import { MySQLClient } from '@p42/p42modules'
import { SimRepository } from '../../SimMaestro/simRepository.js'

function agentHashKey(template, agentId) {
    return(template.replace(/\[UID\]/g, agentId))
}

function parseJsonField(raw) {
    if(raw == null) return(null)
    if(typeof(raw) === 'object') return(raw)
    try { return(JSON.parse(raw)) }
    catch { return(null) }
}

function vectorsEqual(a, b) {
    for(const axis of ['x', 'y', 'z']) {
        if(a[axis] !== b[axis]) return(false)
    }
    return(true)
}

async function findSimulationFixture(ctx) {
    const { guiDatabase, simDatabase } = ctx.databases
    const rows = await MySQLClient.poolExecute(ctx.db, `
        SELECT u.usr_uuid AS user_uuid,
               BIN_TO_UUID(s.sim_uuid) AS simulation_uuid,
               BIN_TO_UUID(s.sim_root_kf_uuid) AS keyframe_id
        FROM \`${guiDatabase}\`.users u
        INNER JOIN \`${guiDatabase}\`.simowners o ON o.own_usr_id = u.usr_id
        INNER JOIN \`${simDatabase}\`.simulations s ON o.own_sim_uuid = s.sim_uuid
        INNER JOIN \`${simDatabase}\`.edited_kf_store ekfs ON ekfs.ekfs_ekf_uuid = s.sim_root_kf_uuid
        GROUP BY u.usr_uuid, s.sim_uuid, s.sim_root_kf_uuid
        HAVING COUNT(ekfs.ekfs_agent_id) > 0
        LIMIT 1
    `)

    if(!rows.length) {
        throw(new Error(
            'No simulation fixture found in MySQL (need user-owned sim with root keyframe agents). '
            + 'Pass --userUuid, --simulationUuid, --keyframeId explicitly, or use --guiDatabase / --simDatabase for a test DB.'
        ))
    }

    return({
        userUuid: rows[0].user_uuid,
        simulationUuid: rows[0].simulation_uuid,
        keyframeId: rows[0].keyframe_id,
    })
}

function waitForLifecycleEvent(ctx, eventType, timeoutMs) {
    return(new Promise((resolve, reject) => {
        const lifecyclePattern = ctx.config.maestro.lifecycle.arenaChannel
        const timer = setTimeout(() => {
            ctx.offArenaMessage(handler)
            reject(new Error(`Timeout waiting for ${eventType} on ${lifecyclePattern} (${timeoutMs}ms)`))
        }, timeoutMs)

        const handler = (msg, chan) => {
            if(!ctx.arenaCnx.matchesChan(chan, lifecyclePattern)) return
            if(msg.eventType !== eventType) return
            clearTimeout(timer)
            ctx.offArenaMessage(handler)
            resolve(msg)
        }

        ctx.onArenaMessage(handler)
    }))
}

export function configureYargs(yargsBuilder) {
    return(yargsBuilder.options({
        userUuid: {
            describe: 'User UUID to send STARTSIMULATION as (auto-discovered if omitted)',
            type: 'string',
        },
        simulationUuid: {
            describe: 'Simulation UUID (auto-discovered if omitted)',
            type: 'string',
        },
        keyframeId: {
            describe: 'Root keyframe UUID (auto-discovered if omitted)',
            type: 'string',
        },
        timeout: {
            describe: 'Milliseconds to wait for onYourMarks',
            default: 15000,
            type: 'number',
        },
    }))
}

export async function run(ctx) {
    const { log, argv, config, systemCnx, arenaCnx } = ctx
    const arenaStorage = config.gps?.arenaStorage ?? {
        agentHashKey: 'arena:agents:[UID]',
        agentsIndexKey: 'arena:agents',
    }

    log('action', 'Resolving simulation fixture from MySQL...')
    let userUuid = argv.userUuid
    let simulationUuid = argv.simulationUuid
    let keyframeId = argv.keyframeId

