const mysql = require("mysql2/promise")
const dayjs = require("dayjs")

const log = require("../logger")
const searchLib = require("./search")
const {host, port, user, database, password} = require("./../settings").db

/////////////////////////////////////////////////////////////////////////

let poolP = initPool()

async function initPool() {
    return mysql.createPool({
        host,
        port,
        database,
        user,
        password,
    })
}

/////////////////////////////////////////////////////////////////////////

module.exports = {
    getUsers,
    getUserCount,
    getUserByLogin,
    getUserByUserId,
    getUserDefinedFields,
    getUserDefinedField,
    getUserTeilnahmen,

    getObjIdFromRefId,
    getRefIdFromObjId,

    getKurse,
    getKurs,
    getKursItems,
    getKursItems2,
    // getKursByObjId,
    // getKursByRefId,
    getKursTeilnehmer,
    getSingleKursTeilnehmer,
    getKursTeilnehmerCount,

    getKursLp,
    getKursUnterobjektLp,

    getKursOffline,
    setKursOffline,

    getUdf,

    getKursTeilnehmerRolle,
    getKursTeilnehmerByRole,
    getKursRoles,

    setStatus,
}

/////////////////////////////////////////////////////////////////////////

async function getUserSearchQuery(offset, limit, search) {
    const sel = `usr_id, login, firstname, lastname, gender, email, institution, street, city, zipcode, country, department, active`
    if (!search || search === '') {
        return `SELECT ${sel}
                FROM ${database}.usr_data AS ud
                WHERE login REGEXP '^[0-9]+$'
              LIMIT ${limit}
                OFFSET ${offset}
        `
    } else {
        const ids = await searchLib.search(search)
        if (!ids.length) {
            throw "nothing found"
            return await getUserSearchQuery(offset, limit)
        } // nothing found
        return `SELECT ${sel}
                FROM ${database}.usr_data AS ud
                WHERE login REGEXP '^[0-9]+$'
              AND usr_id IN (${ids.join(",")})
                    LIMIT ${limit}
                OFFSET ${offset}
        `
    }
}

async function getUsers(offset = 0, limit = 10, search = null) {
    log.info("++++++++++ get users", offset, limit, search)
    limit = Number(limit) || 10
    offset = Number(offset) || 0
    // TODO check args for SQL Injection

    const pool = await poolP

    try {
        let userSearchQuery = await getUserSearchQuery(offset, limit, search)
        // log.info(userSearchQuery)
        const [results, fields] = await pool.query(userSearchQuery)
        // console.log(results, fields)
        const count = await getUserCount(offset, limit, search)
        return {
            total: count,
            offset, limit,
            data: results,
        }
    } catch (ex) {
        return {
            total: 0,
            offset: 0,
            limit: 0,
            data: [],
        }
    }
}

async function getUserCount(offset, limit, search) {
    const pool = await poolP
    // const q = getUserSearchQuery(offset, limit, search)
    const q = await getUserSearchQuery(0, 1000000, search) // hier darf kein Limit sein, offset=0
    const q2 = `SELECT COUNT(*) AS count
                FROM (${q}) AS X`
    const [results, fields] = await pool.query(q2)
    return results[0].count

    // const [results, fields] = await pool.query(
    //    `SELECT COUNT(*)
    //     FROM ${database}.usr_data AS ud
    //     WHERE login REGEXP '^[0-9]+$'`
    // )
    // return results[0]["COUNT(*)"]
}

async function getUserByLogin(login) {
    const sel = `usr_id, login, firstname, lastname, gender, email, institution, street, city, zipcode, country, department, active`
    // TODO check args for SQL Injection

    const pool = await poolP
    const [results, fields] = await pool.query(
        `SELECT ${sel}
         FROM ${database}.usr_data AS ud
         WHERE login = '${login}'`
    )
    return joinUDF(results[0])
}

async function getUserByUserId(userId) {
    const sel = `usr_id, login, firstname, lastname, gender, email, institution, street, city, zipcode, country, department, active`
    // TODO check args for SQL Injection

