#!/bin/bash

requirements_dir="$(realpath "$(dirname $0)/..")"

usage()
{
    echo "
Usage: req.sh list [options...] <type> [id]

    type: req | dml | ass | need
    id: filters items for the given id

    options:

    -S    lists unsatisfied requirements
    -p    lists requirements sourced from [id]
    -P    lists unsourced requirements
"
}

while getopts ":S:P:p" o
do
    case "$o" in
        S)
            unsatisfied=1
            shift 1
            ;;
        P)
            unsourced=1
            shift 1
            ;;
        p)
            sourced=1
            shift 1
            ;;
        *)
            echo "ERROR: ${o} is not a valid option!"
            usage
            exit 1
            ;;
    esac
done

type="$1"
id="$2"

if [ "$type" == "" ]
then
    echo "ERROR: you didn't provide a type!"
    usage
    exit 1
fi

case "$type" in
    req)
        dir="${requirements_dir}/catalogue"
        ;;
    dml)
        dir="${requirements_dir}/data_models"
        ;;
    ass)
        dir="${requirements_dir}/assumptions"
        ;;
    need)
        dir="${requirements_dir}/needs"
        ;;
    *)
        usage
        exit 1
esac

if [ "$sourced" == 1 ]
then
    echo "
${type} items sourced from id ${type}-*${id}
---------------------------------------------------------------------------
"
    filenames=(${dir}/${type}-*.md)
    for filename in "${filenames[@]}"
    do
        is_sourced="$(cat $filename | grep -E "^Sources?:.*\b${type}-[0-9]*${id}\b")"
        if [ -n "$is_sourced" ]
        then
            echo "$(basename "$filename" | sed "s/.md$//")"
        fi
    done
    echo ""
fi

if [ "$unsatisfied" == 1 ]
then
    echo "
Unsatisfied ${type} items matching id *${id}
---------------------------------------------------------------------------
"
    filenames=(${dir}/${type}-*${id}.md)
    for filename in "${filenames[@]}"
    do
        satisfied="$(cat $filename | grep -E "^Satisfied by:")"
        if [ -z "$satisfied" ]
        then
            echo "$(basename "$filename" | sed "s/.md$//")"
        fi
    done
    echo ""
fi

if [ "$unsourced" == 1 ]
then
    echo "
Unsourced ${type} items matching id *${id}
---------------------------------------------------------------------------
"
    filenames=(${dir}/${type}-*${id}.md)
    for filename in "${filenames[@]}"
    do
        is_sourced="$(cat $filename | grep -E "^Sources?:")"
        if [ -z "$is_sourced" ]
        then
            echo "$(basename "$filename" | sed "s/.md$//")"
        fi
    done
    echo ""
fi

if [ "$sourced" == "" ] && [ "$unsatisfied" == "" ] && [ "$unsourced" == "" ]
then
    echo "
All ${type} items matching id *${id}
---------------------------------------------------------------------------
"
    filenames=(${dir}/${type}-*${id}.md)
    for filename in "${filenames[@]}"
    do
        echo "$(basename "$filename" | sed "s/.md$//")"
    done
    echo ""
fi