package db

import (
	"fmt"
	"time"

	"github.com/bluesky-social/indigo/atproto/syntax"
	"tangled.org/core/appview/models"
)

func UpsertReaction(e Execer, reaction models.Reaction) error {
	_, err := e.Exec(
		`insert into reactions (did, rkey, subject_at, kind, created)
		values (?, ?, ?, ?, ?)
		on conflict(did, rkey) do update set
			subject_at = excluded.subject_at,
			kind       = excluded.kind,
			created    = excluded.created`,
		reaction.ReactedByDid,
		reaction.Rkey,
		reaction.ThreadAt,
		reaction.Kind,
		reaction.Created.Format(time.RFC3339),
	)
	return err
}

// Remove a reaction
func DeleteReaction(e Execer, did syntax.DID, subjectAt syntax.ATURI, kind models.ReactionKind) ([]syntax.ATURI, error) {
	var deleted []syntax.ATURI
	rows, err := e.Query(
		`delete from reactions
		where did = ? and subject_at = ? and kind = ?
		returning at_uri`,
		did,
		subjectAt,
		kind,
	)
	if err != nil {
		return nil, fmt.Errorf("deleting stars: %w", err)
	}
	defer rows.Close()

	for rows.Next() {
		var aturi syntax.ATURI
		if err := rows.Scan(&aturi); err != nil {
			return nil, fmt.Errorf("scanning at_uri: %w", err)
		}
		deleted = append(deleted, aturi)
	}
	return deleted, nil
}

// Remove a reaction
func DeleteReactionByRkey(e Execer, did string, rkey string) error {
	_, err := e.Exec(`delete from reactions where did = ? and rkey = ?`, did, rkey)
	return err
}

func GetReactionCount(e Execer, subjectAt syntax.ATURI, kind models.ReactionKind) (int, error) {
	count := 0
	err := e.QueryRow(
		`select count(did) from reactions where subject_at = ? and kind = ?`, subjectAt, kind).Scan(&count)
	if err != nil {
		return 0, err
	}
	return count, nil
}

func GetReactionMap(e Execer, userLimit int, subjectAt syntax.ATURI) (map[models.ReactionKind]models.ReactionDisplayData, error) {
	query := `
	select kind, did,
	       row_number() over (partition by kind order by created asc) as rn,
	       count(*) over (partition by kind) as total
	from reactions
	where subject_at = ?
	order by kind, created asc`

	rows, err := e.Query(query, subjectAt)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	reactionMap := map[models.ReactionKind]models.ReactionDisplayData{}
	for _, kind := range models.OrderedReactionKinds {
		reactionMap[kind] = models.ReactionDisplayData{Count: 0, Users: []string{}}
	}

	for rows.Next() {
		var kind models.ReactionKind
		var did string
		var rn, total int
		if err := rows.Scan(&kind, &did, &rn, &total); err != nil {
			return nil, err
		}

		data := reactionMap[kind]
		data.Count = total
		if userLimit > 0 && rn <= userLimit {
			data.Users = append(data.Users, did)
		}
		reactionMap[kind] = data
	}

	return reactionMap, rows.Err()
}

func GetReactionStatus(e Execer, userDid string, threadAt syntax.ATURI, kind models.ReactionKind) (bool, error) {
	var exists bool
	err := e.QueryRow(
		`select exists (
			select 1 from reactions
			where did = ? and subject_at = ? and kind = ?
		)`,
		userDid,
		threadAt,
		kind,
	).Scan(&exists)
	return exists, err
}

func GetReactionStatusMap(e Execer, userDid string, threadAt syntax.ATURI) (map[models.ReactionKind]bool, error) {
	statusMap := map[models.ReactionKind]bool{}
	for _, kind := range models.OrderedReactionKinds {
		reacted, err := GetReactionStatus(e, userDid, threadAt, kind)
		if err != nil {
			return nil, err
		}
		statusMap[kind] = reacted
	}
	return statusMap, nil
}