const { pool } = require("../modules/database")
const { DefaultError } = require("../errors/errors")

async function findById(id) {
    try {
        const sql = "SELECT * FROM users WHERE id = ?"
        const rows = await pool.query(sql, [id])
        return rows[0] || null
    } catch (error) {
        throw new DefaultError(500, "Internal Server Error", error)
    }
}

async function findByIdentifier(identifier) {
    try {
        const sql = "SELECT * FROM users WHERE identifier = ?"
        const rows = await pool.query(sql, [identifier])
        return rows[0] || null
    } catch (error) {
        throw new DefaultError(500, "Internal Server Error", error)
    }
}

async function create(identifier, serverId, remoteId = null, displayName, avatarUrl) {
    try {
        const sql = "INSERT INTO users (identifier, serverId, remoteId, displayName, avatarUrl) VALUES (?, ?, ?, ?, ?) RETURNING *"
        const rows = await pool.query(sql, [identifier, serverId, remoteId, displayName, avatarUrl])
        return rows[0] || null
    } catch (error) {
        if (error.code && error.code == "ER_DUP_ENTRY") {
            throw new DefaultError(401, "Identifier already taken.", "Identifier already assigned.")
        }
        throw new DefaultError(500, "Internal Server Error", error)
    }
}

async function remove(id) {
    try {
        const sql = "DELETE FROM users WHERE id = ?"
        const rows = await pool.query(sql, [id])
        return rows.affectedRows > 0
    } catch (error) {
        throw new DefaultError(500, "Internal Server Error", error)
    }
}

async function isLocal(id) {
    const sql = "SELECT (remoteId IS NULL) AS isLocal FROM users WHERE id = ?"
    const rows = await db.query(sql, [id])

    if (rows.length === 0) {
        throw new DefaultError(404, `User ${id} not found`)
    }

    return Boolean(rows[0].isLocal)
}

async function updateProfile(id, displayName, avatarUrl) {
    try {
        const fields = []
        const params = []

        if (displayName !== undefined) {
            fields.push('`displayName` = ?')
            params.push(displayName)
        }

        if (avatarUrl !== undefined) {
            fields.push('`avatarUrl` = ?')
            params.push(avatarUrl)
        }

        if (fields.length === 0) {
            return findById(id)
        }

        params.push(id)

        const sql = `UPDATE users SET ${fields.join(', ')} WHERE id = ?`
        await pool.query(sql, params)

        return findById(id)
    } catch (error) {
        console.error(error)
        throw new DefaultError(500, "Internal Server Error", error)
    }
}

async function findByServerAndRemoteId(serverId, remoteId) {
    try {
        const sql = "SELECT * FROM users WHERE serverId = ? AND remoteId = ?"
        const rows = await pool.query(sql, [serverId, remoteId])
        return rows[0] || null
    } catch (error) {
        throw new DefaultError(500, "Internal Server Error", error)
    }
}

module.exports = {
    create,
    remove,
    isLocal,
    findById,
    updateProfile,
    findByIdentifier,
    findByServerAndRemoteId
}