#!/bin/bash
# SPDX-license-identifier: Apache-2.0
##############################################################################
# Copyright (c) 2016 NEC and others.
# All rights reserved. This program and the accompanying materials
# are made available under the terms of the Apache License, Version 2.0
# which accompanies this distribution, and is available at
# http://www.apache.org/licenses/LICENSE-2.0
##############################################################################

set +e

DOCS_DIR=${DOCS_DIR:-docs}
INDEX_RST=${INDEX_RST:-index.rst}
BUILD_DIR=${BUILD_DIR:-docs_build}
OUTPUT_DIR=${OUTPUT_DIR:-docs_output}
SRC_DIR=${SRC_DIR:-$BUILD_DIR/_src}
VENV_DIR=${VENV_DIR:-$BUILD_DIR/_venv}
OPNFVDOCS_DIR=${OPNFVDOCS_DIR:-$BUILD_DIR/_opnfvdocs}
GERRIT_COMMENT=${GERRIT_COMMENT:-}

revision="$(git rev-parse --short HEAD)"
rev_full="$(git rev-parse HEAD)"
version="$(git describe --abbrev=0 2> /dev/null || echo draft) ($revision)"
project="$(basename $(git rev-parse --show-toplevel))"
html_notes="    Revision: $rev_full\n    Build date: $(date -u +'%Y-%m-%d')"
opnfv_logo="$OPNFVDOCS_DIR/etc/opnfv-logo.png"
copyright="$(date +%Y), OPNFV."
copyrightlong="$(date +%Y), OPNFV. Licensed under CC BY 4.0."
error_count=0

function set_error() {
    # TODO(yujunz) log detail errors
    error_count=$((error_count + 1))
}

if [ "$(uname)" == "Darwin" ]; then
  # Override system $SED/$FIND with gnu $SED and gnu $FIND
  # If not found, install with
  # $ brew install gnu-sed findutils
  echo "macOS detected."
  SED="gsed"
  FIND="gfind"
else
  SED="sed"
  FIND="find"
fi

function check_rst_doc() {
    _src="$1"

    # Note: This check may fail in many jobs for building project docs, since
    #       the old sample has lines more than 120. We ignore failures on this
    #       check right now, but these have to be fixed before OPNFV B release.
    _out=$(doc8 --max-line-length 240 --ignore D000 "$_src") || {
        _msg='Warning: rst validation (doc8) has failed, please fix the following error(s).'
        _errs=$(echo "$_out" | $SED -n -e "/^$_src/s/^/    /p")
        echo
        echo -e "$_msg\n$_errs"
        echo
        if [ -n "$GERRIT_COMMENT" ]; then
            echo -e "$_msg\n$_errs" >> "$GERRIT_COMMENT"
        fi
    }
}

function add_html_notes() {
    _src="$1"

    $FIND "$_src" -name '*.rst' | while read file
    do
        if grep -q -e ' _sha1_' "$file" ; then
            # TODO: remove this, once old templates were removed from all repos.
            echo
            echo "Warn: '_sha1_' was found in [$file], use the latest document template."
            echo "      See http://artifacts.opnfv.org/opnfvdocs/docs/how-to-use-docs ."
            echo
            $SED -i "s/ _sha1_/ $git_sha1/g" "$file"
        fi
        $SED -i -e "\$a\\\n..\n$html_notes" "$file"
    done
}

function prepare_src_files() {
    mkdir -p "$(dirname $SRC_DIR)"

    if [ -e "$SRC_DIR" ]; then
        rm -rf "$SRC_DIR"
    fi
    cp -r "$DOCS_DIR" "$SRC_DIR"
    add_html_notes "$SRC_DIR"
}

function add_config() {
    _conf="$1"
    _param="$2"
    _val="$3"

    if ! grep -q -e "^$_param = " "$_conf" ; then
        echo "Adding '$_param' into $_conf ..."
        echo "$_param = $_val" >> "$_conf"
    fi
}

# Note: User can customize config for specific document by creating 'conf.py'
#       in the taeget document dir (e.g. docs/abc/conf.py). This config file does
#       not need to cover all config parameter, as all missing parameter will be
#       automatically filled by this function.
function prepare_config() {
    _src="$1"
    _name="$2"
    _conf="$_src/conf.py"

    touch "$_conf"

