBJECT_TYPE, PARENT_OBJECT_TYPE, PARENT_FILTER_FIELD, SINGLE_DETAIL
		FROM LIST_CONFIG_DETAIL
		WHERE PARENT_OBJECT_TYPE = ` + fmt.Sprintf("'%s'", objType))
	if err != nil {
		return resp, err
	}
	defer rows.Close()
	if rows.Next() {
		var singleDetail uint32
		rows.Scan(&resp.ObjectType, &resp.ParentObjectType, &resp.ParentFilterField, &singleDetail)
		resp.SingleDetail = singleDetail != 0
	}
	if rows.Err() != nil {
		return resp, rows.Err()
	}

	return resp, nil
}