package ajax

import (
	"bytes"
	"encoding/gob"
	"local/todo-server/server/ajax/form"
	"local/todo-server/server/ajax/task"
	"net/http"
	"path"
	"strings"
)

func (a *Ajax) Cur(r *http.Request) (string, string, []string) {
	listID, _ := a.storageGetCur()
	taskID := form.Get(r, "id")
	tags, _ := a.storageGetCurTags()
	return listID, taskID, tags
}

func (a *Ajax) storageListTasks(listID string, filters ...func(t *task.Task) bool) ([]*task.Task, error) {
	results, err := a.DB.List(nil, listID+"/", listID+"/}")
	if err != nil {
		return nil, err
	}
	tasks := []*task.Task{}
	for _, result := range results {
		taskID := strings.TrimPrefix(result, listID+"/")
		task, err := a.storageGetTask(listID, taskID)
		if err != nil {
			return nil, err
		}
		filtered := true
		for _, f := range filters {
			if !f(task) {
				filtered = false
				break
			}
		}
		if filtered {
			tasks = append(tasks, task)
		}
	}
	return tasks, nil
}

func (a *Ajax) storageGetTask(listID, taskID string) (*task.Task, error) {
	var task task.Task
	err := a.storageGet(path.Join(listID, taskID), &task)
	return &task, err
}

func (a *Ajax) storageSetTask(listID, taskID string, newTask *task.Task) error {
	if newTask == nil {
		newTask = &task.Task{}
	}
	return a.storageSet(path.Join(listID, taskID), *newTask)
}

func (a *Ajax) storageDelTask(listID, taskID string) error {
	return a.storageDel(path.Join(listID, taskID))
}

func (a *Ajax) storageGetList(listID string) (*List, error) {
	var list List
	err := a.storageGet(listID, &list)
	return &list, err
}

func (a *Ajax) storageSetList(listID string, list *List) error {
	return a.storageSet(listID, *list)
}

func (a *Ajax) storageDelList(listID string) error {
	return a.storageDel(listID)
}

func (a *Ajax) storageSetCurTags(tags []string) error {
	return a.storageSet("currentTags", tags)
}

func (a *Ajax) storageGetCurTags() ([]string, error) {
	var tags []string
	err := a.storageGet("currentTags", &tags)
	return tags, err
}

func (a *Ajax) storageSetCur(listID string) error {
	return a.storageSet("currentList", listID)
}

func (a *Ajax) storageGetCur() (string, error) {
	var listID string
	err := a.storageGet("currentList", &listID)
	return listID, err
}

func (a *Ajax) storageSet(key string, value interface{}) error {
	buff := bytes.NewBuffer(nil)
	encoder := gob.NewEncoder(buff)
	if err := encoder.Encode(value); err != nil {
		return err
	}
	return a.DB.Set(key, buff.Bytes())
}

func (a *Ajax) storageGet(key string, value interface{}) error {
	b, err := a.DB.Get(key)
	if err != nil {
		return err
	}
	buff := bytes.NewBuffer(b)
	decoder := gob.NewDecoder(buff)
	return decoder.Decode(value)
}

func (a *Ajax) storageDel(key string) error {
	return a.DB.Set(key, nil)
}