    # default params
    # Note: If you want to add a new sphinx extention here, you may need python
    #       package for it (e.g. python package 'sphinxcontrib-httpdomain' is
    #       required by 'sphinxcontrib.httpdomain'). If you need such python
    #       package, add the name of the python package into the requirement
    #       list 'docs/etc/requirements.txt' .
    add_config "$_conf" 'extensions' \
    "['sphinxcontrib.httpdomain', 'sphinx.ext.autodoc', 'sphinx.ext.viewcode', 'sphinx.ext.napoleon']"
    add_config "$_conf" 'needs_sphinx' "'1.3'"
    add_config "$_conf" 'numfig' "True"
    add_config "$_conf" 'master_doc' "'index'"
    add_config "$_conf" 'pygments_style' "'sphinx'"
    add_config "$_conf" 'html_use_index' "False"
    add_config "$_conf" 'html_last_updated_fmt' "'%b %d, %Y'"
    add_config "$_conf" 'html_logo' "'opnfv-logo.png'"
    add_config "$_conf" 'html_sidebars' \
                        "{'**': ['globaltoc.html',
                                 '$(cd $OPNFVDOCS_DIR; pwd)/etc/pagemenu.html',
                                 'searchbox.html']}"

    # genarated params
    add_config "$_conf" 'release' "u'$version'"
    add_config "$_conf" 'version' "u'$version'"
    add_config "$_conf" 'project' "u'$project'"
    add_config "$_conf" 'copyright' "u'$copyrightlong'"
    add_config "$_conf" 'rst_epilog' "u'$html_notes'"

    echo "sphinx config to be used:"
    echo
    $SED -e "s/^/    /" "$_conf"
    echo
}

function is_top_dir() {
    [[ "$1" == "$DOCS_DIR" ]]
}

function generate_name_for_top_dir() {
    for suffix in '' '.top' '.all' '.master' '_' '__' '___'
    do
        _name="$(basename $DOCS_DIR)$suffix"
        [[ -e "$DOCS_DIR/$_name" ]] && continue
        echo "$_name"
        return
    done

    echo "Error: cannot find name for top directory [$DOCS_DIR]"
    set_error
}

function generate_name() {
    _dir=$1

    if is_top_dir "$_dir" ; then
        _name=$(generate_name_for_top_dir $DOCS_DIR)
    else
        _name="${_dir#$DOCS_DIR/}"
    fi
    # Replace '/' by '_'
    echo "${_name////_}"
}


if [[ ! -d "$OPNFVDOCS_DIR" ]] ; then
    echo "Error: $OPNFVDOCS_DIR dir not found."
    echo "See http://artifacts.opnfv.org/opnfvdocs/docs/how-to-use-docs ."
    set_error
fi

if ! which virtualenv > /dev/null ; then
    echo "Error: 'virtualenv' not found. Exec 'sudo pip install virtualenv' first."
    set_error
fi

# workaround for doc8 error in python2.6
if [[ $(python -V 2>&1) == Python\ 2.6.* ]] && [ -e /usr/bin/python2.7 ]; then
    echo "creating venv with Python 2.7 instead of Python 2.6.x ..."
    virtualenv "$VENV_DIR" --python=/usr/bin/python2.7
else
    virtualenv "$VENV_DIR"
fi

source "$VENV_DIR/bin/activate"
pip install -r "$OPNFVDOCS_DIR/etc/requirements.txt"

check_rst_doc $DOCS_DIR

prepare_src_files

if [ -e "$DOCS_DIR/pre-hook.sh" ]; then
    source "$DOCS_DIR/pre-hook.sh"
fi

$FIND $DOCS_DIR -name $INDEX_RST -printf '%h\n' | while read dir
do
    name=$(generate_name $dir)
    if is_top_dir "$dir" ; then
        src="$SRC_DIR"
    else
        src="$SRC_DIR/${dir#$DOCS_DIR/}"
    fi
    build="$BUILD_DIR/$name"
    output="$OUTPUT_DIR/$name"

    echo
    echo "#################${dir//?/#}"
    echo "Building DOCS in $dir"
    echo "#################${dir//?/#}"
    echo

    prepare_config "$src" "$name"
    cp -f $opnfv_logo "$src/opnfv-logo.png"

    mkdir -p "$output"

    {
        sphinx-build -b singlehtml -t singlehtml -E "$src" "$output"
    } || {
        msg="Error: HTML creation for $dir has failed."
        echo
        echo "$msg"
        echo
        if [ -n "$GERRIT_COMMENT" ]; then
            echo "$msg" >> "$GERRIT_COMMENT"
        fi
    }

    if is_top_dir "$dir" ; then
        # NOTE: Having top level document (docs/index.rst) is not recommended.
        #       It may cause conflicts with other docs (mostly with HTML
        #       folders for contents in top level docs and other document
        #       folders). But, let's try merge of those contents into the top
        #       docs directory.
        (
            cd $output
            $FIND . -type d -print | xargs -I d mkdir -p ../d
            $FIND . -type f -print | xargs -I f mv -b f ../f
        )
        rm -rf "$output"
    fi

done

deactivate

exit $error_count