#!/usr/bin/env bash
set -uo pipefail
export LC_ALL=C

wzxh="${wzxh:-182}"
export PASSWD="${PASSWD:-www.888888.games}"
yhm="${yhm:-}"
lj="${lj:-}"
OUT="${OUT:-/22}"
SOURCES="${SOURCES:-v5 v1 cdn}"
NOTOUCH="${NOTOUCH:-1}"
CONN=32
WORKERS=4
UNITS=3
FILE="/${wzxh}_all.flow6b.enc"
IDX="/${wzxh}_all.flow6b.idx"
STATE="${FILE}.st"
PREFIX="/${wzxh}_f6b"
UNITS_ORDER=(p1_0 p2_0 p3_0)
DONE="${PREFIX}.done"
FAIL="${PREFIX}.fail"
ALLQUEUED="${PREFIX}.allqueued"
WORKDONE="${PREFIX}.unpack.done"
DPID=""
WPID=""
TOTAL=0
GOT_BYTES=0

fail() {
    printf '\033[1;31m失败：%s\033[0m\n' "$1" >&2
    touch "$FAIL"
    [ -n "$DPID" ] && kill "$DPID" 2>/dev/null
    [ -n "$WPID" ] && kill "$WPID" 2>/dev/null
    exit 1
}
stop_all() {
    [ -n "$DPID" ] && kill "$DPID" 2>/dev/null
    [ -n "$WPID" ] && kill "$WPID" 2>/dev/null
    exit 130
}
trap stop_all INT TERM

[ -n "$yhm" ] || fail "请先设置 yhm"
for c in curl od dd stat openssl zstd tar awk readlink sleep tr wc mv date head dirname ln; do
    command -v "$c" >/dev/null 2>&1 || fail "缺少命令：$c"
done
# 虚拟机与非虚拟机统一：axel→aria2c→curl。
ENGINES=""
command -v axel >/dev/null 2>&1 && ENGINES="axel"
command -v aria2c >/dev/null 2>&1 && ENGINES="${ENGINES:+$ENGINES }aria2c"
ENGINES="${ENGINES:+$ENGINES }curl"
mkdir -p "$OUT" || fail "无法创建 $OUT"
OUT=$(readlink -f "$OUT") || fail "无法确认解压目录"
[ "$OUT" != "/" ] || fail "禁止直接解压到 /，请设置 OUT=/22"
printf '下载：axel -n32，32区间均优先p1_0 | 解压：3单元单队列串行 | 目录：%s\n' "$OUT"

src_url() {
    local s="$1" f="$2"
    case "$s" in
        v5) echo "https://pan1.888888.games/d/v5/${lj:+$lj/}${f}?user=${yhm}&wzxh=${wzxh}" ;;
        v1) echo "https://pan1.888888.games/d/v1/${lj:+$lj/}${f}?user=${yhm}&wzxh=${wzxh}" ;;
        cdn) echo "https://1814218554.cdn.123clouddisk.com/1814218554/d/t/${lj:+$lj/}${f}?user=${yhm}&wzxh=${wzxh}" ;;
    esac
}
[ -s "$IDX" ] || fail "缺少 $IDX，请提前手工上传"
[ "$(wc -l < "$IDX")" -eq $((CONN+UNITS)) ] || fail "索引必须为35行（32区间+3单元）"
head -n "$CONN" "$IDX" | awk 'NF!=9{exit 1}{for(i=1;i<=9;i++)if($i !~ /^[0-9]+$/)exit 1}' || fail "索引区间格式错误"
awk -F '\t' 'NR<=32{next}$1=="u"{if(NF!=5||$2!~/^p[123]$/||$3!~/^[0-9]+$/||$4!~/^[0-9]+$/||$5!~/^[0-9]+$/)exit 1;u++;next}{exit 1}END{if(u!=3)exit 1}' "$IDX" || fail "索引分片格式错误"
TOTAL=$(awk 'NR==32{print $3}' "$IDX")
SEG=$((TOTAL / CONN))
[ "$TOTAL" -gt 0 ] && [ "$SEG" -gt 0 ] || fail "整包大小无效"

