import AppClass from '../../../../lib/src/lifecycle/AppClass.ts'
import {Connection} from '../../db/Connection.ts'
import {Collection} from '../../../../lib/src/collection/Collection.ts'
import {Table} from './Table.ts'
import {Builder} from '../../builder/Builder.ts'
import {Join} from '../../builder/type/join/Join.ts'

export class Database extends AppClass {
    private _table_cache?: Collection<Table>
    protected _rename?: string

    protected _owner?: string
    protected _owner_override?: string
    public owner(set?: string) {
        if ( set ) {
            this._owner_override = set
            return this
        } else {
            return this._owner_override || this._owner
        }
    }

    protected _encoding?: string
    protected _encoding_override?: string
    public encoding(set?: string) {
        if ( set ) {
            this._encoding_override = set
            return this
        } else {
            return this._encoding_override || this._encoding
        }
    }

    protected _lc_collate?: string
    protected _lc_collate_override?: string
    public lc_collate(set?: string) {
        if ( set ) {
            this._lc_collate_override = set
            return this
        } else {
            return this._lc_collate_override || this._lc_collate
        }
    }

    protected _lc_ctype?: string
    protected _lc_ctype_override?: string
    public lc_ctype(set?: string) {
        if ( set ) {
            this._lc_ctype_override = set
            return this
        } else {
            return this._lc_ctype_override || this._lc_ctype
        }
    }

    protected _tablespace?: string
    protected _tablespace_override?: string
    public tablespace(set?: string) {
        if ( set ) {
            this._tablespace_override = set
            return this
        } else {
            return this._tablespace_override || this._tablespace
        }
    }

    protected _is_template?: boolean
    protected _is_template_override?: boolean
    public is_template(set?: boolean) {
        if ( typeof set !== 'undefined' ) {
            this._is_template_override = set
            return this
        } else {
            return (typeof this._is_template_override !== 'undefined' ? this._is_template_override : this._is_template)
        }
    }

    protected _allow_conn?: boolean
    protected _allow_conn_override?: boolean
    public allow_conn(set?: boolean) {
        if ( typeof set !== 'undefined' ) {
            this._allow_conn_override = set
            return this
        } else {
            return (typeof this._allow_conn_override !== 'undefined' ? this._allow_conn_override : this._allow_conn)
        }
    }

    protected _conn_limit?: number
    protected _conn_limit_override?: number
    public connection_limit(set?: number) {
        if ( typeof set !== 'undefined' ) {
            this._conn_limit_override = set
        } else {
            return (typeof this._conn_limit_override !== 'undefined' ? this._conn_limit_override : this._conn_limit)
        }
    }

    constructor(
        public readonly connection: Connection,
        public readonly name: string,
    ) { super() }

    rename(name: string): this {
        this._rename = name
        return this
    }

    async introspect() {
        this._table_cache = await this.connection.tables(this.name)
        this._table_cache.each((table: Table) => table.set_database(this))

        const query = (new Builder).select(
                'pg_catalog.pg_get_userbyid(db.datdba) AS owner',
                'pg_encoding_to_char(db.encoding) AS encoding_char',
                'datcollate',
                'datctype',
                'tablespace.spcname AS tablespace',
                'datistemplate',
                'datallowconn',
                'datconnlimit'
            )
            .from('pg_catalog.pg_database', 'db')
            .join('pg_catalog.pg_tablespace', 'tablespace', (join: Join) => {
                join.whereRaw('db.dattablespace', '=', 'tablespace.oid')
            })
            .where('db.datname', '=', this.name)
            .target_connection(this.connection)

        const info: any = (await query.execute()).rows.first()
        if ( info ) {
            this._owner = info.owner
            this._encoding = info.encoding_char
            this._lc_collate = info.datcollate
            this._lc_ctype = info.datctype
            this._tablespace = info.tablespace
            this._is_template = info.datistemplate
            this._allow_conn = info.datallowconn
            this._conn_limit = info.datconnlimit
        }
    }

    async tables(invalidate_cache: boolean = false) {
        if ( !this._table_cache || invalidate_cache ) {
            this._table_cache = await this.connection.tables(this.name)
            this._table_cache.each((table: Table) => table.set_database(this))
        }

        return this._table_cache
    }

    async table(name: string, invalidate_cache: boolean = false) {
        if ( !this._table_cache || invalidate_cache ) {
            this._table_cache = await this.connection.tables(this.name)
            this._table_cache.each((table: Table) => table.set_database(this))
        }

        return this._table_cache.firstWhere('name', '=', name)
    }

    public is_dirty() {
        return (
            (this._owner_override && this._owner_override !== this._owner)
            || (this._encoding_override && this._encoding_override !== this._encoding)
            || (this._lc_collate_override && this._lc_collate_override !== this._lc_collate)
            || (this._lc_ctype_override && this._lc_ctype_override !== this._lc_ctype)
            || (this._tablespace_override && this._tablespace_override !== this._tablespace)
            || (typeof this._is_template_override !== 'undefined' && this._is_template_override !== this._is_template)
            || (typeof this._allow_conn_override !== 'undefined' && this._allow_conn_override !== this._allow_conn)
            || (typeof this._conn_limit_override !== 'undefined' && this._conn_limit_override !== this._conn_limit)
            || this._rename
        )
    }

    public async exists() {
        return !!(await this.connection.database(this.name))
    }

    public async save() {
        if ( await this.exists() ) {
            const query = (new Builder).alter_database().name(this.name)

            if ( this._owner_override && this._owner_override !== this._owner ) {
                query.owner(this._owner_override)
            }

            if ( typeof this._allow_conn_override !== 'undefined' && this._allow_conn_override !== this._allow_conn ) {
                if ( this._allow_conn_override ) query.allow_connections()
                else query.disallow_connections()
            }

            if ( typeof this._conn_limit_override !== 'undefined' && this._conn_limit_override !== this._conn_limit ) {
                query.connection_limit(this._conn_limit_override)
            }

            if ( typeof this._is_template_override !== 'undefined' && this._is_template_override !== this._is_template ) {
                if ( this._is_template_override ) query.as_template()
                else query.not_as_template()
            }

            if ( this._rename ) {
                query.rename_to(this._rename)
            }

            if ( this._owner_override && this._owner_override !== this._owner ) {
                query.owner(this._owner_override)
            }

            if ( this._tablespace_override && this._tablespace_override !== this._tablespace ) {
                query.tablespace(this._tablespace_override)
            }

            if ( query.sql().trim().length < 1 ) return

            await query.execute_in_connection(this.connection)
        } else {
            const query = (new Builder).create_database()
                .name(this.name)

            if ( this._owner_override ) query.owner(this._owner_override)
            if ( this._is_template_override ) query.as_template()
            if ( this._encoding_override ) query.encoding(this._encoding_override)
            if ( this._lc_ctype_override ) query.lc_collate(this._lc_ctype_override)
            if ( this._lc_ctype ) query.lc_ctype(this._lc_ctype)
            if ( this._tablespace ) query.tablespace(this._tablespace)
            if ( !this._allow_conn_override && typeof this._allow_conn_override !== 'undefined' ) query.disallow_connections()
            if ( this._conn_limit_override && typeof this._conn_limit_override !== 'undefined' ) query.connection_limit(this._conn_limit_override)

            await query.execute_in_connection(this.connection)
        }
    }
}