    const pool = await poolP
    const [results, fields] = await pool.query(
        `SELECT ${sel}
         FROM ${database}.usr_data AS ud
         WHERE usr_id = '${userId}'`
    )
    return joinUDF(results[0])
}

async function getUserDefinedFields() {
    const pool = await poolP
    const [results] = await pool.query(
        `SELECT ut.usr_id, ud.field_name, ut.value
         FROM ${database}.udf_definition ud
                  JOIN ${database}.udf_text ut ON ut.field_id = ud.field_id`
    )
    return results
}

async function getUserDefinedField(usr_id) {
    const pool = await poolP
    const [results] = await pool.query(
        `SELECT ut.usr_id, ud.field_name, ut.value
         FROM ${database}.udf_definition ud
                  JOIN ${database}.udf_text ut ON ut.field_id = ud.field_id
         WHERE ut.usr_id = '${usr_id}'
        `
    )
    return results
}

/////// obj_id / ref_id ////////////////////////////////////////////////////////////////

/**
 * @param refId
 * @returns {Promise<{ref_id,obj_id}|undefined>}
 */
async function getObjIdFromRefId(refId) {
    const pool = await poolP
    const [results] = await pool.query(
        `SELECT ref_id, obj_id
         FROM ${database}.object_reference as obr
         WHERE obr.ref_id = ${refId}
        `
    )
    return results.length ? results[0] : undefined
}

async function getRefIdFromObjId(objId) {
    const pool = await poolP
    const [results] = await pool.query(
        `SELECT ref_id, obj_id
         FROM ${database}.object_reference as obr
         WHERE obr.obj_id = ${objId}
        `
    )
    return results.length ? results[0] : undefined
}

/////////////////////////////////////////////////////////////////////////

async function promiseDelay(ms) {
    return new Promise(resolve => setTimeout(resolve, ms))
}

async function joinUDF(user) {
    if (!user) return user
    const fields = await getUserDefinedField(user.usr_id)
    for (const field of fields) {
        user[field.field_name] = field.value
    }
    return user
}

/////// Kurs ////////////////////////////////////////////////////////////////

async function getKurse() {
    const pool = await poolP
    const q = `SELECT or2.ref_id, or2.obj_id, od.title, od.description, od.type, od.offline
               FROM ${database}.object_reference or2
                        INNER JOIN ${database}.object_data od ON od.obj_id = or2.obj_id
               WHERE od.type = 'crs'
                 AND or2.deleted IS NULL
    `
    const [results] = await pool.query(q)
    return results
}

// async function getKursByRefId (refId) {
//    const {ref_id, obj_id} = await getObjIdFromRefId(refId)
//    return getKursByObjId(obj_id)
// }

async function getKurs(ref_id) {
    const pool = await poolP
    const q = `SELECT or2.ref_id, or2.obj_id, od.title, od.description, od.type, od.create_date, od.offline
               FROM ${database}.object_reference or2
                        INNER JOIN ${database}.object_data od ON od.obj_id = or2.obj_id
               WHERE or2.ref_id = '${ref_id}'
                 AND or2.deleted IS NULL
    `
    let [results] = await pool.query(q)
    results = results.length ? results[0] : undefined
    return results
}

async function getKursItems(ref_id) {
    const pool = await poolP
    // const q = `SELECT or2.ref_id, or2.obj_id, od.title, od.description, od.type
    //            FROM ${database}.object_reference or2
    //            INNER JOIN ${database}.object_data od ON od.obj_id = or2.obj_id
    //            WHERE or2.obj_id = '${obj_id}'
    // `
    const q = `SELECT ci.parent_id, or2.ref_id, or2.obj_id, od.title, od.type
               FROM ${database}.crs_items ci
                        INNER JOIN ${database}.object_reference or2 ON or2.ref_id = ci.obj_id
                        INNER JOIN ${database}.object_data od ON od.obj_id = or2.obj_id
               WHERE or2.ref_id = ${ref_id}
                  OR parent_id = ${ref_id}
                   AND or2.deleted is NULL
    `
    const [results] = await pool.query(q)
    return results
}

