const Schmervice = require('@hapipal/schmervice')
const haversine = require('haversine')
const config = require('../../db/data-generator/config.json')

const _isScorableResponse = res_key_id => {
    let isScorable = false
    if(config.resKeys.includes(res_key_id)) {
        isScorable = true
    }
    return isScorable
}

const scoreResponses = (seeker, potentialMatch, prescoreLookup) => {
    if (seeker.responses.length != potentialMatch.responses.length)
        return {
            error: `complete responses for profile: ${seeker.profile_id} unqeual to profile: ${potentialMatch.profile_id} | ${seeker.responses.length}:${potentialMatch.responses.length}`,
        }

    const aRes = seeker.responses.filter(
        res =>  _isScorableResponse(res.response_key_id)
    )
    const bRes = potentialMatch.responses.filter(
        res =>  _isScorableResponse(res.response_key_id)
    )

    const composite = []
    while (aRes.length + bRes.length > 0) {
        const mKey = resList => {
            let el = resList.shift()
            let pair = el.val
            el = resList.shift()
            return `${pair}:${el.val}`
        }
        composite.push(prescoreLookup[mKey(aRes)][mKey(bRes)])
    }
    return {
        total: Math.round(composite.reduce((a, b) => a + b) / composite.length),
        aspects: composite,
    }
}
const filterByDistance = (profileList, max) => {
    return profileList.filter(profile => {
        const profileDistance = Math.floor(parseFloat(profile.distance) * 100)
        const adjustedMaxDistance = Math.floor(parseFloat(max) * 100)
        return profileDistance <= adjustedMaxDistance
    })
}
const scoreAll = (profileList, userProfile, prescoreLookup) => {
    return profileList.map(profile => {
        return {
            // Uncomment to return the whole profile
            // ...profile,
            profile_id: profile.profile_id,
            score: scoreResponses(userProfile, profile, prescoreLookup),
            distance: profile.distance,
        }
    })
}
/**
 * Grab the zip code string
 */
const getZipCodeFromProfile = profile => {
    // There should only be one zip code entry per profile
    let zipRes = profile.responses.find(
        res => res.response_key_id == 7
    )
    return zipRes.val
}

const makeScoreLookup = (aspects, labels) => {
    const labelLookup = {}
    labels.forEach(label => (labelLookup[label.aspect_id] = label))

    const scoreLookup = {}
    aspects.forEach(aspect => {
        const key = labelLookup[aspect.aspect_id]
        scoreLookup[`${key.a}:${key.b}`] = {}
        Object.keys(aspect).forEach(aspect_id => {
            if (!labelLookup[aspect_id]) return
            const comp = labelLookup[aspect_id]
            const score = aspect[aspect_id]
            scoreLookup[`${key.a}:${key.b}`][`${comp.a}:${comp.b}`] = score
        })
    })
    return scoreLookup
}

/**
 * Class to hold our retrieved profile information
 * in a convenient wrapper
 * !: This needs to match the responseSchema in profiles.js
 */
class CompleteProfile {
    constructor(profile, type) {
        this.user_id = profile.user_id // int user_id
        this.profile_id = profile.profile_id // int profile_id
        this.user_name = profile.user.user_name // string user_name
        this.responses = []
        this.tags = profile.tags // [] of all tags
        this.user_type = type

        // TODO: generalize this for multiple images, and languages
        this.profile_description = ''
        this.profile_media = []
        this.profile_languages = []
        this.profile_prefs = {}
        if (profile?.responses?.length) {
            // [] of all "profile" responses
            this.responses = profile.responses
            // image, language, duration, presence, blurb, urgency, role, pronouns, distance
            const prefs = ['presence', 'duration', 'zipcode']
            prefs.forEach(pref => {
                this.profile_prefs[pref] = this.responses.filter(
                    r => r.response_key_prompt === pref
                )[0]
            })
            this.profile_description = this.responses.filter(r=> r.response_key_prompt === 'blurb')[0]
            this.profile_media = this.responses.filter(r => r.response_key_prompt === 'image')
            this.profile_languages = this.responses.filter(r => r.response_key_prompt === 'language')
        }
    }
}

module.exports = class ProfileService extends Schmervice.Service {
    constructor(...args) {
        super(...args)
        this.scoreLookup = {}
        this.tagLookup = {}
        // this.responseKeyLookup = ResponseKey.query()
    }
    async _setScoreLookup() {
        if (!Object.keys(this.scoreLookup).length) {
            const { Aspect, AspectLabel } = this.server.models()
            const aspects = await Aspect.query()
            const labels = await AspectLabel.query()
            this.scoreLookup = makeScoreLookup(aspects, labels)
        }
    }
    async _setTagLookup() {
        if (!Object.keys(this.tagLookup).length) {
            const { Tag } = this.server.models()
            const allTagDescriptions = await Tag.query()
            allTagDescriptions.forEach(
                desc =>
                    (this.tagLookup[desc.tag_id] = {
                        description: desc.tag_description,
                        category: desc.tag_category,
                    }),
            )
        }
    }
    /**
     * Internal method to get list of profile_ids for this user
     * @param {number} userId
     * @returns {Array} List of all profile_ids for user
     */
    async _getProfileIdsForUserId(userId) {
        const { Profile } = this.server.models()

