// Copyright 2026 Beacon Contributors
// SPDX-License-Identifier: AGPL-3.0-or-later

package db

import (
	"context"
	"encoding/hex"
	"errors"
	"time"

	sqlc "github.com/MeshCore-Beacon/beacon-server/db/sqlc"
	"github.com/MeshCore-Beacon/beacon-server/internal/api"
	"github.com/MeshCore-Beacon/beacon-server/internal/ingest"
	"github.com/jackc/pgx/v5"
	"github.com/jackc/pgx/v5/pgtype"
)

func (s *Store) UpsertChannel(ctx context.Context, channelHash []byte, keyFingerprint []byte, name string, hashtag string) (int, error) {
	var namePtr, hashtagPtr *string
	if name != "" {
		namePtr = &name
	}
	if hashtag != "" {
		hashtagPtr = &hashtag
	}
	isHashtag := hashtag != ""
	row, err := s.q.UpsertChannel(ctx, sqlc.UpsertChannelParams{
		ChannelHash: channelHash,
		Column2:     keyFingerprint, // key_fingerprint
		Name:        namePtr,
		Hashtag:     hashtagPtr,
		IsHashtag:   &isHashtag,
	})
	if err != nil {
		return 0, err
	}
	return int(row.ID), nil
}

func (s *Store) UpsertChannelHashOnly(ctx context.Context, channelHash []byte) (int, error) {
	rowID, err := s.q.UpsertChannelHashOnly(ctx, channelHash)
	if err != nil {
		return 0, err
	}
	return int(rowID), nil
}

// ListUndecryptedGroupTextPackets returns GRP_TXT packets never successfully decrypted --
// see internal/ingest.BackfillChannelMessages, which retries these against the current
// keystore at boot.
func (s *Store) ListUndecryptedGroupTextPackets(ctx context.Context) ([]ingest.UndecryptedPacket, error) {
	rows, err := s.q.ListUndecryptedGroupTextPackets(ctx)
	if err != nil {
		return nil, err
	}
	packets := make([]ingest.UndecryptedPacket, 0, len(rows))
	for _, v := range rows {
		packets = append(packets, ingest.UndecryptedPacket{
			PacketHash: v.PacketHash,
			RawPayload: v.RawPayload,
		})
	}
	return packets, nil
}

// ListUndecryptedGroupTextPacketsByHash limits the boot backfill to channels that just gained a key.
func (s *Store) ListUndecryptedGroupTextPacketsByHash(ctx context.Context, hashes [][]byte) ([]ingest.UndecryptedPacket, error) {
	rows, err := s.q.ListUndecryptedGroupTextPacketsByHash(ctx, hashes)
	if err != nil {
		return nil, err
	}
	packets := make([]ingest.UndecryptedPacket, 0, len(rows))
	for _, v := range rows {
		packets = append(packets, ingest.UndecryptedPacket{PacketHash: v.PacketHash, RawPayload: v.RawPayload})
	}
	return packets, nil
}

// SetChannelConfigScopes replaces every configured channel's region placement;
// an empty region means Beacon-wide.
func (s *Store) SetChannelConfigScopes(ctx context.Context, fingerprints [][]byte, regions []string) error {
	if err := s.q.DeleteChannelConfigScopes(ctx); err != nil {
		return err
	}
	if len(fingerprints) == 0 {
		return nil
	}
	return s.q.AddChannelConfigScopes(ctx, sqlc.AddChannelConfigScopesParams{Fingerprints: fingerprints, Regions: regions})
}

func (s *Store) UpsertChannelIATA(ctx context.Context, channelHash []byte, iata string, heardAt time.Time) error {
	return s.q.UpsertChannelIATA(ctx, sqlc.UpsertChannelIATAParams{
		ChannelHash: channelHash,
		Iata:        iata,
		LastHeard:   pgtype.Timestamptz{Time: heardAt, Valid: true},
	})
}

func (s *Store) DeleteOldChannelIATAs(ctx context.Context, cutoff time.Time) error {
	return s.q.DeleteOldChannelIATAs(ctx, pgtype.Timestamptz{Time: cutoff, Valid: true})
}