async function getKursItems2(ref_id) {
    const pool = await poolP
    const q = `
        WITH RECURSIVE tree (parent_id, obj_id, ref_id, title, type) AS
                           (SELECT ci.parent_id,
                                   or2.obj_id,
                                   ci.obj_id as ref_id,
                                   od.title,
                                   od.type
                            FROM ${database}.crs_items ci
                                     INNER JOIN ${database}.object_reference or2 ON or2.ref_id = ci.obj_id
                                     INNER JOIN ${database}.object_data od ON od.obj_id = or2.obj_id
                            WHERE ci.obj_id = ${ref_id} -- Kurs ref_id
                              AND or2.deleted is NULL

                            UNION ALL

                            SELECT child.parent_id,
                                   or2.obj_id,
                                   child.obj_id as ref_id,
                                   od.title,
                                   od.type
                            FROM ${database}.crs_items child
                                     INNER JOIN ${database}.object_reference or2 ON or2.ref_id = child.obj_id
                                     INNER JOIN ${database}.object_data od ON od.obj_id = or2.obj_id
                                     JOIN tree ON child.parent_id = tree.ref_id
                            WHERE or2.deleted is NULL)
        SELECT *
        FROM tree
        ORDER BY tree.ref_id
    `
    const [results] = await pool.query(q)
    return results
}

async function getKursTeilnehmer(ref_id) {
    const pool = await poolP
    const q = `SELECT ci.parent_id,
                      or2.ref_id,
                      or2.obj_id,
                      od.title,
                      od.type,
                      om.usr_id,
                      ud.login,
                      ud.firstname,
                      ud.lastname,
                      ud.active,
                      om.passed,
                      ulm.status,
                      ulm.status_changed
               FROM ${database}.crs_items ci
                        INNER JOIN ${database}.object_reference or2 ON or2.ref_id = ci.obj_id
                        INNER JOIN ${database}.object_data od ON od.obj_id = or2.obj_id
                        INNER JOIN ${database}.obj_members om ON om.obj_id = or2.obj_id AND om.member = 1
                        INNER JOIN ${database}.usr_data ud ON ud.usr_id = om.usr_id
                        LEFT JOIN ${database}.ut_lp_marks ulm ON ulm.obj_id = or2.obj_id AND ud.usr_id = ulm.usr_id
               WHERE (or2.ref_id = ${ref_id} OR parent_id = ${ref_id})
                 AND or2.deleted IS NULL
               ORDER BY usr_id
    `
    // log.info(q)
    const [results] = await pool.query(q)
    return results
}

async function getSingleKursTeilnehmer(ref_id, usr_id) {
    const pool = await poolP
    const q = `SELECT ci.parent_id,
                      or2.ref_id,
                      or2.obj_id,
                      od.title,
                      od.type,
                      om.usr_id,
                      ud.login,
                      ud.firstname,
                      ud.lastname,
                      ud.active,
                      om.passed,
                      ulm.status,
                      ulm.status_changed
               FROM ${database}.crs_items ci
                        INNER JOIN ${database}.object_reference or2 ON or2.ref_id = ci.obj_id
                        INNER JOIN ${database}.object_data od ON od.obj_id = or2.obj_id
                        INNER JOIN ${database}.obj_members om ON om.obj_id = or2.obj_id AND om.member = 1
                        INNER JOIN ${database}.usr_data ud ON ud.usr_id = om.usr_id
                        LEFT JOIN ${database}.ut_lp_marks ulm ON ulm.obj_id = or2.obj_id AND ud.usr_id = ulm.usr_id
               WHERE (or2.ref_id = ${ref_id}
                   OR parent_id = ${ref_id})
                 AND om.usr_id = ${usr_id}
               ORDER BY usr_id
    `
    // log.info(q)
    const [results] = await pool.query(q)
    return results[0]
}

