#!/bin/bash
# ods-usage - calculate On-Demand Sandbox credits used from a getRealmUsage response
#
# Usage:
#   ods-usage [api_response]
#   ods-usage -h
#
# Options:
#   api_response   JSON response from getRealmUsage (ODS API); if omitted,
#                  the script pulls JSON from the clipboard via pbpaste
#   -h, --help     Show help message
#
# Example Output:
#   Sandbox Counts
#   created: 9
#   active:  8
#   deleted: 0
#   Uptime & Downtime
#   min up:   1389
#   > medium: 1389
#   min down: 194006
#   Credits Used
#   up:    1389
#   down:  58201
#   total: 59590
#
# References:
#   https://admin.dx.commercecloud.salesforce.com/#/Realms/getRealmUsage
#   https://admin.dx.commercecloud.salesforce.com/api/v1/realms/xxxx/usage?from=2020-01-01&to=2020-02-01&detailedReport=false

_ods_usage() (
    local SCRIPT_NAME; SCRIPT_NAME="$(basename "${BASH_SOURCE[0]}")"
    case "${BASH_SOURCE[0]}" in /dev/*|/proc/*) SCRIPT_NAME="" ;; esac
    case "$SCRIPT_NAME" in ""|bash|sh|zsh|dash) SCRIPT_NAME="ods-usage" ;; esac

    _error() { echo "[ERR][$SCRIPT_NAME] $*" >&2; }

    _terminal_cols() {
        # Returns terminal column count (integer), falling back to 80
        # Prefers stty against /dev/tty (real ioctl-sourced width), then $COLUMNS
        # Avoids tput to drop the runtime dependency
        # The { ...; } 2>/dev/null wrapping silences the shell's own redirect
        # error ("/dev/tty: Device not configured") when /dev/tty is unavailable
        local cols=""
        local out=""
        if out="$({ stty size </dev/tty; } 2>/dev/null)"; then
            cols="${out##* }"
            case "$cols" in
                ''|*[!0-9]*) cols="" ;;
            esac
            [ "$cols" ] && [ "$cols" -gt 0 ] 2>/dev/null && { printf '%s\n' "$cols"; return 0; }
        fi
        cols="${COLUMNS:-}"
        case "$cols" in
            ''|*[!0-9]*) cols="" ;;
        esac
        [ "$cols" ] && [ "$cols" -gt 0 ] 2>/dev/null && { printf '%s\n' "$cols"; return 0; }
        printf '80\n'
    }

    _show_help() {
        local s; [ -t 1 ] && s=$'\033[4m'
        local r; [ -t 1 ] && r=$'\033[24m'
        echo "NAME"
        echo "  $SCRIPT_NAME - calculate On-Demand Sandbox credits used from an ODS API response"
        echo "SYNOPSIS"
        echo "  $SCRIPT_NAME [${s}api_response${r}]"
        echo "  $SCRIPT_NAME -h"
        echo "DESCRIPTION"
        echo "  Parses a getRealmUsage JSON response from the Salesforce B2C Commerce"
        echo "  On-Demand Sandbox (ODS) API and summarizes sandbox counts, uptime/"
        echo "  downtime by profile, and credits used. Credit multipliers:"
        echo "    medium=1, large=2, xlarge=4 (per minute up)"
        echo "    stopped=0.3 (per minute down, all profiles)"
        echo ""
        echo "  Primary workflow: copy the JSON response from the ODS API Swagger UI"
        echo "  (https://admin.dx.commercecloud.salesforce.com/#/Realms/getRealmUsage),"
        echo "  then run \`$SCRIPT_NAME\` with no arguments -- it will read JSON from"
        echo "  the clipboard via pbpaste. You can also pass the JSON as an argument."
        echo "INPUT"
        echo "  Expects JSON with these required fields under .data:"
        echo "    createdSandboxes, activeSandboxes, deletedSandboxes,"
        echo "    minutesUp, minutesDown, minutesUpByProfile[]"
        echo "OPTIONS"
        echo "  ${s}api_response${r}   JSON response (if omitted, read from clipboard via pbpaste)"
        echo "  -h, --help     Show this help message"
        echo "DEPENDENCIES"
        echo "  jq, pbpaste (macOS clipboard; required for clipboard mode)"
        echo "EXAMPLES"
        echo "  $SCRIPT_NAME '{\"data\":{\"createdSandboxes\":9,...}}'"
        echo "  $SCRIPT_NAME                 # reads JSON from clipboard (macOS)"
        echo "  pbpaste | xargs -0 $SCRIPT_NAME   # explicit clipboard pipe"
        echo "EXIT STATUS"
        echo "  0  Success"
        echo "  2  Usage error (invalid JSON, missing required fields, no input)"
        echo "  3  Dependency error (jq missing; pbpaste missing in clipboard mode)"
    }

    case "$1" in
        -h|--help) _show_help; return 0 ;;
    esac

    if ! command -v jq >/dev/null 2>&1; then
        _error "jq is required"
        return 3
    fi