func (s *Store) ListChannels(ctx context.Context, limit int32, hash []byte, iatas []string, keyKnown *bool, cursor int64, pageCursor *api.ChannelCursor) (api.ChannelPage, error) {
	var cursorTS pgtype.Timestamptz
	if cursor > 0 {
		cursorTS = pgtype.Timestamptz{Time: time.UnixMilli(cursor), Valid: true}
	}
	var rows []sqlc.Channel
	var err error
	if pageCursor != nil {
		rows, err = s.q.ListChannelsAfter(ctx, sqlc.ListChannelsAfterParams{
			ChannelHash: hash, Iatas: iatas, KeyKnown: keyKnown, PageLimit: limit + 1,
			CursorTs: pgtype.Timestamptz{Time: pageCursor.LastSeen, Valid: true}, CursorID: pageCursor.ID,
		})
	} else {
		rows, err = s.q.ListChannels(ctx, sqlc.ListChannelsParams{
			ChannelHash: hash, Iatas: iatas, KeyKnown: keyKnown, CursorTs: cursorTS, PageLimit: limit + 1,
		})
	}
	if err != nil {
		return api.ChannelPage{}, err
	}
	hasMore := len(rows) > int(limit)
	if hasMore {
		rows = rows[:limit]
	}
	items := make([]api.ChannelSummary, 0, len(rows))
	for _, v := range rows {
		items = append(items, api.ChannelSummary{
			ID:          int(v.ID),
			Name:        v.Name,
			ChannelHash: hex.EncodeToString(v.ChannelHash),
			LastSeen:    v.LastSeen.Time.UnixMilli(),
			IsHashtag:   v.IsHashtag != nil && *v.IsHashtag,
			KeyKnown:    v.KeyKnown != nil && *v.KeyKnown,
		})
	}
	var nextCursor *int64
	var nextPageCursor *string
	if hasMore {
		last := items[len(items)-1].LastSeen
		nextCursor = &last
		row := rows[len(rows)-1]
		precise := (api.ChannelCursor{LastSeen: row.LastSeen.Time, ID: row.ID}).String()
		nextPageCursor = &precise
	}
	return api.ChannelPage{
		Page:           api.Page[api.ChannelSummary]{Items: items, NextCursor: nextCursor, HasMore: hasMore},
		NextPageCursor: nextPageCursor,
	}, nil
}

func (s *Store) GetChannel(ctx context.Context, channelID int32) (*api.Channel, error) {
	row, err := s.q.GetChannelByID(ctx, channelID)
	if err != nil {
		return nil, err
	}
	channel := api.Channel{
		ChannelSummary: api.ChannelSummary{
			ID:          int(row.ID),
			Name:        row.Name,
			ChannelHash: hex.EncodeToString(row.ChannelHash),
			LastSeen:    row.LastSeen.Time.UnixMilli(),
			IsHashtag:   row.IsHashtag != nil && *row.IsHashtag,
			KeyKnown:    row.KeyKnown != nil && *row.KeyKnown,
		},
		Hashtag:      row.Hashtag,
		MessageCount: row.MessageCount,
	}
	if row.IsHashtag != nil && *row.IsHashtag && row.KeyFingerprint != nil {
		fp := hex.EncodeToString(row.KeyFingerprint)
		channel.KeyFingerprint = &fp
	}
	return &channel, nil
}

func (s *Store) InsertChannelMessage(ctx context.Context, m ingest.InsertChannelMessageParams) (*ingest.InsertedChannelMessage, error) {
	params := sqlc.InsertChannelMessageParams{ChannelID: int32(m.ChannelID), PacketHash: m.PacketHash, SenderName: &m.SenderName, Content: &m.Content, SentAt: pgtype.Timestamptz{Time: m.SentAt, Valid: true}, Column6: m.Historical}
	row, err := s.q.InsertChannelMessage(ctx, params)
	if errors.Is(err, pgx.ErrNoRows) {
		return nil, nil // duplicate
	}
	if err != nil {
		return nil, err
	}
	return &ingest.InsertedChannelMessage{ID: row.ID, Scope: row.ScopeName, ScopeStatus: api.RecordedChannelScopeStatus(row.ScopeName, row.TransportCodesPresent)}, nil
}

