#!/bin/bash
# MKit - simple install helper
# See LICENSE file for copyright and license details.

mkit_import ini
mkit_import util

plugin__lspaths() {
    #
    # List existing paths from $MKIT_PLUGINPATH
    #
    local path
    debug_var MKIT_PLUGINPATH
    tr ':' '\n' <<<"$MKIT_PLUGINPATH" \
      | while read -r path; do
            debug_var path
            test -d "$path" || continue
            echo "$path"
        done
}

plugin__ls() {
    plugin__lspaths \
      | while read -r path; do
            debug_var path
            find "$path" -mindepth 1 -maxdepth 1 -printf '%P\n'
        done
}

plugin__option_bool() {
    #
    # Safely load boolean option $1
    #
    local name=$1
    __plugin__option_safeload \
        "$name" \
        "util__isa_bool" \
        "not a boolean (true|false)"
}

plugin__option_enum() {
    #
    # Safely load enum option $1, allowing values $2..
    #
    __plugin__check_call || return 5
    local name=$1; shift
    local allowed_values=("$@")
    local value
    local desc_allowed
    value=$(plugin__option_single "$name")
    debug_var name value
    test -n "$value" || return 1
    util__isa_enum "$value" "${allowed_values[@]}" || {
        desc_allowed=$(util__join "|" "${allowed_values[@]}")
        warn "not one of supported values ($desc_allowed): $name = $value"
        return 3
    }
    echo "$value"
}

plugin__option_multi() {
    #
    # Print multi-line plugin option $1
    #
    __plugin__check_call || return 5
    local name=$1
    ini values "options:$_MKIT__PLUGIN__NAME:$name" \
      | util__gate_printable
}

plugin__option_single() {
    #
    # Print single-line plugin option $1
    #
    __plugin__check_call || return 5
    local name=$1
    ini 1value "options:$_MKIT__PLUGIN__NAME:$name" \
      | grep .
}

plugin__option_int() {
    #
    # Safely load boolean option $1
    #
    local name=$1
    __plugin__option_safeload \
        "$name" \
        "util__isa_int" \
        "not an integer"
}

plugin__option_name() {
    #
    # Safely load boolean option $1
    #
    local name=$1
    __plugin__option_safeload \
        "$name" \
        "util__isa_name" \
        "not a valid name (alphanumeric, starting with letter)"
}

plugin__option_posint() {
    #
    # Safely load boolean option $1
    #
    local name=$1
    __plugin__option_safeload \
        "$name" \
        "util__isa_posint" \
        "not a positive integer"
}

plugin__path() {
    #
    # Print path to plugin file $1
    #
    local name=$1
    local binpath
    plugin__lspaths \
      | while read -r path; do
            binpath="$path/$name"
            debug_var binpath
            test -x "$binpath" || continue
            echo "$binpath"
        done
}

plugin__handle() {
    #
    # Run method $2 of plugin $1
    #
    local _MKIT__PLUGIN__NAME=$1
    local method=$2
    local require=true
    local path
    local fn
    test "${method:0:1}" == "." && {
        require=false
        method=${method:1}
    }
    fn=${_MKIT__PLUGIN__NAME}__${method}
    path=$(plugin__path "$_MKIT__PLUGIN__NAME")
    test -n "$path" || die "plugin not found: $_MKIT__PLUGIN__NAME"
    bash -n "$path" || die "syntax errors in plugin file: $path"
    #shellcheck disable=SC1090
    . "$path" || die "error importing plugin: $_MKIT__PLUGIN__NAME at $path"
    type -t "$fn" | grep -qw function || {
        $require && die "missing handler: $fn() in plugin $_MKIT__PLUGIN__NAME at $path"
        debug "SILENTLY SKIPPING UNDEFINED HANDLER: $fn() in $_MKIT__PLUGIN__NAME at $path"
        return 0
    }
    debug "RUNNING HANDLER"
    debug_var fn
    "$fn"
}

plugin__isvalid() {
    #
    # True if plugin $1 is valid
    #
    local plugin=$1
    plugin__ls | grep -qwxe "$plugin"
}

__plugin__check_call() {
    #
    # Check that this call is valid
    #
    local func=${FUNCNAME[1]}
    local caller=${FUNCNAME[2]}
    test -n "$_MKIT__PLUGIN__NAME" && return 0
    warn "illegal call: $func() from $caller() _MKIT__PLUGIN__NAME=$_MKIT__PLUGIN__NAME" \
         "  hint: are we inside plugin?"
    return 3
}

__plugin__option_safeload() {
    #
    # Safely load option $1 with validator $2 and error message $3
    #
    __plugin__check_call || return 5
    local name=$1
    local validator=$2
    local msg=$3
    local value
    value=$(plugin__option_single "$name")
    debug_var name value
    test -n "$value" || return 1
    "$validator" "$value" || {
        warn "$msg: $name=$value"
        return 3
    }
    echo "$value"
}