        /** Grab every Profile associated with this id */
        const allProfiles = await Profile.query().where('user_id', userId)

        /** Copy a list of the just the Profiles */
        const profileIdsToGrab = allProfiles.map(profile => profile.profile_id)

        /** Uncomment to dedupe the list just in case */
        return [...new Set(profileIdsToGrab)]
    }

    async getProfile(profileId) {
        const { Profile } = this.server.models()
        await this._setTagLookup()

        const matchingProfile = await Profile.query()
            .where('profile_id', profileId)
            .first()
            .withGraphFetched('tags')
            .withGraphFetched('responses')
            .withGraphFetched('user')

        if(matchingProfile?.tags.length){
            matchingProfile.tags = matchingProfile.tags.map(
                tag => this.tagLookup[tag.tag_id],
            )
        }

        return new CompleteProfile(matchingProfile)
    }

    async getCompleteProfilesFor(userId, type) {
        const { Profile } = this.server.models()
        await this._setTagLookup()

        const dedupedProfileIds = await this._getProfileIdsForUserId(userId)

        const profilesEntries = await Profile.query()
            .whereIn('profile_id', dedupedProfileIds)
            .withGraphFetched('tags')
            .withGraphFetched('responses')
            // CHECKTHIS: Added this because we added user.user_name to CompleteProfile
            // so without this, we get undefined user_name
            .withGraphFetched('user')

        profilesEntries.forEach(profile => {
            profile.tags = profile.tags.map(tag => this.tagLookup[tag.tag_id])
        })

        //** Get responses asociated with each profile_id */
        return profilesEntries.map(profile => {
            return new CompleteProfile(profile, type)
        })
    }

    async getProfilesFor(profileIdArray, type, includeResponses = true) {
        const { Profile } = this.server.models()
        await this._setScoreLookup()
        await this._setTagLookup()

        // profilesEntries is profiles in dataaspect_labelsbase row order
        const profilesEntries = await Profile.query()
            .whereIn('profile_id', profileIdArray)
            .withGraphFetched('tags')
            .withGraphFetched('responses')
            .withGraphFetched('user')

        // taking the info from profilesEntries
        // to repack into completeProfiles
        // in same order as profileIdArray
        const completeProfiles = []
        profileIdArray.forEach(pid => {
            profilesEntries.forEach(entry => {
                if (entry.profile_id == pid) {
                    const complete = new CompleteProfile(entry, type)
                    if (!includeResponses) {
                        delete complete['responses']
                    }
                    if (entry?.tags?.length) {
                        complete.tags = entry.tags.map(
                            tag => this.tagLookup[tag.tag_id],
                        )
                    }
                    completeProfiles.push(complete)
                }
            })
        })
        return completeProfiles
    }

    /**
     * Save responses in a profile
     * @param {number} userId
     * @param {Array} responses
     * @returns {object}
     */
    async saveResponsesCreateProfileFor(userId, responses, txn) {
        const { Profile, Response } = this.server.models()

        const profile = await Profile.query(txn).insert({
            user_id: userId,
        })
        for (const responseToSave of responses) {
            /**
             * Convert indexes to actual score values
             * Using using the input and converting to index
             * of the generated possible prescore array in config
             * DUPLICATE:See saveResponseForProfile() line 343
             */ 
            let convertedResponse = responseToSave
            if(_isScorableResponse(responseToSave.response_key_id)) {
                // Convert -3 to 0, 0 to 3, 3 to 6
                const offset = (config.scoreVals.length - 1) / 2
                const indexFromInput = parseInt(responseToSave.val) + offset
                convertedResponse.val = config.scoreVals[indexFromInput].toString()
            }

            const responseInfo = {
                profile_id: profile.id,
                response_key_id: convertedResponse.response_key_id,
                val: convertedResponse.val,
            }
            await Response.query(txn).insert(responseInfo)
        }
        //** Work around for HAPI returning profile_id as id */
        return { user_id: profile.user_id, profile_id: profile.id }
    }

    /** Update responses in place
     * @param {number} profileId
     * @param {Array} responses
     * @returns {Array} updated responses
     */
    async updateResponsesInProfile(profileId, responses, txn) {
        const { Response } = this.server.models()
        for (const responseToSave of responses) {
            await Response.query(txn)
                .update({
                    response_id: responseToSave.response_id,
                    profile_id: responseToSave.profile_id,
                    response_key_id: responseToSave.response_key_id,
                    val: responseToSave.val,
                })
                .where({
                    profile_id: profileId,
                })
                .where({
                    response_id: responseToSave.response_id,
                })
        }
        return await Response.query(txn).where({
            profile_id: profileId,
        })
    }

