#!/usr/bin/env bash
# Copyright 2015 Vladimir Ivanov <ivvl82@gmail.com>
# Distributed under the terms of the GNU General Public License v2

REPO_DIR=

# Specify the tournament here
TOURNAMENT=

# Version information
VERSION="0.1"

argv0=${0##*/}

# Fix the notation of decimal point
export LANG=en_US.UTF-8

function usage {
    cat <<EOF
Automatic generation of tours.
EOF

    exit "${1:-0}"
}

function version {
    exec echo "${argv0}-${VERSION}"
}

function rr_setup {
    : ${REPO_DIR:=`dirname "$0"`}
    # If no tournament given, set it to the last one
    if [[ -z $TOURNAMENT ]]; then
        local year_dir=$(ls -1 -d ${REPO_DIR}/[0-9][0-9][0-9][0-9]/ | tail -1)
        TOURNAMENT=$(ls -1 -d ${year_dir}[0-9]-*/ | tail -1 \
                            | sed -E "s|${REPO_DIR}/(.*)/|\1|")
    fi

    # Configuration file for players
    ply_ini=${REPO_DIR}/${TOURNAMENT}/players.ini
    [[ -f $ply_ini ]] || die "File ${ply_ini} not found."
    local dir_for_tours=${REPO_DIR}/${TOURNAMENT}/tours
    [[ -d $dir_for_tours ]] && die "Directory ${dir_for_tours} already exist."
}

function rr_get_names {
    declare -a TMP_NAMES
    name_re="^ *name *="
    TMP_NAMES=( $(grep "$name_re" "$ply_ini" | sed "s/${name_re}//") )

    if $RAND_ORDER; then
        # Get the set of random positions
        local max_range=$(( ${#TMP_NAMES[@]} - 1 ))
        local rand_array=( $(seq 0 1 $max_range) )
        for (( range=$max_range; range>1; --range )); do
            # Peek a random position from 0 to `range'
            local rand_value=$RANDOM
            local norm_rand_value=$(bc -l <<< "($rand_value / 32768) * $range")
            local rand_idx=$(printf "%.0f" $norm_rand_value)

            # Place the value at the position to the end of range
            local tmp=${rand_array[range]}
            rand_array[range]=${rand_array[rand_idx]}
            rand_array[rand_idx]=$tmp
        done

        # Randomize the order of players
        for (( idx=0; idx<${#rand_array[@]}; ++idx )); do
            local rand_idx=${rand_array[idx]}
            NAMES[idx]=${TMP_NAMES[rand_idx]}
        done

        echo "$(tput setaf 2)New randomized list of players:$(tput sgr0)"
        for (( idx=0; idx<${#NAMES[@]}; ++idx )); do
            echo "$(tput setaf 2)$(( idx+1 )).$(tput sgr0) ${NAMES[idx]}"
        done
        rr_update_ini
    else
        NAMES=( ${TMP_NAMES[@]} )
    fi
}

function rr_update_ini {
    local answer
    echo -n "Update 'players.ini'? (Y/n)> "
    read answer
    [[ $answer =~ ^(Y|y|Yes|yes)$ ]] || return

    # Extract INI blocks from config
    declare -a ini_array
    local ini_block=
    while read line; do
        if [[ $line =~ ^\[player[0-9]+\]$ ]]; then
            # Close the previous INI block
            if [[ -n $ini_block ]]; then
                ini_array+=( "$ini_block" )
                ini_block=
            fi
        fi

        [[ $line =~ ^\ *$ ]] || ini_block+="${line}\n"
    done <"$ply_ini"
    [[ -n $ini_block ]] && ini_array+=( "$ini_block" )

    echo "Updating ${ply_ini}..."
    mv "$ply_ini" "${ply_ini}.orig"
    for (( idx=0; idx<${#rand_array[@]}; ++idx )); do
        local rand_idx=${rand_array[idx]}
        echo -en "${ini_array[rand_idx]}" \
            | sed "s/^\[player$(( rand_idx+1 ))\]$/[player$(( idx+1 ))]/" >> "$ply_ini"
        (( idx < ${#rand_array[@]} - 1 )) && echo >> "$ply_ini"
    done
}

function rr_gen_table1 {
    local ply_num= idx= next_idx=
    # Number of table cells
    local cell_total=$(bc <<< "$PLY_MAX * ($PLY_MAX + 1)")

