import { AccesRights } from '../accesRights.js'
import { createMysqlPool } from '../mysqlClient.js'
import { SimRepository } from './simRepository.js'
import { ArenaGroom } from './arenaGroom.js'
import { MaestroState } from './orchestrationState.js'

export class maestroServer {

    constructor(configHelper, allRediscnx, debug) {
        this.configHelper = configHelper
        this.maestroConfig = configHelper.config
        this.allRediscnx = allRediscnx
        this.debug = debug
        this.accessRights = new AccesRights(this.maestroConfig, debug)
        this.arenaCnx = null
        this.arenaCnxs = []
        this.systemCnx = null
        this.db = null
        this.simRepo = null
        this.arenaGroom = null
        this.orchestrationState = MaestroState.IDLE
        this.simulationId = null
        this.agentIds = []
        this.readyGods = new Map()
        this.readyQuorumResolve = null
        this.readyQuorumTimer = null
    }

    getMaestroSettings() {
        const maestro = this.maestroConfig.maestro ?? {}
        return({
            senderId: maestro.senderId ?? 'maestro',
            lifecycle: {
                arenaChannel: maestro.lifecycle?.arenaChannel ?? 'arena:lifecycle',
                godsReadyChannel: maestro.lifecycle?.godsReadyChannel ?? 'arena:gods:ready',
            },
            expectedGods: maestro.expectedGods ?? ['gps'],
            readyTimeoutMs: maestro.readyTimeoutMs ?? 30000,
        })
    }

    getArenaStorageSettings() {
        const gps = this.maestroConfig.gps ?? {}
        return({
            agentHashKey: gps.arenaStorage?.agentHashKey ?? 'arena:agents:[UID]',
            agentsIndexKey: gps.arenaStorage?.agentsIndexKey ?? 'arena:agents',
        })
    }

    isIdle() {
        return(this.orchestrationState === MaestroState.IDLE)
    }

    isLive() {
        return(this.orchestrationState === MaestroState.LIVE)
    }

    async init() {
        const mysqlCfg = this.maestroConfig.mysql
        if(!mysqlCfg) {
            console.error('[Maestro] Missing mysql config')
            return(false)
        }
        this.db = await createMysqlPool(mysqlCfg)
        this.simRepo = new SimRepository(this.db, this.debug)
        if(this.debug) console.log('[Maestro] MySQL pool ready')
        return(true)
    }

    refreshArenaGroom() {
        if(this.arenaCnx) {
            this.arenaGroom = new ArenaGroom(
                this.arenaCnx,
                this.getArenaStorageSettings(),
                this.debug
            )
        }
    }

    wireSystemConnexion(cnx) {
        cnx.maestroSrv = this
        cnx.accessRights = this.accessRights
        cnx.reloadAccessRights = () => this.reloadAccessRights()
        cnx.getAccessRights = () => this.getAccessRights()
        if(!this.systemCnx || cnx.redisConfig.role === 'primary') {
            this.systemCnx = cnx
        }
    }

    wireArenaConnexion(cnx) {
        cnx.maestroSrv = this
        this.arenaCnxs.push(cnx)
        if(!this.arenaCnx || cnx.redisConfig.role === 'primary') {
            this.arenaCnx = cnx
            this.refreshArenaGroom()
        }
    }

    resetOrchestration() {
        this.orchestrationState = MaestroState.IDLE
        this.simulationId = null
        this.agentIds = []
        this.readyGods.clear()
        this.clearReadyQuorumWait()
    }

    clearReadyQuorumWait() {
        if(this.readyQuorumTimer) {
            clearTimeout(this.readyQuorumTimer)
            this.readyQuorumTimer = null
        }
        this.readyQuorumResolve = null
    }

    completeReadyQuorum(result) {
        const resolve = this.readyQuorumResolve
        this.clearReadyQuorumWait()
        if(typeof(resolve) === 'function') resolve(result)
    }

    waitForReadyQuorum() {
        const { readyTimeoutMs } = this.getMaestroSettings()
        return(new Promise(resolve => {
            this.readyQuorumResolve = resolve
            this.readyQuorumTimer = setTimeout(() => {
                this.completeReadyQuorum({
                    ok: false,
                    err: `Timeout waiting for readyToStart (${readyTimeoutMs}ms)`,
                })
            }, readyTimeoutMs)
        }))
    }

