#!/usr/bin/env bash
VERSION="1.0.0"
CONFIG_DIR="$HOTPOCKET_CONFIG_DIR"
set -u
set +H

# This will be removed, dont rely on it
[ -z "$CONFIG_DIR" ] && echo "main: HOTPOCKET_CONFIG_DIR is not defined, assuming working directory. This is potentially unsafe"
[ -z "$CONFIG_DIR" ] && CONFIG_DIR="$PWD"

SCHEMA_DIR="$CONFIG_DIR/scripts/schema"
CONFIGD_DIR="$CONFIG_DIR/config.d"
IGNORED_FILE="$CONFIG_DIR/ignored.txt"

echo "main: Running as $(whoami). Version $VERSION. Directory at $CONFIG_DIR"
die () { echo "$@" 1>&2; exit 1; }
stripCtrlChars () { sed 's/\x1b/\\x1b/g' /dev/stdin; return $?; }

[ -d "$CONFIG_DIR" ]   || die "main: No hotpocket directory defined! See readme."
[ -d "$SCHEMA_DIR" ]   || die "main: No schema directory defined! See readme."
[ -d "$CONFIGD_DIR" ]  || die "main: No config.d directory defined! See readme."
[ -f "$IGNORED_FILE" ] || die "main: No ignored.txt exists! You'll need to create one that $(whoami) can write to."

str_startswith () {
    # str_startsswith: prefix string
    local alen
    local blen
    local end
    alen=${#1}
    blen=${#2}

    if [ "$alen" -gt "$blen" ]; then
        return 1
    else
        if [ "$1" == "${2:0:$alen}" ]; then
            return 0
        else
            return 1
        fi
    fi
}

str_endswith () {
    # str_endswith: affix string
    local alen
    local blen
    local end
    alen=${#1}
    blen=${#2}

    if [ "$alen" -gt "$blen" ]; then
        return 1
    else
        end=$((blen - alen))
        if [ "$1" == "${2:$end:$alen}" ]; then
            return 0
        else
            return 1
        fi
    fi
}


# Merge all files in config.d/ 
createConfig () {
    # createConfig:
    local filepath
    local filebase
    local json
    local code
    local config
    config="{}"

    for filepath in "$CONFIGD_DIR/"*; do
        filebase="$(basename "$filepath")"
        if [ -d "$filepath" ]; then
            echo "createConfig: Ignoring $filebase, Is a directory." 1>&2
        elif str_startswith "~" "$filebase" || str_endswith "~" "$filebase"; then
            echo "createConfig: Ignoring $filebase. Is a temporary file!" 1>&2
        elif str_startswith "." "$filebase"; then
            echo "createConfig: Ignoring $filebase. Is a hidden file!" 1>&2
        elif str_endswith ".yml" "$filebase" || str_endswith ".yaml" "$filebase" || str_endswith ".json" "$filebase"; then
            json="$(yq . "$filepath" -c)"
            code="$?"
            if [ $code -eq 0 ]; then
                config="$(jq --argjson a "$config" --argjson b "$json" \
                  '$a * $b * {
policy_rooms: ($a.policy_rooms + $b.policy_rooms),
actions: ($a.actions + $b.actions)
}' -nc)" || die "createConfig: Failed to merge $filebase with in-memory config. Exited with code $?"
            else
                echo "createConfig: Failed to load $filebase. Exited with code $code" 1>&2
                exit $code
            fi
        else
            echo "createConfig: Ignoring $(basename "$filebase")." 1>&2
        fi
    done
    #jq . 1>&2 <<< "$config"
    jq . -c <<< "$config"
}

CONFIG="$(createConfig)" || die "main: Failed to load config.d! Exited with $?"
yajsv -q -s "$SCHEMA_DIR/config.yaml" /dev/stdin <<< "$CONFIG" || die "main: Failed to load config.yaml! Defined config does not validate against schema"

BASE_URL="$(jq '.base_url' -r <<< "$CONFIG")" || die "main: Failed to load config.yaml! Failed to read base_url"
SYNAPSE_BASE_URL="$(jq '.synapse_base_url' -r <<< "$CONFIG")" || die "main: Failed to load config.yaml! Failed to read synapse_base_url"
KEYRING_FILE="$(jq '.keyring' -r <<< "$CONFIG")" || die "main: Failed to load config.yaml! Failed to read keyring"
KEYRING_FILE="$(realpath "$(realpath --relative-to="$CONFIG_DIR" "$KEYRING_FILE")")"

