package cmd

import (
	"fmt"
	"strings"
	"time"

	"github.com/lerko/nib/internal/db"
	"github.com/lerko/nib/internal/display"
	"github.com/spf13/cobra"
)

var (
	lsTag   string
	lsDate  string
	lsMonth string
	lsFrom  string
	lsTo    string
	lsLimit int
	lsAll   bool
)

var lsCmd = &cobra.Command{
	Use:   "ls",
	Short: "list entities in stream order",
	RunE:  runLs,
}

func init() {
	lsCmd.Flags().StringVar(&lsTag, "tag", "", "filter by tag")
	lsCmd.Flags().StringVar(&lsDate, "date", "", "filter by date (YYYY-MM-DD)")
	lsCmd.Flags().StringVar(&lsMonth, "month", "", "filter by month (YYYY-MM)")
	lsCmd.Flags().StringVar(&lsFrom, "from", "", "start date (YYYY-MM-DD)")
	lsCmd.Flags().StringVar(&lsTo, "to", "", "end date (YYYY-MM-DD)")
	lsCmd.Flags().IntVar(&lsLimit, "limit", 0, "max entities to show (default 50)")
	lsCmd.Flags().BoolVar(&lsAll, "all", false, "include deleted entities")
}

func runLs(_ *cobra.Command, _ []string) error {
	store, err := openStore()
	if err != nil {
		return err
	}
	defer store.Close()

	p := db.DefaultListParams()
	p.IncludeDeleted = lsAll

	if lsTag != "" {
		p.Tag = &lsTag
	}
	if lsLimit > 0 {
		p.Limit = lsLimit
	}

	hasDateFilter := false
	if lsDate != "" {
		p.Date = &lsDate
		hasDateFilter = true
	}
	if lsMonth != "" {
		t, err := time.Parse("2006-01", lsMonth)
		if err != nil {
			return fmt.Errorf("bad --month format, use YYYY-MM")
		}
		from := t.Format("2006-01-02")
		to := t.AddDate(0, 1, -1).Format("2006-01-02")
		p.From = &from
		p.To = &to
		hasDateFilter = true
	}
	if lsFrom != "" {
		if _, err := time.Parse("2006-01-02", lsFrom); err != nil {
			return fmt.Errorf("bad --from format, use YYYY-MM-DD")
		}
		p.From = &lsFrom
		hasDateFilter = true
	}
	if lsTo != "" {
		if _, err := time.Parse("2006-01-02", lsTo); err != nil {
			return fmt.Errorf("bad --to format, use YYYY-MM-DD")
		}
		p.To = &lsTo
		hasDateFilter = true
	}
	if !hasDateFilter {
		since := time.Now().UTC().Add(-48 * time.Hour)
		p.Since = &since
	}

	entities, err := store.List(p)
	if err != nil {
		return err
	}

	if len(entities) == 0 {
		return nil
	}

	groups := groupByDate(entities)
	for _, g := range groups {
		fmt.Printf("── %s ──\n", g.label)
		for _, e := range g.entities {
			printEntity(e)
		}
		fmt.Println()
	}

	return nil
}

type dateGroup struct {
	label    string
	entities []*db.Entity
}

func groupByDate(entities []*db.Entity) []dateGroup {
	var groups []dateGroup
	var current *dateGroup

	for _, e := range entities {
		label := formatDateLabel(e.CreatedAt)
		if current == nil || current.label != label {
			if current != nil {
				groups = append(groups, *current)
			}
			current = &dateGroup{label: label}
		}
		current.entities = append(current.entities, e)
	}
	if current != nil {
		groups = append(groups, *current)
	}
	return groups
}

func formatDateLabel(t time.Time) string {
	return strings.ToLower(t.Format("Jan 2"))
}

func printEntity(e *db.Entity) {
	glyph := display.DisplayGlyph(e.Glyph, e.CardType)
	shortID := display.FormatID(e.ID)

	label := e.Body
	if e.Title != nil {
		label = *e.Title
	}

	var line strings.Builder
	fmt.Fprintf(&line, "%s  %-40s", glyph, label)

	if e.TimeAnchor != nil {
		fmt.Fprintf(&line, " @%-5s", *e.TimeAnchor)
	} else {
		line.WriteString("        ")
	}

	var tagStr string
	for _, tag := range e.Tags {
		tagStr += " #" + tag
	}
	if tagStr != "" {
		fmt.Fprintf(&line, " %-16s", strings.TrimSpace(tagStr))
	} else {
		line.WriteString("                 ")
	}

	fmt.Fprintf(&line, " %s", shortID)

	if e.UseCount > 0 {
		fmt.Fprintf(&line, "  (%d×)", e.UseCount)
	}

	fmt.Println(line.String())
}