    onReadyToStart(msg) {
        if(this.orchestrationState !== MaestroState.PREPARING) return

        const payload = msg.payload ?? {}
        if(payload.simulationId !== this.simulationId) return

        const sender = msg.sender
        const { expectedGods } = this.getMaestroSettings()
        if(!expectedGods.includes(sender)) {
            if(this.debug) console.warn(`[Maestro] Ignoring readyToStart from unexpected sender: ${sender}`)
            return
        }

        if(!payload.success) {
            this.completeReadyQuorum({
                ok: false,
                err: payload.err ?? `Participant ${sender} failed prepare`,
            })
            return
        }

        this.readyGods.set(sender, payload)
        if(this.debug) console.log(`[Maestro] readyToStart from ${sender} (${this.readyGods.size}/${expectedGods.length})`)

        for(const god of expectedGods) {
            if(!this.readyGods.has(god)) return
        }

        this.completeReadyQuorum({ ok: true })
    }

    async publishLifecycle(eventType, payload) {
        if(!this.arenaCnx) throw new Error('No arena Redis connection')
        const { arenaChannel, senderId } = this.getMaestroSettings().lifecycle
        await this.arenaCnx.redisPublish(arenaChannel, {
            eventType,
            sender: senderId,
            payload,
        })
        if(this.debug) console.log(`[Maestro] Published ${eventType} simulationId=${payload.simulationId}`)
    }

    async startSimulation(userUuid, payload) {
        if(!this.simRepo) return({ ok: false, err: 'Database not initialized' })
        if(!this.arenaGroom) return({ ok: false, err: 'No arena Redis connection' })
        if(!this.isIdle()) return({ ok: false, err: 'A simulation is already in progress' })

        const simulationUuid = payload?.simulationUuid
        const keyframeId = payload?.keyframeId
        const infraId = payload?.infraId ?? null

        const access = await this.simRepo.validateSimulationAccess(userUuid, simulationUuid, keyframeId)
        if(!access.ok) return(access)

        const agentsResult = await this.simRepo.loadKeyframeAgents(keyframeId)
        if(!agentsResult.ok) return(agentsResult)

        await this.arenaGroom.clearArena()
        await this.arenaGroom.seedAgents(agentsResult.agents)

        this.simulationId = simulationUuid
        this.agentIds = agentsResult.agents.map(a => a.id)
        this.readyGods.clear()
        this.orchestrationState = MaestroState.PREPARING

        const lifecyclePayload = {
            simulationId: this.simulationId,
            agentIds: this.agentIds,
            keyframeId,
            infraId,
        }

        const readyWait = this.waitForReadyQuorum()

        await this.publishLifecycle('onYourMarks', lifecyclePayload)

        const quorum = await readyWait
        if(!quorum.ok) {
            await this.arenaGroom.clearArena()
            this.resetOrchestration()
            return(quorum)
        }

        await this.publishLifecycle('bigBang', {
            simulationId: this.simulationId,
            agentIds: this.agentIds,
        })

        this.orchestrationState = MaestroState.LIVE
        if(this.debug) console.log(`[Maestro] LIVE simulationId=${this.simulationId}`)

        return({
            ok: true,
            simulationId: this.simulationId,
            keyframeId,
            infraId,
            agentIds: this.agentIds,
        })
    }

    async stopSimulation(userUuid, payload) {
        if(!this.simRepo) return({ ok: false, err: 'Database not initialized' })
        if(!this.arenaGroom) return({ ok: false, err: 'No arena Redis connection' })

        const simulationUuid = payload?.simulationUuid
        const access = await this.simRepo.validateSimulationOwner(userUuid, simulationUuid)
        if(!access.ok) return(access)

        if(this.simulationId && this.simulationId !== simulationUuid) {
            return({ ok: false, err: 'Another simulation is active' })
        }

        await this.arenaGroom.clearArena()
        this.resetOrchestration()

        if(this.debug) console.log(`[Maestro] Stopped simulationId=${simulationUuid}`)

        return({ ok: true, simulationId: simulationUuid })
    }

    async reloadAccessRights() {
        await this.configHelper.refreshAccessRights()
        this.maestroConfig.accessRights = this.configHelper.config.accessRights
        this.accessRights.refreshAccessRights(this.maestroConfig)
    }

    getAccessRights() {
        return(this.maestroConfig.accessRights)
    }

}