#----------------------------------*-sh-*--------------------------------------
# =========                 |
# \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
#  \\    /   O peration     |
#   \\  /    A nd           | www.openfoam.com
#    \\/     M anipulation  |
#------------------------------------------------------------------------------
#     Copyright (C) 2018-2020 OpenCFD Ltd.
#------------------------------------------------------------------------------
# License
#     This file is part of OpenFOAM, distributed under GPL-3.0-or-later.
#
# Script
#     paraviewFunctions
#
# Description
#     Helper functions for CMake with ParaView.
#     Setup of variables for creating ParaView plugins
#
# Requires
#     ParaView_DIR   (unless system)
#     PV_PLUGIN_PATH (or rely on automatic mechanism)
#
# Provides Functions
#     get_pvplugin_api, have_pvplugin_support, no_paraview, echo_paraview
#     cmakeVtk, cmakePv, cmakePvInstall
#
# Variables on success
#     HAVE_PVPLUGIN_SUPPORT
#     FOAM_PV_PLUGIN_LIBBIN
#     PARAVIEW_API - the paraview major/minor numbers (eg 5.6)
#     PARAVIEW_INC_DIR
#
# Note
#     The OpenFOAM plugin must be the first in PV_PLUGIN_PATH and have
#     paraview-major.minor encoded in its name.
#
#------------------------------------------------------------------------------
. ${WM_PROJECT_DIR:?}/wmake/scripts/sysFunctions    # General system functions
. ${WM_PROJECT_DIR:?}/wmake/scripts/cmakeFunctions  # Require cmake functions

#------------------------------------------------------------------------------

# Reset variables
no_paraview()
{
    unset HAVE_PVPLUGIN_SUPPORT FOAM_PV_PLUGIN_LIBBIN
    unset PARAVIEW_API PARAVIEW_INC_DIR
}


# Report
echo_paraview()
{
    echo "paraview=${HAVE_PVPLUGIN_SUPPORT:-false}"
    echo "root=\"$ParaView_DIR\""
    echo "include=\"$PARAVIEW_INC_DIR\""
    echo "plugin=\"$FOAM_PV_PLUGIN_LIBBIN\""
    echo "api=$PARAVIEW_API"
}


# CMake into objectsDir with VTK_DIR dependency
# 1 - sourceDir
# 2.. optional cmake defines
cmakeVtk()
{
    cmakeVersioned "VTK_DIR=$VTK_DIR" "$@"
}


# CMake into objectsDir with ParaView_DIR dependency
# 1 - sourceDir
# 2.. optional cmake defines
cmakePv()
{
    cmakeVersioned "ParaView_DIR=$ParaView_DIR" "$@"
}

# CMake into objectsDir with ParaView_DIR dependency
# 1 - sourceDir
# 2.. optional cmake defines
cmakePvInstall()
{
    cmakeVersionedInstall "ParaView_DIR=$ParaView_DIR" "$@"
}


# Build library - use sentinel file(s) to handle paraview version changes
# Some difficulty handling different installation options as well
# as wmake options, so only handle build/configure information for now
#
# 1 - libName
# 2... build/configure information
#
# Similar to wmakeVersioned
wmakeLibPv()
{
    local depend="ParaView_DIR=$ParaView_DIR"
    local libName="$1"
    shift 1
    local sentinel

    sentinel=$(sameDependency "$libName" "$depend" $@) || \
        wclean "$libName"

    wmake $targetType "$libName" \
    && storeDependency "$sentinel" "$depend" $@
}

# Get ParaView API from given path.
# Eg, "/path/paraview-dir/paraview-5.6" -> "5.6"
#
# Or the output from `paraview --version`
# Eg, "paraview version 5.6.3" -> "5.6"
#
# 1 - the input path ending with paraview-x.y, or paraview --version information
#
# On success, return 0 and echo value
#
get_pvapi()
{
    local pv_api

    # Extract paraview major+minor version from the directory name
    # From /path/paraview-5.6 -> 5.6
    pv_api=$(echo "${1:-none}" | \
        sed -ne 's@^.*/@@;s@^[^0-9]*\([0-9][0-9]*\.[0-9][0-9]*\).*$@\1@p')

    if [ -z "$pv_api" ]
    then
        # Extract paraview major+minor version from "paraview --version" information
        pv_api=$(echo "${1:-none}" | \
            sed -ne 's@^.*version *\([0-9][0-9]*\.[0-9][0-9]*\).*$@\1@p')
    fi

    [ -n "$pv_api" ] || return 1

    # OK
    echo "$pv_api"
}


# Extract ParaView plugin api number from PV_PLUGIN_PATH
# On success, return 0 and export variables
# -> FOAM_PV_PLUGIN_LIBBIN, PARAVIEW_API
#
get_pvplugin_api()
{
    # OK
    unset FOAM_PV_PLUGIN_LIBBIN  PARAVIEW_API
    local pv_api targetDir

