//
// Copyright 2021, Sander van Harmelen
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//

package gitlab

import (
	"fmt"
	"net/http"
	"time"
)

type (
	TodosServiceInterface interface {
		ListTodos(opt *ListTodosOptions, options ...RequestOptionFunc) ([]*Todo, *Response, error)
		MarkTodoAsDone(id int, options ...RequestOptionFunc) (*Response, error)
		MarkAllTodosAsDone(options ...RequestOptionFunc) (*Response, error)
	}

	// TodosService handles communication with the todos related methods of
	// the Gitlab API.
	//
	// GitLab API docs: https://docs.gitlab.com/api/todos/
	TodosService struct {
		client *Client
	}
)

var _ TodosServiceInterface = (*TodosService)(nil)

// Todo represents a GitLab todo.
//
// GitLab API docs: https://docs.gitlab.com/api/todos/
type Todo struct {
	ID         int            `json:"id"`
	Project    *BasicProject  `json:"project"`
	Author     *BasicUser     `json:"author"`
	ActionName TodoAction     `json:"action_name"`
	TargetType TodoTargetType `json:"target_type"`
	Target     *TodoTarget    `json:"target"`
	TargetURL  string         `json:"target_url"`
	Body       string         `json:"body"`
	State      string         `json:"state"`
	CreatedAt  *time.Time     `json:"created_at"`
}

func (t Todo) String() string {
	return Stringify(t)
}

// TodoTarget represents a todo target of type Issue or MergeRequest
type TodoTarget struct {
	Assignees            []*BasicUser           `json:"assignees"`
	Assignee             *BasicUser             `json:"assignee"`
	Author               *BasicUser             `json:"author"`
	CreatedAt            *time.Time             `json:"created_at"`
	Description          string                 `json:"description"`
	Downvotes            int                    `json:"downvotes"`
	ID                   any                    `json:"id"`
	IID                  int                    `json:"iid"`
	Labels               []string               `json:"labels"`
	Milestone            *Milestone             `json:"milestone"`
	ProjectID            int                    `json:"project_id"`
	State                string                 `json:"state"`
	Subscribed           bool                   `json:"subscribed"`
	TaskCompletionStatus *TasksCompletionStatus `json:"task_completion_status"`
	Title                string                 `json:"title"`
	UpdatedAt            *time.Time             `json:"updated_at"`
	Upvotes              int                    `json:"upvotes"`
	UserNotesCount       int                    `json:"user_notes_count"`
	WebURL               string                 `json:"web_url"`

	// Only available for type Issue
	Confidential bool        `json:"confidential"`
	DueDate      string      `json:"due_date"`
	HasTasks     bool        `json:"has_tasks"`
	Links        *IssueLinks `json:"_links"`
	MovedToID    int         `json:"moved_to_id"`
	TimeStats    *TimeStats  `json:"time_stats"`
	Weight       int         `json:"weight"`

	// Only available for type MergeRequest
	MergedAt                  *time.Time   `json:"merged_at"`
	ApprovalsBeforeMerge      int          `json:"approvals_before_merge"`
	ForceRemoveSourceBranch   bool         `json:"force_remove_source_branch"`
	MergeCommitSHA            string       `json:"merge_commit_sha"`
	MergeWhenPipelineSucceeds bool         `json:"merge_when_pipeline_succeeds"`
	MergeStatus               string       `json:"merge_status"`
	Reference                 string       `json:"reference"`
	Reviewers                 []*BasicUser `json:"reviewers"`
	SHA                       string       `json:"sha"`
	ShouldRemoveSourceBranch  bool         `json:"should_remove_source_branch"`
	SourceBranch              string       `json:"source_branch"`
	SourceProjectID           int          `json:"source_project_id"`
	Squash                    bool         `json:"squash"`
	TargetBranch              string       `json:"target_branch"`
	TargetProjectID           int          `json:"target_project_id"`
	WorkInProgress            bool         `json:"work_in_progress"`

	// Only available for type DesignManagement::Design
	FileName string `json:"filename"`
	ImageURL string `json:"image_url"`
}

// ListTodosOptions represents the available ListTodos() options.
//
// GitLab API docs: https://docs.gitlab.com/api/todos/#get-a-list-of-to-do-items
type ListTodosOptions struct {
	ListOptions
	Action    *TodoAction `url:"action,omitempty" json:"action,omitempty"`
	AuthorID  *int        `url:"author_id,omitempty" json:"author_id,omitempty"`
	ProjectID *int        `url:"project_id,omitempty" json:"project_id,omitempty"`
	GroupID   *int        `url:"group_id,omitempty" json:"group_id,omitempty"`
	State     *string     `url:"state,omitempty" json:"state,omitempty"`
	Type      *string     `url:"type,omitempty" json:"type,omitempty"`
}

// ListTodos lists all todos created by authenticated user.
// When no filter is applied, it returns all pending todos for the current user.
//
// GitLab API docs:
// https://docs.gitlab.com/api/todos/#get-a-list-of-to-do-items
func (s *TodosService) ListTodos(opt *ListTodosOptions, options ...RequestOptionFunc) ([]*Todo, *Response, error) {
	req, err := s.client.NewRequest(http.MethodGet, "todos", opt, options)
	if err != nil {
		return nil, nil, err
	}

	var t []*Todo
	resp, err := s.client.Do(req, &t)
	if err != nil {
		return nil, resp, err
	}

	return t, resp, nil
}

// MarkTodoAsDone marks a single pending todo given by its ID for the current user as done.
//
// GitLab API docs: https://docs.gitlab.com/api/todos/#mark-a-to-do-item-as-done
func (s *TodosService) MarkTodoAsDone(id int, options ...RequestOptionFunc) (*Response, error) {
	u := fmt.Sprintf("todos/%d/mark_as_done", id)

	req, err := s.client.NewRequest(http.MethodPost, u, nil, options)
	if err != nil {
		return nil, err
	}

	return s.client.Do(req, nil)
}

// MarkAllTodosAsDone marks all pending todos for the current user as done.
//
// GitLab API docs: https://docs.gitlab.com/api/todos/#mark-all-to-do-items-as-done
func (s *TodosService) MarkAllTodosAsDone(options ...RequestOptionFunc) (*Response, error) {
	req, err := s.client.NewRequest(http.MethodPost, "todos/mark_as_done", nil, options)
	if err != nil {
		return nil, err
	}

	return s.client.Do(req, nil)
}