[ -f "$KEYRING_FILE" ] || die "main: Defined keyring does not exist! Should exist at $KEYRING_FILE"

HAS_AUDIT_ROOM=""; jq -e '.audit_room | type == "string"' 1>/dev/null <<< "$CONFIG" && HAS_AUDIT_ROOM="1"
DRY_RUN=""; jq -e '.dry_run' 1>/dev/null <<< "$CONFIG" && DRY_RUN="1"

ACTIONS="$(jq .actions -c <<< "$CONFIG")" || die "main: Failed to load config.yaml! Failed to read actions"
ACCESS_TOKEN="$(jq '.access_token' -r <<< "$CONFIG")" || die "main: Failed to read access_token!"
USER_ID="$(jq '.user_id' -r <<< "$CONFIG")" || die "main: Failed to read user_id!"
TOPICS="$(yq -c . "$SCHEMA_DIR/topics.yaml")" || die "main: Failed to load topics!"

[ -n "$DRY_RUN" ] && echo "main: This is a dry run, any actions will fail!" 1>&2

readonly CONFIG
readonly ACTIONS
readonly ACCESS_TOKEN
readonly TOPICS
readonly USER_ID
readonly DRY_RUN

fetchRoomState () {
    # fetchRoomState: room_id
    local room_id
    room_id="$(jq '@uri' -Rr <<< "$1")" || return 1
    curl -sf -H "Authorization: Bearer $ACCESS_TOKEN" "$BASE_URL/client/r0/rooms/$room_id/state"
    return $?
}

fetchRoomPolicies () {
    # fetchRoomPolicies: room_id
    local states
    states="$(fetchRoomState "$1")" || return 1
    jq '[ .[] | select(.type == "club.glowers.policy.rule.collection") ]' -c <<< "$states"
    return $?
}

arrayIndexList () {
    # arrayIndexList: array
    local length
    length="$(jq 'length' -r <<< "$1")"
    if [ -n "$length" ]; then
        seq 1 "$length"
    fi
}

# satan
# TODO: Rewrite this fucking abomination as a jq filter
arrayAndIncludes () {
    # arrayAndIncludes: Array<String> Array<String>
    local bset
    local aset_index ; local a
    local bset_index ; local b
    bset="$(arrayIndexList "$2")"

    for aset_index in $(arrayIndexList "$1"); do
        a="$(jq ".[$((aset_index-1))]" -rc <<< "$1")"
        for bset_index in $bset; do
            b="$(jq ".[$((bset_index-1))]" -rc <<< "$2")"
            if [ "$a" == "$b" ]; then
                echo "$a"
                return 0
            fi
        done
    done
    return 1
}

# shellcheck disable=SC2155
genIgnorefileLine () {
    # genIgnorefileLine: state
    local room_id="$(jq .room_id -r <<< "$1")"
    local state_key="$(jq .state_key -r <<< "$1")"
    echo "$room_id	$state_key"
}

checkPolicyIgnored () {
    # checkPolicyIgnored: state
    grep -Fx "$(genIgnorefileLine "$1")" "$IGNORED_FILE" 1>/dev/null # || return 0
}

checkSignature () {
    # checkSignature: state
    local content
    local signature
    local mask
    local wd
    local code

    content="$(jq '.content | { rules: .rules, signature: null }' -c <<< "$1")" || return 1
    signature="$(jq .content.signature -r <<< "$1")" || return 2

    mask="$(umask)"
    umask 0077
    wd="$(mktemp -d)" || return 3
    echo "$signature" > "$wd/content.json.sig"
    echo "$content" > "$wd/content.json"

    umask "$mask"

    gpg --no-default-keyring --keyring "$KEYRING_FILE" --verify "$wd/content.json.sig"
    code="$?"
    if [ "$code" != "0" ]; then
        echo "checkSignature: Exception when verifying policy signature. Exit code: $code" 1>&2
        rm "$wd/content.json.sig" "$wd/content.json"
        rmdir "$wd"
        return 4
    fi

    rm "$wd/content.json.sig" "$wd/content.json"
    rmdir "$wd"
    return 0
}

checkPolicyAgainstSchema () {
    # checkPolicyAgainstSchema: policy
    yajsv -q -s "$SCHEMA_DIR/policy.yaml" /dev/stdin <<< "$(jq .content -c <<< "$1")"
}