async function getKursTeilnehmerCount(ref_id) {
    const pool = await poolP
    const q = `SELECT COUNT(*) as count
               FROM ${database}.crs_items ci
                   INNER JOIN ${database}.object_reference or2
               ON or2.ref_id = ci.obj_id
                   INNER JOIN ${database}.object_data od ON od.obj_id = or2.obj_id
                   INNER JOIN ${database}.obj_members om ON om.obj_id = or2.obj_id AND om.member = 1
                   INNER JOIN ${database}.usr_data ud ON ud.usr_id = om.usr_id
                   LEFT JOIN ${database}.ut_lp_marks ulm ON ulm.obj_id = or2.obj_id AND ud.usr_id = ulm.usr_id
               WHERE (or2.ref_id = ${ref_id}
                  OR parent_id = ${ref_id})
               ORDER BY usr_id
    `
    let [results] = await pool.query(q)
    results = results.length ? results[0] : undefined
    return {ref_id, count: results.count}
}

async function getUserTeilnahmen(usr_id) {
    const pool = await poolP
    const q = `SELECT om.obj_id, or2.ref_id, om.usr_id, od.title, ulm.status, om.passed, ulm.status_changed
               FROM ${database}.obj_members om
                        INNER JOIN ${database}.object_reference or2 ON or2.obj_id = om.obj_id
                        INNER JOIN ${database}.usr_data ud ON ud.usr_id = om.usr_id
                        INNER JOIN ${database}.object_data od ON od.obj_id = om.obj_id
                        LEFT JOIN ${database}.ut_lp_marks ulm
                                  ON ulm.usr_id = om.usr_id AND ulm.obj_id = om.obj_id
               WHERE om.usr_id = ${usr_id}
                 AND om.member = 1
    `
    // log.info(q).catch(console.error)
    const [results] = await pool.query(q)
    return results
}

async function getKursLp(obj_id) {

}

async function getKursUnterobjektLp(obj_id) {
    const pool = await poolP
    const q = `SELECT ulc.obj_id,
                      ulc.item_id,
                      ulc.lpmode,
                      t.obj_id as item_obj_id,
                      ulm.usr_id,
                      ulm.status,
                      ulm.status_changed,
                      ulm.percentage,
                      ulm.completed
               FROM ${database}.ut_lp_collections ulc
                        INNER JOIN ${database}.object_reference t ON t.ref_id = ulc.item_id
                        INNER JOIN ${database}.ut_lp_marks ulm ON ulm.obj_id = t.obj_id
               WHERE ulc.obj_id = ${obj_id} # obj_id Kurs
                    AND ulc.active = 1
                    AND ulc.lpmode = 5  # nur mode 5
    `
    const [results] = await pool.query(q)
    return results
}


async function getKursOffline(obj_id) {
    const pool = await poolP
    const q = `SELECT offline
               FROM ${database}.object_data
               WHERE obj_id = ${obj_id}
    `
    const [results] = await pool.query(q)
    return results[0]
}

async function setKursOffline(isOffline, obj_id) {
    const pool = await poolP
    const q = `UPDATE ${database}.object_data
               SET offline = ${isOffline}
               WHERE obj_id = ${obj_id}
    `
    const [results] = await pool.query(q)
    // return results
    return {offline: isOffline}
}

/////// UDF ////////////////////////////////////////////////////////////////

async function getUdf() {
    const pool = await poolP
    const q = `SELECT field_id, field_name, field_type
               from ${database}.udf_definition;`
    const [results] = await pool.query(q)
    return results
}