declare -a SA SB
declare -A PO PL USEEN ULEN
seq=0
while read -r -a F; do
    i=${F[0]}; a=${F[1]}; b=${F[2]}
    [ "$i" -eq "$seq" ] || fail "索引序号错误"
    if [ "$i" -eq 0 ]; then ea=0; eb=$SEG; else ea=${SB[$((i-1))]}; eb=$((ea+SEG+1)); fi
    [ "$i" -eq $((CONN-1)) ] && eb=$TOTAL
    [ "$a" -eq "$ea" ] && [ "$b" -eq "$eb" ] || fail "索引与Axel 2.4区间不一致"
    [ "$a" -eq "${F[3]}" ] || fail "第$i区间起始偏移错误"
    for u in 0 1 2; do
        unit=${UNITS_ORDER[$u]}; pos=$((3+u*2)); off=${F[$pos]}; len=${F[$((pos+1))]}
        if [ "$u" -gt 0 ]; then prev=${F[$((pos-2))]}; plen=${F[$((pos-1))]}; [ "$off" -eq $((prev+plen)) ] || fail "索引物理偏移不连续"; fi
        PO["${unit}_$i"]=$off; PL["${unit}_$i"]=$len
    done
    [ "$(( ${F[7]} + ${F[8]} ))" -eq "$b" ] || fail "索引区间结束偏移错误"
    SA[$i]=$a; SB[$i]=$b; seq=$((seq+1))
done < <(head -n "$CONN" "$IDX")
while read -r mark tag i uoff ulen; do
    [ "$mark" = u ] && [ "$uoff" -eq 0 ] && [ "$ulen" -gt 0 ] || fail "分片清单错误"
    unit="${tag}_${i}"
    case " ${UNITS_ORDER[*]} " in *" $unit "*) ;; *) fail "未知分片：$unit" ;; esac
    [ "${USEEN[$unit]:-0}" -eq 0 ] || fail "重复分片：$unit"
    USEEN[$unit]=1; ULEN[$unit]=$ulen
done < <(awk -F '\t' 'NR>32 && $1=="u"' "$IDX")
[ "${#USEEN[@]}" -eq "$UNITS" ] || fail "分片数量不是3"
for unit in "${UNITS_ORDER[@]}"; do
    sum=0
    for ((i=0; i<CONN; i++)); do sum=$((sum+${PL["${unit}_$i"]})); done
    [ "$sum" -eq "${ULEN[$unit]}" ] || fail "$unit 索引总长度不一致"
done