oneOfTagsAsArray () {
    # oneOfTagsAsArray: policy
    jq 'if (.tag | type == "string") then [.tag] else if (.tags | type == "array") then .tags else [] end end' -c < /dev/stdin
}

applyTopicsToTags () {
    # applyTopicsToTags:
    # TODO: While this uses action's tags to match against instead of the rules, it doesn't report the
    #       alias which is resulting in the match. Needs more looking into
    # jq --argjson aliases "$TOPICS" '[foreach ($aliases | to_entries[]) as $alias (.; if any($alias.value[] == .) then . + [$alias.key] else . end)] | last' --< /dev/stdin
    jq --argjson topics "$TOPICS" \
'[foreach ($topics | to_entries | reverse[]) as $topic (.; 
    if index($topic.key) then
        . + $topic.value
    else
        .
    end
)] | last' < /dev/stdin
    return $?
}

deployRoomShutdown () {
    # deployRoomShutdown: room_id action
    [ -n "$DRY_RUN" ] && return 0
    local room_id
    local status
    local payload
    local reason
    room_id="$(jq '@uri' -Rr <<< "$1")" || return 1
    # FIXME: No proper error handling if an error thrown here.
    status="$(curl -sf -H "Authorization: Bearer $ACCESS_TOKEN" "$SYNAPSE_BASE_URL/admin/v1/rooms/$room_id/block")" || return 1
    #status='{"block": false}'
    
    if ! jq -e '.block' 1>/dev/null <<< "$status"; then
        payload='{"block": true}'

        # TODO: Add flag for .purge?

        if ! jq -e '.room.silent' 1>/dev/null <<< "$2"; then
            payload="$(jq --argjson pl "$payload" --arg user_id "$USER_ID" '$pl * { new_room_user_id: $user_id }' -nc)"
        fi

        reason="$(jq '.room.reason' -r <<< "$2")"
        if jq -e '.room.reason' 1>/dev/null <<< "$2"; then
            payload="$(jq --argjson pl "$payload" --arg reason "$reason" '$pl * { reason: $reason }' -nc)"
        fi

        #echo "$payload" 1>&2

        curl -sf -X DELETE -d "$payload" \
          -H 'Content-Type: application/json' \
          -H "Authorization: Bearer $ACCESS_TOKEN" "$SYNAPSE_BASE_URL/admin/v1/rooms/$room_id/block"
        return $?
    fi
}

deployRoomDelist () {
    # deployRoomDelist: room_id action
    [ -n "$DRY_RUN" ] && return 0
    local room_id
    room_id="$(jq '@uri' -Rr <<< "$1")" || return 1
    # FIXME: No error handling if an error thrown here.
    # TODO: Check if synapse ACTUALLY lets you do this. Docs say you can but who knows travis probably wrote them
    curl -sf -X PUT -d '{"visibility":"private"}' \
      -H "Content-Type: application/json" \
      -H "Authorization: Bearer $ACCESS_TOKEN" "$BASE_URL/client/r0/directory/list/room/$room_id"
    return $?
}

deployRoomQuarantine () {
    # deployRoomQuarantine: room_id action
    [ -n "$DRY_RUN" ] && return 0
    local room_id
    room_id="$(jq '@uri' -Rr <<< "$1")" || return 1
    # FIXME: No error handling if an error thrown here.
    curl -sf -X POST -d '{}' -H "Authorization: Bearer $ACCESS_TOKEN" "$SYNAPSE_BASE_URL/admin/v1/room/$room_id/media/quarantine"
    return $?
}

deployRoomRule () {
    # deployRoomRule: room_id action
    local action_taken
    local code

    # TODO: Does synapse delist if shutting down? If so we should just skip delist if shutdown is defined
    if jq -e '.room.delist' 1>/dev/null <<< "$2"; then
        action_taken='1'
        deployRoomDelist "$1" "$2"
        # TODO: Failure shouldn't block quarantine or shutdown, not the best way of handling.
        #code="$?"
        #[ "$code" -ne 0 ] && return $code
    fi

    if jq -e '.room.quarantine' 1>/dev/null <<< "$2"; then
        action_taken='1'
        deployRoomQuarantine "$1" "$2"
        code="$?"
        [ "$code" -ne 0 ] && return $code
    fi

    if jq -e '.room.shutdown' 1>/dev/null <<< "$2"; then
        action_taken='1'
        deployRoomShutdown "$1" "$2"
        code="$?"
        [ "$code" -ne 0 ] && return $code
    fi