/////// ROLLEN ////////////////////////////////////////////////////////////////

async function getKursTeilnehmerRolle(obj_id) {
    const pool = await poolP
    const q = `SELECT obj_id, title, description
               from object_data od
               WHERE type = "role" #AND title LIKE 'il_crs_member_157'
                AND od.description LIKE 'Member%${obj_id}'
    `
    const [results] = await pool.query(q)
    // darf nur einen Treffer ergeben
    if (results.length) {
        const {obj_id, title, description} = results[0]
        return obj_id
    } else {
        return null
    }
}

async function getKursTeilnehmerByRole(obj_id) {
    const pool = await poolP
    const q = `
        SELECT obj_id as role_id, ru.usr_id, ud.firstname, ud.lastname
        FROM ${database}.object_data od
                 INNER JOIN ${database}.rbac_ua ru ON ru.rol_id = od.obj_id
                 INNER JOIN ${database}.usr_data ud ON ud.usr_id = ru.usr_id
        WHERE type = "role" #AND title LIKE 'il_crs_member_157'
                AND od.description LIKE 'Member%${obj_id}'
    `
    const [results] = await pool.query(q)
    return results
}

async function getKursRoles(ref_id) {
    const pool = await poolP
    const q = `
        SELECT pa.rol_id, or2.ref_id, or2.obj_id, od2.type, od2.title, od2.description
        FROM ${database}.rbac_pa pa
                 INNER JOIN ${database}.object_reference or2 ON or2.ref_id = pa.ref_id
                 INNER JOIN ${database}.object_data od ON od.obj_id = or2.obj_id
                 INNER JOIN ${database}.object_data od2 ON od2.obj_id = pa.rol_id
        WHERE pa.ref_id = ${ref_id}
    `
    const [results] = await pool.query(q)
    return results
}


/////// STATUS ////////////////////////////////////////////////////////////////

/**
 * Zwei Möglichkeiten:
 * 1. es gibt schon einen Eintrag in ut_lp_marks, dann muss man diesen updaten
 * 2. es gibt noch keinen Eintrag in ut_lp_marks, dann muss erst einer erstellt werden (NEIN! Für neuen TN sind bereits beide Einträge vorhanden, kann also wegfallen)
 *
 * Weiterhin haben wir es mit zwei Tabellen zu tun:
 *    - obj_members (passed)
 *    - ut_lp_marks (status)
 *
 * UPDATE: Wir nehmen an, dass beide Einträge schon vorhanden sind!
 *
 * @param courseId
 * @param userId
 * @param {Number} passed
 * @param {Number} status
 * @returns {Promise<{status: string}>}
 */
async function setStatus(courseId, userId, passed = null, status = null) {
    const pool = await poolP
    log.info(`------------setStatus----- courseId=${courseId}  userId=${userId}  passed=${passed}  status=${status}`)
    passed = isNaN(Number(passed)) ? passed : Number(passed)
    status = isNaN(Number(status)) ? status : Number(status)

    // ACHTUNG Transactions funktioneren so nicht, erst mal ohne machen...
    const q = `
START TRANSACTION;

UPDATE ${database}.ut_lp_marks ulm  
SET status = ${status}
WHERE ulm.usr_id = 31793 AND ulm.obj_id = 32212;

UPDATE ${database}.obj_members om 
SET passed = ${passed}
WHERE om.usr_id = ${userId} AND om.obj_id = ${courseId};

COMMIT;
`

    let date = dayjs().format('YYYY-MM-DD HH:mm:ss')
    const q1 = `
        UPDATE ${database}.ut_lp_marks ulm
        SET status         = ${status},
            status_changed = "${date}"
        WHERE ulm.usr_id = ${userId}
          AND ulm.obj_id = ${courseId};
    `
    const q2 = `
        UPDATE ${database}.obj_members om
        SET passed = ${passed}
        WHERE om.usr_id = ${userId}
          AND om.obj_id = ${courseId};
    `

    const [results1] = await pool.query(q1)
    const [results2] = await pool.query(q2)
    const {affectedRows: affectedRows1} = results1
    const {affectedRows: affectedRows2} = results2

    if (affectedRows1 && affectedRows2) {
        return {status: "ok"}
    } else {
        throw {
            status: "error",
            reason: {affectedRows1, affectedRows2}
        }
    }
}