#!/usr/bin/env bash

set -o noclobber -o noglob -o nounset -o pipefail
IFS=$'\n'

## If the option `use_preview_script` is set to `true`,
## then this script will be called and its output will be displayed in ranger.
## ANSI color codes are supported.
## STDIN is disabled, so interactive scripts won't work properly

## This script is considered a configuration file and must be updated manually.
## It will be left untouched if you upgrade ranger.

## Because of some automated testing we do on the script #'s for comments need
## to be doubled up. Code that is commented out, because it's an alternative for
## example, gets only one #.

## Meanings of exit codes:
## code | meaning    | action of ranger
## -----+------------+-------------------------------------------
## 0    | success    | Display stdout as preview
## 1    | no preview | Display no preview at all
## 2    | plain text | Display the plain content of the file
## 3    | fix width  | Don't reload when width changes
## 4    | fix height | Don't reload when height changes
## 5    | fix both   | Don't ever reload
## 6    | image      | Display the image `$IMAGE_CACHE_PATH` points to as an image preview
## 7    | image      | Display the file directly as an image

## Script arguments
FILE_PATH="${1}"         # Full path of the highlighted file
PV_WIDTH="${2}"          # Width of the preview pane (number of fitting characters)
## shellcheck disable=SC2034 # PV_HEIGHT is provided for convenience and unused
PV_HEIGHT="${3}"         # Height of the preview pane (number of fitting characters)
IMAGE_CACHE_PATH="${4}"  # Full path that should be used to cache image preview
PV_IMAGE_ENABLED="${5}"  # 'True' if image previews are enabled, 'False' otherwise.

FILE_EXTENSION="${FILE_PATH##*.}"
FILE_EXTENSION_LOWER="$(printf "%s" "${FILE_EXTENSION}" | tr '[:upper:]' '[:lower:]')"

## Settings
HIGHLIGHT_SIZE_MAX=262143  # 256KiB
HIGHLIGHT_TABWIDTH=${HIGHLIGHT_TABWIDTH:-8}
HIGHLIGHT_STYLE=${HIGHLIGHT_STYLE:-pablo}
HIGHLIGHT_OPTIONS="--replace-tabs=${HIGHLIGHT_TABWIDTH} --style=${HIGHLIGHT_STYLE} ${HIGHLIGHT_OPTIONS:-}"
PYGMENTIZE_STYLE=${PYGMENTIZE_STYLE:-autumn}
OPENSCAD_IMGSIZE=${RNGR_OPENSCAD_IMGSIZE:-1000,1000}
OPENSCAD_COLORSCHEME=${RNGR_OPENSCAD_COLORSCHEME:-Tomorrow Night}

handle_extension() {
    case "${FILE_EXTENSION_LOWER}" in

        ## OpenDocument
        odt|ods|odp|sxw)
            ## Preview as markdown conversion
            pandoc -s -t markdown -- "${FILE_PATH}" && exit 5
            exit 1;;

        ## HTML
        htm|html|xhtml)
            ## Preview as text conversion
            lynx -dump -- "${FILE_PATH}" && exit 5
            exit 1;;

        ## JSON
        json)
            jq --color-output . "${FILE_PATH}" && exit 5
            exit 1;;

    esac
}

handle_image() {
    local DEFAULT_SIZE="1920x1080"

    local mimetype="${1}"
    case "${mimetype}" in

        ## Image
        image/*)
            local orientation
            orientation="$( identify -format '%[EXIF:Orientation]\n' -- "${FILE_PATH}" )"
            if [[ -n "$orientation" && "$orientation" != 1 ]]; then
                convert -- "${FILE_PATH}" -auto-orient "${IMAGE_CACHE_PATH}" && exit 6
            fi
            exit 7;;

        ## Video
        video/*)
            # Thumbnail
            ffmpegthumbnailer -i "${FILE_PATH}" -o "${IMAGE_CACHE_PATH}" -s 0 && exit 6
            exit 1;;

        ## PDF
        application/pdf)
            pdftoppm -f 1 -l 1 \
                     -scale-to-x "${DEFAULT_SIZE%x*}" \
                     -scale-to-y -1 \
                     -singlefile \
                     -jpeg -tiffcompression jpeg \
                     -- "${FILE_PATH}" "${IMAGE_CACHE_PATH%.*}" \
                && exit 6 || exit 1;;

    esac
}

handle_mime() {
    local mimetype="${1}"
    case "${mimetype}" in

        ## Text
        text/* | */xml)
            ## Syntax highlight
            if [[ "$( stat --printf='%s' -- "${FILE_PATH}" )" -gt "${HIGHLIGHT_SIZE_MAX}" ]]; then
                exit 2
            fi
            if [[ "$( tput colors )" -ge 256 ]]; then
                local pygmentize_format='terminal256'
                local highlight_format='xterm256'
            else
                local pygmentize_format='terminal'
                local highlight_format='ansi'
            fi
            env HIGHLIGHT_OPTIONS="${HIGHLIGHT_OPTIONS}" highlight \
                --out-format="${highlight_format}" \
                --force -- "${FILE_PATH}" && exit 5
            env COLORTERM=8bit bat --color=always --style="plain" \
                -- "${FILE_PATH}" && exit 5
            pygmentize -f "${pygmentize_format}" -O "style=${PYGMENTIZE_STYLE}"\
                -- "${FILE_PATH}" && exit 5
            exit 2;;

        ## Media
        image/* | video/* | audio/*)
            exiftool "${FILE_PATH}" && exit 5
            exit 1;;

    esac
}

handle_fallback() {
    echo '----- File Type Classification -----' && file --dereference --brief -- "${FILE_PATH}" && exit 5
    exit 1
}

MIMETYPE="$( file --dereference --brief --mime-type -- "${FILE_PATH}" )"
if [[ "${PV_IMAGE_ENABLED}" == 'True' ]]; then
    handle_image "${MIMETYPE}"
fi
handle_extension
handle_mime "${MIMETYPE}"
handle_fallback

exit 1