import {takeEvery} from 'redux-saga';
import {call, put, select} from 'redux-saga/effects';
import Apis from 'shared/api_client/ApiInstances'
import {Set, Map, fromJS, List} from 'immutable'
import {PrivateKey} from 'shared/ecc'
import user from 'app/redux/User'
import g from 'app/redux/GlobalReducer'

// operations that require only posting authority
const postingOps = Set(`vote, comment, delete_comment, custom_json`.trim().split(/,\s*/))

export const authWatches = [
    watchForAuth
]

function* watchForAuth() {
    yield* takeEvery('user/ACCOUNT_AUTH_LOOKUP', accountAuthLookup);
}

export function* accountAuthLookup({payload: {account, private_keys, login_owner_pubkey}}) {
    account = fromJS(account)
    private_keys = fromJS(private_keys)
    // console.log('accountAuthLookup', account.name)
    const stateUser = yield select(state => state.user)
    let keys
    if (private_keys)
        keys = private_keys
    else
        keys = stateUser.getIn(['current', 'private_keys'])

    if (!keys || !keys.has('posting_private')) return
    const toPub = k => k ? k.toPublicKey().toString() : '-'
    const posting = keys.get('posting_private')
    const active = keys.get('active_private')
    const memo = keys.get('memo_private')
    const auth = {
        posting: posting ? yield authorityLookup(
            {pubkeys: Set([toPub(posting)]), authority: account.get('posting'), authType: 'posting'}) : 'none',
        active: active ? yield authorityLookup(
            {pubkeys: Set([toPub(active)]), authority: account.get('active'), authType: 'active'}) : 'none',
        owner: 'none',
        memo: account.get('memo_key') === toPub(memo) ? 'full' : 'none'
    }
    const accountName = account.get('name')
    const pub_keys_used = {posting: toPub(posting), active: toPub(active), owner: login_owner_pubkey};
    yield put(user.actions.setAuthority({accountName, auth, pub_keys_used}))
}

/**
    @arg {object} data
    @arg {object} data.authority Immutable Map blockchain authority
    @arg {object} data.pubkeys Immutable Set public key strings
    @return {string} full, partial, none
*/
function* authorityLookup({pubkeys, authority, authType}) {
    return yield call(authStr, {pubkeys, authority, authType})
}

function* authStr({pubkeys, authority, authType, recurse = 1}) {
    const t = yield call(threshold, {pubkeys, authority, authType, recurse})
    const r = authority.get('weight_threshold')
    return t >= r ? 'full' : t > 0 ? 'partial' : 'none'
}

export function* threshold({pubkeys, authority, authType, recurse = 1}) {
    if (!pubkeys.size) return 0
    let t = pubkeyThreshold({pubkeys, authority})
    const account_auths = authority.get('account_auths')
    const aaNames = account_auths.map(v => v.get(0), List())
    if (aaNames.size) {
        const aaAccounts = yield call(Apis.db_api, 'get_accounts', aaNames)
        const aaThreshes = account_auths.map(v => v.get(1), List())
        for (let i = 0; i < aaAccounts.size; i++) {
            const aaAccount = aaAccounts.get(i)
            t += pubkeyThreshold({authority: aaAccount.get(authType), pubkeys})
            if (recurse <= 2) {
                const auth = yield call(authStr,
                    {authority: aaAccount, pubkeys, recurse: ++recurse})
                if (auth === 'full') {
                    const aaThresh = aaThreshes.get(i)
                    t += aaThresh
                }
            }
        }
    }
    return t
}

function pubkeyThreshold({pubkeys, authority}) {
    let available = 0
    const key_auths = authority.get('key_auths')
    key_auths.forEach(k => {
        if (pubkeys.has(k.get(0))) {
            available += k.get(1)
        }
    })
    return available
}

export function* findSigningKey({opType, username, password}) {
    let authTypes
    if (postingOps.has(opType))
        authTypes = 'posting, active'
    else
        authTypes = 'active, owner'
    authTypes = authTypes.split(', ')

    const currentUser = yield select(state => state.user.get('current'))
    const currentUsername = currentUser && currentUser.get('username')

    username = username || currentUsername
    if (!username) return null

    const private_keys = currentUsername === username ? currentUser.get('private_keys') : Map()

    let account = yield select(state => state.global.getIn(['accounts', username]))
    if (!account) {
        [account] = yield call(Apis.db_api, 'get_accounts', [username])
        if (!account) throw new Error('Account not found')
        account = fromJS(account)
        yield put(g.actions.receiveAccount({account}))
    }
    for (const authType of authTypes) {
        let private_key
        if (password) {
            try {
                private_key = PrivateKey.fromWif(password)
            } catch (e) {
                private_key = PrivateKey.fromSeed(username + authType + password)
            }
        } else {
            if(private_keys)
                private_key = private_keys.get(authType + '_private')
        }
        if (private_key) {
            const pubkey = private_key.toPublicKey().toString()
            const pubkeys = Set([pubkey])
            const authority = account.get(authType)
            const auth = yield call(authorityLookup, {pubkeys, authority, authType})
            if (auth === 'full') return private_key
        }
    }
    return null
}

// function isPostingOnlyKey(pubkey, account) {
//     // TODO Support account auths
//     // yield put(g.actions.authLookup({account, pubkeys: pubkey})
//     // authorityLookup({pubkeys, authority: Map(account.posting), authType: 'posting'})
//     for (const p of account.posting.key_auths) {
//         if (pubkey === p[0]) {
//             if (account.active.account_auths.length || account.owner.account_auths.length) {
//                 console.log('UserSaga, skipping save password, account_auths are not yet supported.')
//                 return false
//             }
//             for (const a of account.active.key_auths)
//                 if (pubkey === a[0]) return false
//             for (const a of account.owner.key_auths)
//                 if (pubkey === a[0]) return false
//             return true
//         }
//     }
//     return false
// }
