package cmd

import (
	"flag"
	"fmt"
	"os"
	"path/filepath"
	"strings"

	"git.noodles.cam/claude-skills/marketplace/cli/internal/config"
	"git.noodles.cam/claude-skills/marketplace/cli/internal/project"
)

// writeConfig creates or updates .kettle/config.yaml, touching only the
// settings it was given.
//
// Init is idempotent, and that has to include the config: re-running it to add
// a repository must not silently drop the login somebody pinned last week.
func writeConfig(root, login, repo string, dryRun bool) (string, error) {
	path := filepath.Join(root, project.Marker, "config.yaml")
	rel := filepath.Join(project.Marker, "config.yaml")

	cfg, existed, err := config.ReadProjectFile(path)
	if err != nil {
		return "", err
	}
	changed := !existed
	if login != "" && cfg.Login != login {
		cfg.Login, changed = login, true
	}
	if repo != "" && cfg.Repo != repo {
		cfg.Repo, changed = repo, true
	}
	if !changed {
		return "", nil
	}

	verb := "updated"
	if !existed {
		verb = "created"
	}
	detail := "no login or repository pinned yet — `kettle init --login … --repo …`"
	if cfg.Login != "" || cfg.Repo != "" {
		detail = fmt.Sprintf("login: %s, repo: %s", orNone(cfg.Login), orNone(cfg.Repo))
	}
	if dryRun {
		return fmt.Sprintf("%s %s (%s)", verb, rel, detail), nil
	}
	if err := config.SaveProject(path, cfg); err != nil {
		return "", err
	}
	return fmt.Sprintf("%s %s (%s)", verb, rel, detail), nil
}

func orNone(s string) string {
	if s == "" {
		return "none"
	}
	return s
}

func init() {
	register(&Command{
		Name:  "init",
		Group: GroupProject,
		Short: "make this directory a project that tracks issues",
		Long: `Creates ` + "`.kettle/`" + ` — the marker every other command resolves the store from,
and ` + "`.kettle/config.yaml`" + `, which says which tracker repository these issues
belong to and which login to reach it under.

The marker is deliberately something an operator makes, not something inferred
from the tree: ` + "`.git`" + ` is in every clone, so anything that inferred a root from
one would write issues into whatever it happened to be installed in.

--login pins a name, never a credential. The tokens live in one file per
machine, outside every working tree, managed with ` + "`kettle auth`" + `.

All of it is idempotent: it creates .kettle/issues and .kettle/payload, migrates
an older store in if it finds one (either layout the tea plugin used, oldest
first), writes the config without disturbing settings it was not given, and adds
.kettle/ to .gitignore. Each migration is a move, not a copy — two stores is the
state the marker exists to prevent — and it refuses to pick a winner when both
sides hold a file of the same name.

Do NOT run this inside a linked worktree. A worktree is the same project on
another branch and reaches the store by a hop out to the main checkout; a marker
here would give one project two stores, and the directory holding the second one
disappears with the branch.`,
		Examples: []Example{
			{"kettle init", "initialize the current directory"},
			{"kettle init --login noodles --repo claude-skills/marketplace", "and point it at a tracker"},
			{"kettle init --at ~/code/x", "initialize somewhere else"},
			{"kettle init --dry-run", "say what it would do, touch nothing"},
		},
		Setup: func(fs *flag.FlagSet) func([]string) error {
			at := fs.String("at", "", "directory to initialize (default: the working directory)")
			login := fs.String("login", "", "name of a login in the machine-wide file (see `kettle auth`)")
			repo := fs.String("repo", "", "tracker repository, as owner/name")
			dryRun := fs.Bool("dry-run", false, "report what would happen; change nothing")

			return func(args []string) error {
				root := *at
				if root == "" {
					wd, err := os.Getwd()
					if err != nil {
						return err
					}
					root = wd
				}
				root, err := filepath.Abs(root)
				if err != nil {
					return err
				}
				if fi, err := os.Stat(root); err != nil || !fi.IsDir() {
					return Fail("%s is not a directory", root)
				}

				// A second marker inside an existing project gives it a second
				// store, and the nearer one wins — which is a surprise worth
				// naming before it happens, not after.
				if existing := project.Root(root); existing != "" && existing != root {
					fmt.Fprintf(os.Stderr,
						"warning: %s already sits inside the project at %s — a second marker here gives it a second store, and the nearer one wins.\n",
						root, existing)
				}

				if *repo != "" {
					if owner, name, ok := strings.Cut(*repo, "/"); !ok || owner == "" || name == "" {
						return Fail("--repo %q is not owner/name", *repo)
					}
				}

				done, err := project.Init(root, *dryRun)
				if err != nil {
					return err
				}

				line, err := writeConfig(root, *login, *repo, *dryRun)
				if err != nil {
					return err
				}
				if line != "" {
					done = append(done, line)
				}

				prefix := ""
				if *dryRun {
					prefix = "would: "
				}
				for _, l := range done {
					fmt.Println(prefix + l)
				}
				return nil
			}
		},
	})
}