package cmd

import (
	"flag"
	"fmt"
	"os"
	"strings"

	"git.noodles.cam/claude-skills/marketplace/cli/internal/issue"
	"git.noodles.cam/claude-skills/marketplace/cli/internal/mapping"
	"git.noodles.cam/claude-skills/marketplace/cli/internal/wire"
)

func init() {
	register(&Command{
		Name:  "comment",
		Group: GroupSync,
		Args:  "<id>",
		Short: "post or edit a comment on a synced issue",
		Long: `The target is a LOCAL ID, not a number. Which issue this is, is a fact about the
work; where it lives in the tracker is bookkeeping, and the ` + "`gitea:`" + ` handle on the
file is what turns one into the other. An ` + "`origin: local`" + ` issue cannot be
commented on at all — it is not in the tracker, so there is nothing there to
comment on; push it first.

The body comes from a file or from --body, and multi-line prose is what --file
is for. This is why comments go through the API rather than through a tracker
CLI: an entity command with an empty-looking positional opens $EDITOR, and on a
TTY that does not exist it hangs forever.

After the write the whole thread is refetched into ` + "`<id>.comments.md`" + `, so the
local copy is not stale by one comment — the one this run just made.

COMMENTS ARE PULL-ONLY IN THE STORE. Nothing round-trips them back: editing
` + "`<id>.comments.md`" + ` by hand changes nothing in the tracker. Use --edit with a
comment id for that.`,
		Examples: []Example{
			{"kettle comment wire-sqlc-appclick --file notes.md", "post the contents of a file"},
			{`kettle comment wire-sqlc-appclick --body "готово, задеплоено"`, "post one line"},
			{"kettle comment wire-sqlc-appclick --file fix.md --edit 1234", "rewrite comment 1234 instead"},
		},
		Setup: func(fs *flag.FlagSet) func([]string) error {
			file := fs.String("file", "", "markdown file holding the comment body")
			body := fs.String("body", "", "comment body inline (short, single-line)")
			edit := fs.Int64("edit", 0, "comment id to rewrite, instead of posting a new one")
			out := storeFlag(fs)

			return func(args []string) error {
				if len(args) != 1 {
					return Fail("give exactly one issue id")
				}
				id := args[0]
				withFile, withBody := wasSet(fs, "file"), wasSet(fs, "body")
				switch {
				case withFile && withBody:
					return Fail("--file and --body are mutually exclusive")
				case !withFile && !withBody:
					return Fail("give the comment body: --file <path>, or --body \"…\"")
				}

				root, client, err := syncStartExisting(*out)
				if err != nil {
					return err
				}
				i, err := issue.Load(root, id)
				if err != nil {
					return Fail("no issue %q in %s", id, root)
				}
				key, ok := mapping.RemoteKeyOf(i)
				if !ok {
					return Fail("%s is local-only (origin: %s, no usable `%s:` handle) — "+
						"there is nothing in the tracker to comment on; `kettle push %s` first",
						id, i.Origin, mapping.GiteaKey, id)
				}
				text, err := commentBodyFrom(*file, *body)
				if err != nil {
					return err
				}

				// The handle names the repository, so a comment lands where the
				// issue actually is — even when the store has ever pointed at two.
				client = client.For(key.Repo)

				var got *wire.Comment
				verb := "posted"
				if *edit != 0 {
					verb = "edited"
					got, err = client.EditComment(*edit, text, fmt.Sprintf("comment-%d", *edit))
				} else {
					got, err = client.CreateComment(key.Number, text, "comment-"+id)
				}
				if err != nil {
					return err
				}
				// A 2xx that carries no id is not a comment. Nothing local has been
				// written yet, and nothing will be if the answer is that shape.
				if got.ID == 0 {
					return Fail("the %s answer carries no comment id — nothing local was changed", verb)
				}
				fmt.Printf("%s comment %d on %s (%s)  %s\n", verb, got.ID, id, key, got.HTMLURL)

				comments, err := client.ListComments(key.Number)
				if err != nil {
					return Fail("the comment went up, but refetching the thread failed: %v — "+
						"`kettle pull %d` to refresh the local copy", err, key.Number)
				}
				path := commentsSidecarPath(root, id)
				if len(comments) == 0 {
					// Only reachable when the thread was emptied elsewhere between
					// the write and the read. A stale sidecar for a thread that no
					// longer exists is worse than no sidecar.
					if err := os.Remove(path); err != nil && !os.IsNotExist(err) {
						return err
					}
					fmt.Printf("thread: none — %s removed\n", path)
					return nil
				}
				if err := os.WriteFile(path, []byte(mapping.RenderComments(comments)), 0o644); err != nil {
					return err
				}
				fmt.Printf("thread: %s (%d comment(s))\n", path, len(comments))
				return nil
			}
		},
	})
}

// commentBodyFrom reads the comment body from a file or takes it as given.
//
// Trimmed and then required to be non-empty: a file of whitespace is somebody
// pointing at the wrong path, and posting it would leave an empty comment in a
// thread that nobody can delete from here.
func commentBodyFrom(file, inline string) (string, error) {
	if file != "" {
		raw, err := os.ReadFile(file)
		if err != nil {
			return "", Fail("cannot read the comment body: %v", err)
		}
		inline = string(raw)
	}
	text := strings.TrimSpace(inline)
	if text == "" {
		return "", Fail("the comment body is empty — nothing was posted")
	}
	return text, nil
}