declare -a SCUR
STATE_KIND=""
read_state() {
    local n n2 n4 i h actual kind pairs
    local -a vals
    [ -f "$STATE" ] || return 1
    actual=$(stat -c %s "$STATE" 2>/dev/null) || return 1
    n2=$(od -An -tu2 -N2 -j0 "$STATE" 2>/dev/null | tr -d ' ') || return 1
    n4=$(od -An -tu4 -N4 -j0 "$STATE" 2>/dev/null | tr -d ' ') || return 1
    n=0; h=0; kind=""; pairs=2
    if [[ "$n4" =~ ^[0-9]+$ ]] && [ "$n4" -eq "$CONN" ] && [ "$actual" -eq "$((12+16*n4))" ]; then n=$n4; h=4; kind=new4
    elif [[ "$n2" =~ ^[0-9]+$ ]] && [ "$n2" -eq "$CONN" ] && [ "$actual" -eq "$((10+16*n2))" ]; then n=$n2; h=2; kind=new2
    elif [[ "$n4" =~ ^[0-9]+$ ]] && [ "$n4" -eq "$CONN" ] && [ "$actual" -eq "$((12+8*n4))" ]; then n=$n4; h=4; kind=old4; pairs=1
    elif [[ "$n2" =~ ^[0-9]+$ ]] && [ "$n2" -eq "$CONN" ] && [ "$actual" -eq "$((10+8*n2))" ]; then n=$n2; h=2; kind=old2; pairs=1
    else return 1
    fi
    case "$kind" in old4|old2) ;; *) return 1 ;; esac
    vals=($(od -An -v -tu8 -j"$h" "$STATE" 2>/dev/null)) || return 1
    ((${#vals[@]} >= 1+pairs*n)) || return 1
    GOT_BYTES=${vals[0]}
    for ((i=0; i<n; i++)); do SCUR[$i]=${vals[$((1+pairs*i))]}; done
    STATE_KIND=$kind
    return 0
}
SP=0
slot_progress() {
    local i=$1 cur=${SCUR[$1]} a=${SA[$1]} b=${SB[$1]}
    if ((cur<a || cur>=b)); then SP=$b; else SP=$cur; fi
}
unit_ready() {
    local unit=$1 i off len need
    for ((i=0; i<CONN; i++)); do
        off=${PO["${unit}_$i"]}; len=${PL["${unit}_$i"]}
        [ "$len" -gt 0 ] || continue
        need=$((off+len)); slot_progress "$i"
        [ "$SP" -ge "$need" ] || return 1
    done
    return 0
}
emit_unit() {
    local unit=$1 i off len
    for ((i=0; i<CONN; i++)); do
        off=${PO["${unit}_$i"]}; len=${PL["${unit}_$i"]}
        [ "$len" -gt 0 ] || continue
        dd if="$FILE" bs=1M iflag=skip_bytes,count_bytes skip="$off" count="$len" status=none
    done
}
TAR_OPTS="--no-xattrs --no-acls --no-selinux --delay-directory-restore"
[ "$NOTOUCH" = 1 ] && TAR_OPTS="$TAR_OPTS -m"
unpack_unit() {
    local unit=$1 base="${PREFIX}_${1}" rc
    date +%s%N > "${base}.start"
    emit_unit "$unit" 2>"${base}.err" |
        openssl enc -d -aes-256-ctr -md sha256 -pass env:PASSWD 2>>"${base}.err" |
        zstd -d 2>>"${base}.err" |
        tar --extract --preserve-permissions --file=- --directory="$OUT" $TAR_OPTS 2>>"${base}.err"
    rc=$?
    date +%s%N > "${base}.end"
    echo "$rc" > "${base}.rc"
    [ "$rc" -eq 0 ] || touch "$FAIL"
    return "$rc"
}
if [ -f "$FILE" ] && [ ! -f "$STATE" ]; then mv -f "$FILE" "${FILE}.previous"; fi
if [ ! -f "$FILE" ] && [ -f "$STATE" ]; then mv -f "$STATE" "${STATE}.previous"; fi
rm -f "$DONE" "$FAIL" "$ALLQUEUED" "$WORKDONE" "${PREFIX}.dltime" "${PREFIX}.rc" "${PREFIX}.engine" "${PREFIX}_download.err"
for unit in "${UNITS_ORDER[@]}"; do
    base="${PREFIX}_${unit}"
    rm -f "${base}.job" "${base}.ready" "${base}.started" "${base}.start" "${base}.end" "${base}.rc" "${base}.err"
done
printf 'save_state_interval = 0\n' > /.axelrc
AXEL_VER="Axel未安装"; command -v axel >/dev/null 2>&1 && AXEL_VER=$(axel -V 2>&1 | head -n 1)
pv5u=$(src_url v5 "$(basename "$FILE")"); curl -ksS --connect-timeout 10 --max-time 20 -o /dev/null -w '%{redirect_url}' "$pv5u" > "/${wzxh}_flow6b.v5.url" 2>/dev/null
START_NS=$(date +%s%N)
STATE_PARSE_FIRST=0
STATE_BAD=0

(
    rc=1
    for s in $SOURCES; do
        u=$(src_url "$s" "$(basename "$FILE")")
        for engine in $ENGINES; do
            echo "下载源：$s"
            case "$engine" in
                axel)
                    if [ -f "$FILE" ] && [ ! -f "$STATE" ]; then mv -f "$FILE" "${FILE}.previous"; fi
                    au=$(cat /182_flow6b.$s.url 2>/dev/null); [ -n "$au" ] || au=$(curl -ksS --connect-timeout 10 --max-time 20 -o /dev/null -w '%{redirect_url}' "$u" 2>>"${PREFIX}_download.err")
                    [ -n "$au" ] || au="$u"
                    HOME=/ axel -n 32 -q -o "$FILE" "$au" 2>>"${PREFIX}_download.err"
                    arc=$?
                    ;;
                aria2c)
                    if [ -f "$STATE" ]; then
                        [ ! -f "$FILE" ] || mv -f "$FILE" "${FILE}.previous"
                        mv -f "$STATE" "${STATE}.previous"
                    fi
                    aria2c -c -x16 -s16 -k1M --min-split-size=1M --max-connection-per-server=16 \
                        --allow-overwrite=true --auto-file-renaming=false \
                        -d "$(dirname "$FILE")" -o "$(basename "$FILE")" "$u" >>"${PREFIX}_download.err" 2>&1
                    arc=$?
                    ;;
                curl)
                    if [ -f "$STATE" ] || [ -f "${FILE}.aria2" ]; then rm -f "$FILE" "$STATE" "${FILE}.aria2"; fi
                    curl -fksSL -C - --retry 1 --connect-timeout 10 --max-time 0 \
                        -o "$FILE" "$u" 2>>"${PREFIX}_download.err"
                    arc=$?
                    ;;
            esac
            sz=0
            [ -f "$FILE" ] && sz=$(stat -c %s "$FILE" 2>/dev/null || echo 0)
            if [ "$arc" -eq 0 ] && [ "$sz" -eq "$TOTAL" ]; then
                echo "$engine" > "${PREFIX}.engine"
                rc=0
                break 2
            fi
            echo "当前工具或源失败，尝试下一项..." >&2
        done
    done
    if [ "$rc" -eq 0 ]; then date +%s%N > "${PREFIX}.dltime"; touch "$DONE"; else touch "$FAIL"; fi
    echo "$rc" > "${PREFIX}.rc"
    exit "$rc"
) &
DPID=$!

