package database

import (
	"database/sql"
	"errors"
	"fmt"

	log "maunium.net/go/maulogger/v2"

	"maunium.net/go/mautrix/util/dbutil"
)

type GuildQuery struct {
	db  *Database
	log log.Logger
}

const (
	guildSelect = "SELECT discord_id, guild_id, guild_name, bridge FROM guild"
)

func (gq *GuildQuery) New() *Guild {
	return &Guild{
		db:  gq.db,
		log: gq.log,
	}
}

func (gq *GuildQuery) Get(discordID, guildID string) *Guild {
	query := guildSelect + " WHERE discord_id=$1 AND guild_id=$2"

	row := gq.db.QueryRow(query, discordID, guildID)
	if row == nil {
		return nil
	}

	return gq.New().Scan(row)
}

func (gq *GuildQuery) GetAll(discordID string) []*Guild {
	query := guildSelect + " WHERE discord_id=$1"

	rows, err := gq.db.Query(query, discordID)
	if err != nil || rows == nil {
		return nil
	}

	guilds := []*Guild{}
	for rows.Next() {
		guilds = append(guilds, gq.New().Scan(rows))
	}

	return guilds
}

func (gq *GuildQuery) Prune(discordID string, guilds []string) {
	// We need this interface slice because a variadic function can't mix
	// arguements with a `...` expanded slice.
	args := []interface{}{discordID}

	nGuilds := len(guilds)
	if nGuilds <= 0 {
		return
	}

	gq.log.Debugfln("prunning guilds for %s", discordID)

	// Build the in query
	inQuery := "$2"
	for i := 1; i < nGuilds; i++ {
		inQuery += fmt.Sprintf(", $%d", i+2)
	}

	// Add the arguements for the build query
	for _, guildID := range guilds {
		args = append(args, guildID)
	}

	// Now remove any guilds that the user has left.
	query := "DELETE FROM guild WHERE discord_id=$1 AND guild_id NOT IN (" +
		inQuery + ")"

	_, err := gq.db.Exec(query, args...)
	if err != nil {
		gq.log.Warnfln("Failed to remove old guilds for user %s: %v", discordID, err)
	}
}

type Guild struct {
	db  *Database
	log log.Logger

	DiscordID string
	GuildID   string
	GuildName string
	Bridge    bool
}

func (g *Guild) Scan(row dbutil.Scannable) *Guild {
	err := row.Scan(&g.DiscordID, &g.GuildID, &g.GuildName, &g.Bridge)
	if err != nil {
		if !errors.Is(err, sql.ErrNoRows) {
			g.log.Errorln("Database scan failed:", err)
		}

		return nil
	}

	return g
}

func (g *Guild) Upsert() {
	query := "INSERT INTO guild" +
		" (discord_id, guild_id, guild_name, bridge)" +
		" VALUES ($1, $2, $3, $4)" +
		" ON CONFLICT(discord_id, guild_id)" +
		" DO UPDATE SET guild_name=excluded.guild_name, bridge=excluded.bridge"

	_, err := g.db.Exec(query, g.DiscordID, g.GuildID, g.GuildName, g.Bridge)

	if err != nil {
		g.log.Warnfln("Failed to upsert guild %s for %s: %v", g.GuildID, g.DiscordID, err)
	}
}

func (g *Guild) Delete() {
	query := "DELETE FROM guild WHERE discord_id=$1 AND guild_id=$2"

	_, err := g.db.Exec(query, g.DiscordID, g.GuildID)

	if err != nil {
		g.log.Warnfln("Failed to delete guild %s for user %s: %v", g.GuildID, g.DiscordID, err)
	}
}