    [ -z "$action_taken" ] && echo "deployRoomRule: Action defines no action. Odd" 2>&1
    return 0
}

deployUserRule () {
    # deployUserRule: user_id action
    echo "deployUserRule: Not Implemented!" 1>&2
    return 255
}

deployRule () {
    # deployRule: rule action
    local type
    type="$(jq .type -r <<< "$1")"
    if [ "$type" == "m.user" ]; then
        deployUserRule "$1" "$2"
        return $?
    elif [ "$type" == "m.room" ]; then
        deployRoomRule "$1" "$2"
        return $?
    else
        die "deployRule: Internal logic error. Schema check let something slip through!"
    fi
}

ingestRule () {
    # ingestRule: rule index state_key
    local rule_tags
    local actions_index
    local action
    local action_tags
    local match
    local code

    rule_tags="$(oneOfTagsAsArray <<< "$1")" || return 1

    for actions_index in $(arrayIndexList "$ACTIONS"); do
        action="$(jq ".[$((actions_index-1))]" -rc <<< "$ACTIONS")" || return 2
        action_tags="$(oneOfTagsAsArray <<< "$action" | applyTopicsToTags)" || return 3
        match="$(arrayAndIncludes "$rule_tags" "$action_tags")"
        if [ -n "$match" ]; then
            echo "ingestRule[$3:$2]: Found matching tag \"$match\"."
            deployRule "$1" "$action"
            code="$?"
            [ "$code" -ne 0 ] && echo "ingestRule[$3:$2]: Unexpected exit code of $code when handling action." 1>&2
            return $code
        fi
    done
}

ingestPolicy () {
    # ingestPolicy: state state_key
    local rule
    local retcode="0"
    local rules
    rules="$(jq .content.rules -c <<< "$1")"
    for policy_index in $(arrayIndexList "$rules"); do
        rule="$(jq ".[$((policy_index-1))]" -rc <<< "$rules")" || return 1
        ingestRule "$rule" "$policy_index" "$2"
        local code="$?"
        if [ "$code" != "0" ]; then
            echo "ingestPolicy[$policy_index]: Unexpected exit code of $code when handling rule."
            local retcode="2"
        fi
    done
    return $retcode
}

ingestState () {
    # ingestState: state
    local state_key
    state_key="$(stripCtrlChars <<< "$(jq .state_key -r <<< "$1")")"
    if ! checkPolicyIgnored "$1"; then
        if checkPolicyAgainstSchema "$1"; then
            if checkSignature "$1"; then
                ingestPolicy "$1" "$state_key" && genIgnorefileLine "$1" >> "$IGNORED_FILE"
            else
                echo "ingestState[$state_key]: Unexpected GnuPG exit code $?." 1>&2
            fi
        else
            echo "ingestState[$state_key]: Unexpected yajsv exit code $?. This policy is improperly formatted!" 1>&2
            genIgnorefileLine "$1" >> "$IGNORED_FILE"
        fi
    else
        echo "ingestState[$state_key]: Ignored."
    fi
}

ingestPolicyRoom () {
    # ingestPolicyRoom: room_id
    local policies
    local state
    policies="$(fetchRoomPolicies "$1")" || return 1
    for policies_index in $(arrayIndexList "$policies"); do
        state="$(jq ".[$((policies_index-1))]" -rc <<< "$policies")" || return 2
        ingestState "$state" || echo "ingestPolicyRoom[$1]: Unexpected exit code of $? when processing state." 1>&2
    done
}

init () {
    local room_id
    local policy_rooms_index

    for policy_rooms_index in $(arrayIndexList "$(jq '.policy_rooms' -c <<< "$CONFIG")"); do
        room_id="$(jq ".policy_rooms[$((policy_rooms_index-1))]" -r <<< "$CONFIG")" || return 1
        echo "main: Requesting policies for $room_id"
        ingestPolicyRoom "$room_id" || die "init[$room_id]: Unexpected exit code when processing policy room. $?"

        # processPolicyRoom "$room_id"
        #code="$?"
        #if [ "$code" != "0" ]; then echo "main: Unexpected exit code when processing policy room \"$room_id\": $code" 1>&2; fi
    done
}

init