    # The OpenFOAM plugin must be the first in PV_PLUGIN_PATH
    # and must have the paraview major+minor version encoded in its name!
    # Eg, PV_PLUGIN_PATH="$FOAM_LIBBIN/paraview-5.5"

    # Get the first entry from PV_PLUGIN_PATH=dir1;dir2;...
    targetDir="${PV_PLUGIN_PATH##;}"
    targetDir="${targetDir%%;*}"

    # Extract paraview major+minor version from directory name
    # From /path/paraview-5.6 -> 5.6
    pv_api=$(get_pvapi "$targetDir")

    [ -n "$pv_api" ] || return 1

    # OK
    export FOAM_PV_PLUGIN_LIBBIN="$targetDir"
    export PARAVIEW_API="$pv_api"

    return 0 # success
}


# Test if a ParaView plugin can be built.
# On success, return 0 and export variables
# -> HAVE_PVPLUGIN_SUPPORT, FOAM_PV_PLUGIN_LIBBIN,
#    PARAVIEW_API, PARAVIEW_INC_DIR
#
# There are several prerequisites for building plugins
#
have_pvplugin_support()
{
    local warn="==> skip paraview-plugin"
    local settings pv_api pv_executable installDir binDir includeDir targetDir

    # Trivial check
    command -v cmake >/dev/null || {
        echo "$warn (no cmake)"
        return 1
    }

    if get_pvplugin_api
    then
        targetDir="$FOAM_PV_PLUGIN_LIBBIN"
        pv_api="$PARAVIEW_API"
    fi
    unset FOAM_PV_PLUGIN_LIBBIN PARAVIEW_API

    # Probably not needed...
    # if [ -z "$targetDir" ] || [ -z "$pv_api" ]
    # then
    #     echo "$warn (could not determine target or major.minor version)"
    #     echo "    PV_PLUGIN_PATH=${PV_PLUGIN_PATH:-???}"
    #     return 1
    # fi

    # Include/library names
    local header="pqServerManagerModel.h"

    if [ -n "$ParaView_DIR" ]
    then
        # ParaView_DIR defined. Look for include/

        # Unless already known, get API value from include directory name
        if [ -z "$pv_api" ]
        then
            for settings in $(find "$ParaView_DIR"/include -maxdepth 1 -name 'paraview-*' -type d)
            do
                pv_api=$(get_pvapi "$settings") && break
            done

            if [ -z "$pv_api" ]
            then
                echo "$warn (could not determine paraview major.minor version)"
                return 1
            fi
        fi

        header=$(findFirstFile \
            "$ParaView_DIR/include/paraview-$pv_api/$header" \
            "$ParaView_DIR/include/paraview/$header"
        )

    else
        # No ParaView_DIR defined
        # - use location of 'paraview' to guess an equivalent ParaView_DIR
        # - assume paraview-config works, but might be removed too!

        pv_executable="$(command -v paraview 2>/dev/null)" || {
            echo "$warn (no paraview found?)"
            return 2
        }
        binDir="${pv_executable%/*}"  # Eg, /usr/bin/paraview -> /usr/bin
        installDir="${binDir%/*}"     # Eg, /usr/bin -> /usr

        case "$installDir" in
        (/*)    # An absolute path
            includeDir="$installDir/include"  # Eg, /usr -> /usr/include
        ;;
        esac

        # Unless already known, get API value from `paraview --version` information
        if [ -z "$pv_api" ]
        then
            pv_api=$(get_pvapi "$("$pv_executable" --version)")
            if [ -z "$pv_api" ]
            then
                echo "$warn (could not determine paraview major.minor version)"
                return 1
            fi
        fi

        header=$(findFirstFile \
            "$(paraview-config --include 2>/dev/null |sed -ne 's/^ *-I//p')/$header"\
            "${includeDir:+$includeDir/paraview-$pv_api/$header}" \
            "${includeDir:+$includeDir/paraview/$header}" \
            /usr/local/include/"paraview-$pv_api/$header" \
            /usr/local/include/paraview/"$header" \
            /usr/include/"paraview-$pv_api/$header" \
            /usr/include/paraview/"$header" \
            )
    fi

    # ----------------------------------

    # Header
    [ -n "$header" ] || {
        [ -n "$warn" ] && echo "$warn (no header)"
        return 2
    }

    # ----------------------------------

    # OK
    # Use FOAM_LIBBIN/paraview-maj.min as default
    export HAVE_PVPLUGIN_SUPPORT=true
    export FOAM_PV_PLUGIN_LIBBIN="${targetDir:-$FOAM_LIBBIN/paraview-$pv_api}"
    export PARAVIEW_API="$pv_api"
    export PARAVIEW_INC_DIR="${header%/*}"      # Basename

    return 0 # success
}


# Force reset of old variables
no_paraview

# Test/query
case "$1" in
-test)
    have_pvplugin_support
    echo_paraview
    ;;
-query)
    ## query_paraview
    ;;
esac

#------------------------------------------------------------------------------