func (s *Store) ListChannelMessages(ctx context.Context, channelID *int32, since time.Time, limit int32, iatas []string, scope string, cursor int64) (api.Page[api.ChannelMessage], error) {
	ts := pgtype.Timestamptz{Time: since, Valid: !since.IsZero()}
	var messages []api.ChannelMessage
	var hasMore bool
	if channelID == nil {
		rows, err := s.q.ListAllChannelMessages(ctx, sqlc.ListAllChannelMessagesParams{
			Column1: ts,
			Column2: iatas,
			Column3: scope,
			Column4: cursor,
			Limit:   limit + 1,
		})
		if err != nil {
			return api.Page[api.ChannelMessage]{}, err
		}
		hasMore = len(rows) > int(limit)
		if hasMore {
			rows = rows[:limit]
		}
		messages = make([]api.ChannelMessage, 0, len(rows))
		for _, v := range rows {
			messages = append(messages, toChannelMessage(v.ID, v.PacketHashHex, v.ChannelHash, v.SenderName, v.Content, v.SentAt, v.ObservationCount, v.ScopeName, v.TransportCodesPresent))
		}
	} else {
		rows, err := s.q.ListChannelMessages(ctx, sqlc.ListChannelMessagesParams{
			ChannelID: *channelID,
			Column2:   ts,
			Column3:   iatas,
			Column4:   scope,
			Column5:   cursor,
			Limit:     limit + 1,
		})
		if err != nil {
			return api.Page[api.ChannelMessage]{}, err
		}
		hasMore = len(rows) > int(limit)
		if hasMore {
			rows = rows[:limit]
		}
		messages = make([]api.ChannelMessage, 0, len(rows))
		for _, v := range rows {
			messages = append(messages, toChannelMessage(v.ID, v.PacketHashHex, v.ChannelHash, v.SenderName, v.Content, v.SentAt, v.ObservationCount, v.ScopeName, v.TransportCodesPresent))
		}
	}

	var nextCursor *int64
	if hasMore && len(messages) > 0 {
		last := messages[len(messages)-1].ID
		nextCursor = &last
	}
	return api.Page[api.ChannelMessage]{
		Items:      messages,
		NextCursor: nextCursor,
		HasMore:    hasMore,
	}, nil
}

func (s *Store) ListChannelMessagesByHash(ctx context.Context, hash []byte, since time.Time, limit int32, iatas []string, scope string, cursor int64) (api.Page[api.ChannelMessage], error) {
	rows, err := s.q.ListChannelMessagesByHash(ctx, sqlc.ListChannelMessagesByHashParams{
		ChannelHash: hash,
		Column2:     pgtype.Timestamptz{Time: since, Valid: !since.IsZero()},
		Column3:     iatas,
		Column4:     scope,
		Column5:     cursor,
		Limit:       limit + 1,
	})
	if err != nil {
		return api.Page[api.ChannelMessage]{}, err
	}
	hasMore := len(rows) > int(limit)
	if hasMore {
		rows = rows[:limit]
	}
	messages := make([]api.ChannelMessage, 0, len(rows))
	for _, v := range rows {
		messages = append(messages, toChannelMessage(v.ID, hex.EncodeToString(v.PacketHash), v.ChannelHash, v.SenderName, v.Content, v.SentAt, v.ObservationCount, v.ScopeName, v.TransportCodesPresent))
	}
	var nextCursor *int64
	if hasMore && len(messages) > 0 {
		last := messages[len(messages)-1].ID
		nextCursor = &last
	}
	return api.Page[api.ChannelMessage]{
		Items:      messages,
		NextCursor: nextCursor,
		HasMore:    hasMore,
	}, nil
}

func (s *Store) ListMessagesAfterID(ctx context.Context, afterID int64, iatas []string, scope string, limit int32) ([]api.ChannelMessage, error) {
	rows, err := s.q.ListMessagesAfterID(ctx, sqlc.ListMessagesAfterIDParams{
		ID:      afterID,
		Column2: iatas,
		Column3: scope,
		Limit:   limit,
	})
	if err != nil {
		return nil, err
	}
	items := make([]api.ChannelMessage, 0, len(rows))
	for _, v := range rows {
		items = append(items, toChannelMessage(
			v.ID,
			v.PacketHashHex,
			v.ChannelHash,
			v.SenderName,
			v.Content,
			v.SentAt,
			v.ObservationCount,
			v.ScopeName,
			v.TransportCodesPresent,
		))
	}
	return items, nil
}