// Copyright 2026 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT

package app

import (
	"errors"
	"strconv"
	"strings"
	"time"

	"gitea.dev/tea/internal/clierr"
	"gitea.dev/tea/internal/services"
	"gitea.dev/tea/internal/terminal"
	"github.com/spf13/cobra"
)

func (a *application) milestoneCommand() *cobra.Command {
	group := &cobra.Command{Use: "milestone", Short: "Manage repository milestones"}
	service := func(cmd *cobra.Command) (services.Milestones, error) {
		t, err := a.resolve(cmd.Context(), true)
		return services.Milestones{Client: t.client, Repository: t.Repo}, err
	}
	var limit, page int
	var state string
	list := &cobra.Command{Use: "list", Short: "List milestones", Args: argsExact(0), RunE: func(cmd *cobra.Command, _ []string) error {
		if err := oneOf("state", state, "open", "closed", "all"); err != nil {
			return err
		}
		s, err := service(cmd)
		if err != nil {
			return err
		}
		items, err := s.List(cmd.Context(), state, limit, page)
		if err != nil {
			return err
		}
		return writeList(a, cmd, items, milestoneRow)
	}}
	pageFlags(list, &limit, &page)
	list.Flags().StringVar(&state, "state", "open", "open, closed, all")
	group.AddCommand(list)
	for _, verb := range []string{"view", "create", "edit", "delete"} {
		var title, description, descriptionFile, deadline, createState string
		var byName, useEditor bool
		command := &cobra.Command{Use: verb, Short: titleCase(verb) + " a milestone"}
		if verb == "create" {
			command.Args = argsExact(0)
		} else {
			command.Use += " <milestone>"
			command.Flags().BoolVar(&byName, "by-name", false, "Match a numeric argument as a milestone title rather than an ID")
			command.Args = argsExact(1)
		}
		if verb == "create" || verb == "edit" {
			command.Flags().StringVar(&title, "title", "", "Milestone title")
			command.Flags().StringVar(&description, "description", "", "Milestone description")
			command.Flags().StringVar(&descriptionFile, "description-file", "", "Read description from file, or - for stdin")
			command.Flags().BoolVar(&useEditor, "editor", false, "Edit the milestone description in the configured editor")
			command.Flags().StringVar(&deadline, "deadline", "", "Due date: YYYY-MM-DD, RFC3339, or Unix timestamp; empty clears")
		}
		if verb == "create" {
			command.Flags().StringVar(&createState, "state", "open", "Milestone state: open or closed")
		}
		command.RunE = func(cmd *cobra.Command, args []string) (runErr error) {
			var editorDraft terminal.Draft
			defer finishDraft(&editorDraft, &runErr)
			if verb == "create" || verb == "edit" {
				if err := validateTextSources(cmd, "description", "description-file"); err != nil {
					return err
				}
			}
			opts := services.MilestoneOptions{}
			if verb != "create" && strings.TrimSpace(args[0]) == "" {
				return clierr.Wrap(clierr.Usage, errors.New("milestone title or ID cannot be empty"))
			}
			var interactiveDeadline *time.Time
			descriptionChanged := false
			if verb == "create" {
				if err := oneOf("state", createState, "open", "closed"); err != nil {
					return err
				}
				opts.State = &createState
				snapshot, err := a.deps.Settings.Load()
				if err != nil {
					return err
				}
				policy := a.policy(snapshot)
				if !localFlagsChanged(cmd) && policy.CanPrompt(a.deps.Streams) && a.deps.MilestoneForm != nil {
					values, err := a.deps.MilestoneForm.CreateMilestone(cmd.Context())
					if err != nil {
						return err
					}
					title, description = values.Title, values.Description
					interactiveDeadline = values.Deadline
					descriptionChanged = true
				} else if _, err := a.require(cmd, &title, "title"); err != nil {
					return err
				}
			}
			if (verb == "create" || verb == "edit") && !useEditor {
				var err error
				description, err = a.readTextSource(cmd, description, descriptionFile, "description", "description-file")
				if err != nil {
					return err
				}
				if cmd.Flags().Changed("description") || cmd.Flags().Changed("description-file") {
					descriptionChanged = true
				}
			}
			if cmd.Flags().Changed("title") && strings.TrimSpace(title) == "" {
				return clierr.Wrap(clierr.Usage, errors.New("milestone title cannot be empty"))
			}
			if verb == "create" || cmd.Flags().Changed("title") {
				opts.Title = &title
			}
			if cmd.Flags().Changed("deadline") || interactiveDeadline != nil {
				date := time.Time{}
				if interactiveDeadline != nil {
					date = *interactiveDeadline
				} else if deadline != "" {
					parsed, _, err := parseDeadline(deadline)
					if err != nil {
						return err
					}
					date = *parsed
				}
				normalized := date.Format(time.RFC3339)
				opts.Deadline = &normalized
			}

			if verb == "edit" && opts.Title == nil && !descriptionChanged && !useEditor && opts.Deadline == nil {
				return clierr.Wrap(clierr.Usage, errors.New("supply milestone fields to edit"))
			}
			s, err := service(cmd)
			if err != nil {
				return err
			}
			var current services.Milestone
			if verb != "create" {
				if current, err = s.FindOne(cmd.Context(), args[0], byName); err != nil {
					return err
				}
			}
			id := current.ID
			if verb == "delete" {
				if err := a.confirm(cmd, "Delete milestone "+args[0]); err != nil {
					return err
				}
				if err := s.Delete(cmd.Context(), id); err != nil {
					return err
				}
				if a.options.json != "" {
					return writeItem(a, cmd, current, milestoneRow)
				}
				return nil
			}
			if useEditor {
				editorDraft, err = a.editDraft(cmd, current.Description)
				if err != nil {
					return err
				}
				description = editorDraft.Body
				descriptionChanged = true
			}
			if verb == "create" || descriptionChanged {
				opts.Description = &description
			}
			var item services.Milestone
			if verb == "view" {
				item = current
			} else if verb == "create" {
				item, err = s.Create(cmd.Context(), opts)
			} else {
				item, err = s.Edit(cmd.Context(), id, opts)
			}
			if err != nil {
				return err
			}
			return writeItem(a, cmd, item, milestoneRow)
		}
		group.AddCommand(command)
	}
	group.AddCommand(a.milestoneStateCommand("close", service), a.milestoneStateCommand("reopen", service))
	group.AddCommand(a.milestoneIssueCommand())
	return group
}

func milestoneRow(item services.Milestone) []terminal.Cell {
	return []terminal.Cell{{Text: strconv.FormatInt(item.ID, 10)}, {Text: item.Title}, {Text: item.State, Color: stateColors[item.State]}}
}