    # Define one of two versions of a jq helper function, to pipe the input JSON and specify raw output each time
    # Helper will use input if arguments are provided, otherwise it will pull from the clipboard
    if [ $# -gt 0 ]; then
        local json="$*"
        # Define jq helper if input is valid JSON, otherwise exit with error status
        if echo "$json" | jq empty 2>/dev/null; then
            _jq() { echo "$json" | jq -r "$@"; }
        else
            _error "Input is not valid JSON (first line preview below). Run \`$SCRIPT_NAME -h\` for usage"
            local width; width="$(_terminal_cols)"
            echo "$*" | head -n 1 | cut -c "1-$width" >&2
            return 2
        fi
    else
        if ! command -v pbpaste >/dev/null 2>&1; then
            _error "pbpaste is required for clipboard mode (macOS only). Pass JSON as an argument instead"
            return 3
        fi
        # Define jq helper if clipboard contains valid JSON, otherwise exit with error status
        if pbpaste | jq empty 2>/dev/null; then
            _jq() { pbpaste | jq -r "$@"; }
        else
            _error "No arguments provided and clipboard does not contain valid JSON. Run \`$SCRIPT_NAME -h\` for usage"
            return 2
        fi
    fi

    # Validate required fields exist before processing -- missing fields would
    # otherwise print "null" and leak jq errors to stderr while exiting 0
    local check; check="$(_jq '.data | has("createdSandboxes") and has("activeSandboxes") and has("deletedSandboxes") and has("minutesUp") and has("minutesDown")')"
    if [ "$check" != "true" ]; then
        _error "Input JSON is missing required fields (expected .data.createdSandboxes, .data.activeSandboxes, .data.deletedSandboxes, .data.minutesUp, .data.minutesDown). Run \`$SCRIPT_NAME -h\` for usage"
        return 2
    fi

    # If output is being piped or redirected, do not print control characters for text formatting
    local smul=''
    local rmul=''
    if [ -t 1 ]; then # stdout (fd1) is a terminal
        smul=$'\033[4m'  # start underline
        rmul=$'\033[24m' # remove underline
    fi

    # Define credit cost per minute for each ODS resource profile (all profiles are 0.3 credits per minute down)
    local credit_multi_medium=1
    local credit_multi_large=2
    local credit_multi_xlarge=4
    local credit_multi_stopped="3 / 10" # injected into $(()) later, because $((3 / 10)) == 0

    # Print the number of sandboxes created, active, and deleted during the timeframe
    echo "${smul}Sandbox Counts${rmul}"
    local sbx_count_created; sbx_count_created="$(_jq '.data.createdSandboxes')"
    local sbx_count_active;   sbx_count_active="$(_jq '.data.activeSandboxes')"
    local sbx_count_deleted; sbx_count_deleted="$(_jq '.data.deletedSandboxes')"
    echo "created: $sbx_count_created"
    echo "active:  $sbx_count_active"
    echo "deleted: $sbx_count_deleted"

    # Print minutes up and down (per resource profile for uptime only, as it does not apply to downtime)
    echo "${smul}Uptime & Downtime${rmul}"
    local min_down; min_down="$(_jq '.data.minutesDown')"
    local min_up;     min_up="$(_jq '.data.minutesUp')"
    local min_up_medium; min_up_medium="$(_jq '.data.minutesUpByProfile[] | select(.profile=="medium") | .minutes')"
    local min_up_large;   min_up_large="$(_jq '.data.minutesUpByProfile[] | select(.profile=="large")  | .minutes')"
    local min_up_xlarge; min_up_xlarge="$(_jq '.data.minutesUpByProfile[] | select(.profile=="xlarge") | .minutes')"
    echo "min up:   $min_up"
    [ "$min_up_medium" ] && echo "> medium: $min_up_medium"
    [ "$min_up_large" ]  && echo ">  large: $min_up_large"
    [ "$min_up_xlarge" ] && echo "> xlarge: $min_up_xlarge"
    echo "min down: $min_down"

    # Print credits used by uptime, downtime, and in total
    echo "${smul}Credits Used${rmul}"
    local credits_used_up=$((min_up_medium*credit_multi_medium + min_up_large*credit_multi_large + min_up_xlarge*credit_multi_xlarge))
    local credits_used_down; credits_used_down="$(eval 'echo $((min_down * '"$credit_multi_stopped"'))')"
    local credits_used_total=$((credits_used_up + credits_used_down))
    echo "up:    $credits_used_up"
    echo "down:  $credits_used_down"
    echo "total: $credits_used_total"
)

_ods_usage "$@"
__ods_usage_rc=$?
unset -f _ods_usage
if [ -n "${BASH_SOURCE[0]}" ] && [ "${BASH_SOURCE[0]}" != "$0" ]; then
    eval "unset __ods_usage_rc; return $__ods_usage_rc"
fi
eval "unset __ods_usage_rc; exit $__ods_usage_rc"