# 单队列串行：p1→p2→p3。Axel支持边下边解压，aria2c/curl回退时等待整包下载完成。
(
    for unit in "${UNITS_ORDER[@]}"; do
        base="${PREFIX}_${unit}"
        while [ ! -f "${base}.job" ]; do
            [ ! -f "$FAIL" ] || exit 1
            sleep 0.005
        done
        : > "${base}.started"
        unpack_unit "$unit" || exit 1
    done
    touch "$WORKDONE"
) &
WPID=$!

queued=0
declare -A QUEUED
while [ "$queued" -lt "$UNITS" ]; do
    [ ! -f "$FAIL" ] || fail "任务失败；下载日志 ${PREFIX}_download.err，分片日志 ${PREFIX}_p*_*.err"
    can_check=0
    if [ -f "$DONE" ]; then can_check=1
    elif read_state; then
        can_check=1
        [ "$STATE_PARSE_FIRST" -gt 0 ] || STATE_PARSE_FIRST=$(date +%s%N)
    else STATE_BAD=$((STATE_BAD+1)); fi
    if [ "$can_check" -eq 1 ]; then
        for unit in "${UNITS_ORDER[@]}"; do
            [ "${QUEUED[$unit]:-0}" -eq 0 ] || continue
            if [ -f "$DONE" ] || unit_ready "$unit"; then
                base="${PREFIX}_${unit}"
                date +%s%N > "${base}.ready"
                : > "${base}.job"
                QUEUED[$unit]=1; queued=$((queued+1))
            fi
        done
    fi
    [ "$queued" -eq "$UNITS" ] || sleep 0.01
done
touch "$ALLQUEUED"
wait "$DPID"; DRC=$?; DPID=""
[ "$DRC" -eq 0 ] || fail "下载失败"
wait "$WPID"; WRC=$?; WPID=""
[ "$WRC" -eq 0 ] && [ -f "$WORKDONE" ] || fail "后台分片解压失败"
END_NS=$(date +%s%N)
DL_NS=$(cat "${PREFIX}.dltime")
FIRST_START=0; LAST_END=0; XSUM_NS=0; EARLY=0
for unit in "${UNITS_ORDER[@]}"; do
    base="${PREFIX}_${unit}"
    xs=$(cat "${base}.start"); xe=$(cat "${base}.end")
    [ "$FIRST_START" -gt 0 ] && [ "$xs" -ge "$FIRST_START" ] || FIRST_START=$xs
    [ "$xe" -le "$LAST_END" ] || LAST_END=$xe
    XSUM_NS=$((XSUM_NS+xe-xs))
    [ "$xe" -ge "$DL_NS" ] || EARLY=$((EARLY+1))
done
DL_SEC=$(awk -v n="$((DL_NS-START_NS))" 'BEGIN{printf "%.3f",n/1e9}')
ALL_SEC=$(awk -v n="$((END_NS-START_NS))" 'BEGIN{printf "%.3f",n/1e9}')
TAIL_SEC=$(awk -v n="$((END_NS-DL_NS))" 'BEGIN{printf "%.3f",n/1e9}')
XWALL_SEC=$(awk -v n="$((LAST_END-FIRST_START))" 'BEGIN{printf "%.3f",n/1e9}')
FIRST_SEC=$(awk -v n="$((FIRST_START-START_NS))" 'BEGIN{printf "%.3f",n/1e9}')
printf '\033[1;32m首次解压：%ss | 解压墙钟：%ss | 下载后尾长：%ss | 下载：%ss | 总耗时：%ss | 输出：%s\033[0m\n' "$FIRST_SEC" "$XWALL_SEC" "$TAIL_SEC" "$DL_SEC" "$ALL_SEC" "$OUT"
rm -f /"${wzxh}"_* /.axelrc