    # First pass: fill the table with 'PLY_MAX'
    for (( round=0; round < PLY_MAX; ++round )); do
        idx=$(bc <<< "($PLY_MAX + 1) * $round + ($round + 1) % 2")
        TABLE1[idx]=$PLY_MAX
    done

    # Second pass: fill the table with players in ascending order
    ply_num=0
    for (( pair=0; pair < cell_total/2; ++pair )); do
        idx=$(( 2 * pair ))
        next_idx=$(( 2 * pair + 1 ))
        if [[ -z ${TABLE1[idx]} ]]; then
            TABLE1[idx]=$ply_num
        else
            TABLE1[next_idx]=$ply_num
        fi

        ply_num=$(( (ply_num + 1) % PLY_MAX ))
    done

    # Second pass: fill the table with players in descending order
    ply_num=$(( PLY_MAX - 1 ))
    for (( idx=0; idx < cell_total; ++idx )); do
        if [[ -z ${TABLE1[idx]} ]]; then
            TABLE1[idx]=$ply_num
            ply_num=$(( PLY_MAX - 1 - (PLY_MAX - ply_num) % PLY_MAX ))
        fi
    done
}

function rr_gen_table2 {
    # Number of table cells
    local cell_total=$(bc <<< "$PLY_MAX * ($PLY_MAX + 1)")
    # Alter white and black players in the second half of tournament
    for (( pair=0; pair < cell_total/2; ++pair )); do
        local idx=$(( 2 * pair ))
        local next_idx=$(( 2 * pair + 1 ))
        TABLE2+=( ${TABLE1[next_idx]} ${TABLE1[idx]} )
    done
}

function rr_gen_tours {
    declare -a tour_table
    local tour_num=0 ply_num=0
    for ply in ${TABLE1[@]} ${TABLE2[@]}; do
        tour_table+=($ply)
        (( ply_num++ ))

        if (( ply_num > PLY_MAX )); then
            rr_gen_tour_info
            # Start new tour
            (( tour_num++ ))
            ply_num=0
            tour_table=()
        fi
    done
}

function rr_gen_tour_info {
    # Change tour numbers: '1' -> '01', '2' -> '02', and so on
    local tour=$(printf "%02g" $(( tour_num + 1 )))
    mkdir -p "${REPO_DIR}/${TOURNAMENT}/tours/${tour}"
    local tour_info=${REPO_DIR}/${TOURNAMENT}/tours/${tour}/tour_info
    echo "Generating ${tour_info}..."

    # Create header
    (
        echo "Тур №$(( tour_num + 1 ))"
        echo "=========="
        echo
        echo "Время проведения: ??.??.???? - ??.??.????"
        echo
    ) >> "$tour_info"

    # Create pairs
    for (( pair=0; pair < (PLY_MAX+1)/2; ++pair )); do
        local idx=$(( 2 * pair ))
        local next_idx=$(( 2 * pair + 1 ))
        local white_ply=${tour_table[idx]}
        local black_ply=${tour_table[next_idx]}
        echo "${NAMES[white_ply]} - ${NAMES[black_ply]}"
    done | column -t | sed "s/ - /-/; s/^/??.??.???? /" >> "$tour_info"
}

function die {
    echo "$@" >&2
    exit 1
}

RAND_ORDER=false
while getopts rhv opt; do
    case $opt in
        r) RAND_ORDER=true ;;
        h) usage ;;
        v) version ;;
        *) usage 1 ;;
    esac
done
shift $(( $OPTIND - 1 ))

rr_setup
declare -a NAMES
rr_get_names
# The number of players should be even
PLY_MAX=$(( ${#NAMES[@]} + ${#NAMES[@]} % 2 - 1 ))
declare -a TABLE1 TABLE2
rr_gen_table1                   # first half of tournament
rr_gen_table2                   # second half of tournament
rr_gen_tours

exit 0