package app

import (
	"context"
	"flag"
	"fmt"
	"io"
	"sort"

	"gitea.maximumdirect.net/eric/narratio/internal/manifest"
)

// Status reads and prints stage statuses from an existing manifest.
func Status(ctx context.Context, args []string, out io.Writer) error {
	fs := flag.NewFlagSet("status", flag.ContinueOnError)
	fs.SetOutput(io.Discard)

	var manifestPath string
	fs.StringVar(&manifestPath, "manifest", "", "path to manifest.json")

	if err := fs.Parse(args); err != nil {
		return fmt.Errorf("status: invalid flags: %w", err)
	}
	if fs.NArg() != 0 {
		return fmt.Errorf("status: unexpected positional arguments")
	}
	if manifestPath == "" {
		return fmt.Errorf("status: --manifest is required")
	}

	store := &manifest.LocalStore{}
	m, err := store.Load(ctx, manifestPath)
	if err != nil {
		return fmt.Errorf("status: %w", err)
	}

	if _, err := fmt.Fprintf(out, "session_id: %s\n", m.SessionID); err != nil {
		return err
	}
	if _, err := fmt.Fprintf(out, "updated_at: %s\n", m.UpdatedAt.UTC().Format("2006-01-02T15:04:05Z07:00")); err != nil {
		return err
	}

	if len(m.Stages) == 0 {
		_, err := fmt.Fprintln(out, "stages: no stages recorded")
		return err
	}

	if _, err := fmt.Fprintln(out, "stages:"); err != nil {
		return err
	}

	names := make([]string, 0, len(m.Stages))
	for name := range m.Stages {
		names = append(names, name)
	}
	sort.Strings(names)

	for _, name := range names {
		status := m.Stages[name].Status
		if _, err := fmt.Fprintf(out, "- %s: %s\n", name, status); err != nil {
			return err
		}
	}

	return nil
}