package scheduler

import (
	"encoding/json"
	"reflect"
	"strconv"
	"strings"
	"time"

	"git.loafle.net/commons/util-go/time/scheduler/storage"
	"git.loafle.net/commons/util-go/time/scheduler/task"
)

type storageAdapter struct {
	taskStorage        storage.TaskStorage
	taskTargetRegistry *task.TaskTargetRegistry
}

func (a *storageAdapter) Add(task *task.Task) error {
	ta, err := a.getTaskAttribute(task)
	if err != nil {
		return err
	}
	return a.taskStorage.Add(ta)
}

func (a *storageAdapter) Fetch() ([]*task.Task, error) {
	tas, err := a.taskStorage.Fetch()
	if err != nil {
		return nil, err
	}
	var tasks []*task.Task
	for _, ta := range tas {
		lastRun, err := time.Parse(time.RFC3339, ta.LastRun)
		if err != nil {
			return nil, err
		}

		nextRun, err := time.Parse(time.RFC3339, ta.NextRun)
		if err != nil {
			return nil, err
		}

		duration, err := time.ParseDuration(ta.Duration)
		if err != nil {
			return nil, err
		}

		isRecurring, err := strconv.Atoi(ta.IsRecurring)
		if err != nil {
			return nil, err
		}

		taskTarget, err := a.taskTargetRegistry.Get(ta.Name)
		if err != nil {
			return nil, err
		}

		params, err := paramsFromString(taskTarget, ta.Params)
		if err != nil {
			return nil, err
		}

		t := task.NewWithSchedule(taskTarget, params, &task.TaskSchedule{
			IsRecurring: isRecurring == 1,
			Duration:    time.Duration(duration),
			LastRun:     lastRun,
			NextRun:     nextRun,
		})
		tasks = append(tasks, t)
	}
	return tasks, nil
}

func (a *storageAdapter) Remove(task *task.Task) error {
	ta, err := a.getTaskAttribute(task)
	if err != nil {
		return err
	}
	return a.taskStorage.Remove(ta)
}

func (a *storageAdapter) getTaskAttribute(task *task.Task) (*storage.TaskAttribute, error) {
	params, err := paramsToString(task.Params)
	if err != nil {
		return nil, err
	}

	isRecurring := 0
	if task.IsRecurring {
		isRecurring = 1
	}

	return &storage.TaskAttribute{
		Hash:        string(task.Hash()),
		Name:        task.TaskTarget.Name,
		LastRun:     task.LastRun.Format(time.RFC3339),
		NextRun:     task.NextRun.Format(time.RFC3339),
		Duration:    task.Duration.String(),
		IsRecurring: strconv.Itoa(isRecurring),
		Params:      params,
	}, nil
}

func paramsToString(params []interface{}) (string, error) {
	var paramsList []string
	for _, param := range params {
		paramStr, err := json.Marshal(param)
		if err != nil {
			return "", err
		}
		paramsList = append(paramsList, string(paramStr))
	}
	data, err := json.Marshal(paramsList)
	return string(data), err
}

func paramsFromString(taskTarget *task.TaskTarget, payload string) ([]interface{}, error) {
	var params []interface{}
	if strings.TrimSpace(payload) == "" {
		return params, nil
	}
	paramTypes := taskTarget.Params()
	var paramsStrings []string
	err := json.Unmarshal([]byte(payload), &paramsStrings)
	if err != nil {
		return params, err
	}
	for i, paramStr := range paramsStrings {
		paramType := paramTypes[i]
		target := reflect.New(paramType)
		err := json.Unmarshal([]byte(paramStr), target.Interface())
		if err != nil {
			return params, err
		}
		param := reflect.Indirect(target).Interface()
		params = append(params, param)
	}

	return params, nil
}