    if(!userUuid || !simulationUuid || !keyframeId) {
        const fixture = await findSimulationFixture(ctx)
        userUuid = userUuid ?? fixture.userUuid
        simulationUuid = simulationUuid ?? fixture.simulationUuid
        keyframeId = keyframeId ?? fixture.keyframeId
    }

    log('action', `User: ${userUuid}`)
    log('action', `Simulation: ${simulationUuid}`)
    log('action', `Keyframe: ${keyframeId}`)

    const simRepo = new SimRepository(ctx.db, ctx.databases, false)
    const access = await simRepo.validateSimulationAccess(userUuid, simulationUuid, keyframeId)
    if(!access.ok) throw(new Error(`Simulation access check failed: ${access.err}`))

    const agentsResult = await simRepo.loadKeyframeAgents(keyframeId)
    if(!agentsResult.ok) throw(new Error(`Failed to load keyframe agents: ${agentsResult.err}`))
    if(!agentsResult.agents.length) throw(new Error('Keyframe has no agents with valid GPS values'))

    log('success', `Loaded ${agentsResult.agents.length} agent(s) from MySQL`)

    const expectedById = new Map(agentsResult.agents.map(a => [a.id, a]))
    const lifecycleWait = waitForLifecycleEvent(ctx, 'onYourMarks', argv.timeout)

    const reqid = `maestro1-${Date.now()}`
    const actionsChan = config.maestro.maestroActionsChannel

    log('action', `Publishing STARTSIMULATION on ${actionsChan} (reqid=${reqid})...`)
    await systemCnx.redisPublish(actionsChan, {
        action: 'STARTSIMULATION',
        reqid,
        sender: userUuid,
        roles: ['*'],
        payload: {
            simulationUuid,
            keyframeId,
            infraId: null,
        },
    })

    log('action', `Waiting for onYourMarks on ${config.maestro.lifecycle.arenaChannel}...`)
    const lifecycleMsg = await lifecycleWait

    const payload = lifecycleMsg.payload ?? {}
    if(payload.simulationId !== simulationUuid) {
        throw(new Error(`onYourMarks simulationId mismatch: expected ${simulationUuid}, got ${payload.simulationId}`))
    }

    log('success', `Received onYourMarks for simulationId=${payload.simulationId}`)

    log('action', 'Reading arena store...')
    const indexIds = await arenaCnx.redisSmembers(arenaStorage.agentsIndexKey)
    const expectedIds = [...expectedById.keys()].sort()
    const actualIds = [...indexIds].sort()

    if(actualIds.length !== expectedIds.length) {
        throw(new Error(`Agent index count mismatch: expected ${expectedIds.length}, got ${actualIds.length}`))
    }

    for(let i = 0; i < expectedIds.length; i++) {
        if(actualIds[i] !== expectedIds[i]) {
            throw(new Error(`Agent index mismatch at ${i}: expected ${expectedIds[i]}, got ${actualIds[i]}`))
        }
    }

    log('success', `Arena agents index contains ${actualIds.length} agent(s)`)

    for(const agentId of expectedIds) {
        const key = agentHashKey(arenaStorage.agentHashKey, agentId)
        const hash = await arenaCnx.redisHgetall(key)
        const expected = expectedById.get(agentId)

        const position = parseJsonField(hash.position)
        const vector = parseJsonField(hash.vector)

        if(!position || !vector) {
            throw(new Error(`Agent ${agentId}: missing position or vector in arena hash ${key}`))
        }

        if(!vectorsEqual(position, expected.position)) {
            throw(new Error(`Agent ${agentId}: position mismatch (MySQL vs arena store)`))
        }

        if(!vectorsEqual(vector, expected.vector)) {
            throw(new Error(`Agent ${agentId}: vector mismatch (MySQL vs arena store)`))
        }

        log('success', `Agent ${agentId}: position and vector match MySQL`)
    }

    log('success', 'Arena store seeded correctly from MySQL (Maestro will stall waiting for readyToStart without GPS)')
}