    /** Add response
     * @param {Object} response to save
     * @returns {null} updated responses
     * @returns {Array} updated responses
     */
    async saveResponseForProfile(profileId, responseToSave) {
        const { Response } = this.server.models()
        let allResponses = await Response.query().where({
            profile_id: profileId,
        })

        // Delete matches
        // ?:Maybe bad idea
        const matchingResponses = allResponses.filter(
            response =>
                response.response_key_id == responseToSave.response_key_id,
        )
        if (matchingResponses.length > 0) {
            const alreadyAnswered = matchingResponses.map(
                matchingRes => matchingRes.response_key_id
            )
            await Response.query()
                .where({ profile_id: profileId })
                .delete()
                .whereIn('response_key_id', alreadyAnswered)
        }

        /**
         * Convert indexes to actual score values
         * Using using the input and converting to index
         * of the generated possible prescore array in config
         */ 
        let convertedResponse = responseToSave
        if(_isScorableResponse(responseToSave.response_key_id)) {
            // Convert -3 to 0, 0 to 3, 3 to 6
            const offset = (config.scoreVals.length - 1) / 2
            const indexFromInput = parseInt(responseToSave.val) + offset
            convertedResponse.val = config.scoreVals[indexFromInput].toString()
        }

        await Response.query().insert(convertedResponse)
        return allResponses
    }

    /**
     * Delete a profile
     * @param {number} userId
     * @param {number} profileId
     * @returns
     */
    async deleteProfile(userId, profileId) {
        const { Profile } = this.server.models()

        const dedupedGroupings = await this._getProfileIdsForUserId(userId)

        /** Do NOTHING if NOT in Grouping */
        if (!dedupedGroupings.includes(profileId)) return

        return await Profile.query().delete().where('profile_id', profileId)
    }

    /**
     * Score a profile
     * @param {number} profileId
     * @returns {Array} Ordered and scored Profiles
     */
    async scoreProfilesFor(profileId, maxDistance, distanceUnit) {
        const { Profile } = this.server.models()

        await this._setScoreLookup()

        // Our User Profile to score for
        const userProfile = await Profile.query()
            .findOne('profile_id', profileId)
            .withGraphFetched('responses')
            .withGraphFetched('user')
        
        // Move unneeded responses
        const userZip = getZipCodeFromProfile(userProfile)

        // Find all Profiles that are NOT of our userProfile.type
        // ie. If userProfile.type == seeker, then find: poster
        let profileIdsOfOppositeType = await Profile.query()
            .withGraphFetched('responses')
            .withGraphFetched('user')

        // TODO: Let Objection optimize this
        const isPosterOpposite = userProfile.user.is_poster == 1 ? 0 : 1
        profileIdsOfOppositeType = profileIdsOfOppositeType.filter(profile => {
            return profile.user.is_poster == isPosterOpposite
        }).filter(profile => {
            // Only include profiles that included zipcode response
            return getZipCodeFromProfile(profile) ? true : false
        })
        
        const profilePlusDistance = await Promise.all(
            profileIdsOfOppositeType.map(async profile => {
                const targetZip = getZipCodeFromProfile(profile)

                if (!userZip || !targetZip)
                    return { ...profile, distance: [9999, distanceUnit] }

                const distance = await this._compareDistance(
                    userZip,
                    targetZip,
                    distanceUnit,
                )
                return {
                    ...profile,
                    distance: [distance.toFixed(2), distanceUnit],
                }
            }),
        )
        const distanceFilteredProfiles = filterByDistance(
            profilePlusDistance,
            maxDistance,
        )
        const scoredProfilesWithDistance = scoreAll(
            distanceFilteredProfiles,
            userProfile,
            this.scoreLookup,
        )

        // Order by score
        return scoredProfilesWithDistance.sort(
            (a, b) => b.score.total - a.score.total,
        )
    }

    /**
     * Use the db for zipcode info
     * @param {string} zipCode
     * @param {object}
     */
    async _latLonForZip(zipCode) {
        const { ZipCode } = this.server.models()

        const zipInfo = await ZipCode.query().findOne(
            'zip_code_id',
            parseInt(zipCode),
        )
        if (!zipInfo) {
            console.error('zip:', zipCode)
        }

        return {
            latitude: parseFloat(zipInfo.latitude),
            longitude: parseFloat(zipInfo.longitude),
        }
    }
    /**
     * Get the distance between two zipcodes
     * using the haversine formula
     * @param {string} start_zip
     * @param {string} end_zip
     * @param {number} distance in miles
     */
    async _compareDistance(start_zip, end_zip, distanceUnit) {
        if (!start_zip || !end_zip || isNaN(start_zip) || isNaN(end_zip)) return

        const start = await this._latLonForZip(start_zip)
        const end = await this._latLonForZip(end_zip)

        return haversine(start, end, { unit: distanceUnit })
    }
}