#!/bin/bash
# sync_from_upstream.sh - Merge upstream Flowseal changes into Linux version
# Handles: proxy (HTTPS_PROXY), offline bundle, lists, .service/hosts, .service/version
# Works even if GitHub blocked (with proxy or offline bundle)

set -e

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
source "$SCRIPT_DIR/lib/download_helper.sh"

UPSTREAM_REPO="https://github.com/Flowseal/zapret-discord-youtube.git"
TMP_DIR="/tmp/zapret-upstream-$$"
LOCAL_VERSION_FILE="$SCRIPT_DIR/.service/version.txt"
STRATEGIES_DIR="$SCRIPT_DIR/strategies"

echo ""
echo "=============================================="
echo "  Upstream Sync"
echo "  Source: $UPSTREAM_REPO"
echo "=============================================="
echo ""

mkdir -p "$STRATEGIES_DIR"

# Load proxy settings
load_proxy

# Detect if offline mode requested
OFFLINE_MODE=0
if [[ "${1:-}" == "--offline" ]]; then
    OFFLINE_MODE=1
    echo "[*] OFFLINE MODE: skipping network, using local files only"
fi

REBUILD_FLAG=0
UPDATE_COUNT=0
NEW_COUNT=0

# Attempt to clone/update upstream
if [[ "$OFFLINE_MODE" -eq 0 ]]; then
    echo "[*] Cloning upstream (with fallback)..."
    if ! clone_repo_fallback "Flowseal/zapret-discord-youtube" "main" "$TMP_DIR"; then
        echo ""
        echo "[WARN] Cannot reach upstream GitHub."
        echo "    Check proxy, VPN, or prepare_offline_bundle.sh"
        echo ""
        read -rp "Continue in offline mode (skip sync)? [Y/n]: " ans
        if [[ "${ans:-Y}" == [yY]* ]]; then
            OFFLINE_MODE=1
        else
            exit 1
        fi
    fi
fi

# Read versions
LOCAL_VER=$(cat "$LOCAL_VERSION_FILE" 2>/dev/null | tr -d '[:space:]')
UPSTREAM_VER=$(cat "$TMP_DIR/.service/version.txt" 2>/dev/null | tr -d '[:space:]')
[[ -z "$LOCAL_VER" ]] && LOCAL_VER="unknown"
[[ -z "$UPSTREAM_VER" ]] && UPSTREAM_VER="unknown"

echo "Local version:    $LOCAL_VER"
echo "Upstream version: $UPSTREAM_VER"

if [[ "$UPSTREAM_VER" != "$LOCAL_VER" ]]; then
    REBUILD_FLAG=1
    echo "[*] Version changed: $LOCAL_VER → $UPSTREAM_VER"
fi

# ======================
# MERGE LISTS
# ======================
echo "[*] Merging upstream lists..."
merge_list() {
    local file="$1"
    local src=""
    if [[ -d "$TMP_DIR" ]] && [[ -f "$TMP_DIR/lists/$file" ]]; then
        src="$TMP_DIR/lists/$file"
    elif [[ -f "$SCRIPT_DIR/.bundle/$file" ]]; then
        src="$SCRIPT_DIR/.bundle/$file"
        echo "  [CACHED] lists/$file (from offline bundle)"
    else
        echo "  [SKIP] lists/$file (not available)"
        return
    fi
    cp "$src" "$SCRIPT_DIR/lists/$file"
    echo "  [OK] lists/$file"
}
merge_list "list-general.txt"
merge_list "list-google.txt"
merge_list "list-exclude.txt"
merge_list "ipset-exclude.txt"

if [[ -f "$SCRIPT_DIR/.service/ipset_filter_loaded" ]] || [[ -f "$SCRIPT_DIR/.service/ipset_filter_any" ]]; then
    merge_list "ipset-all.txt" 2>/dev/null || true
fi

# ======================
# MERGE .service/hosts + version
# ======================
echo "[*] Merging .service files..."

if [[ -d "$TMP_DIR" ]] && [[ -f "$TMP_DIR/.service/hosts" ]]; then
    cp "$TMP_DIR/.service/hosts" "$SCRIPT_DIR/.service/hosts"
    echo "  [OK] .service/hosts (GitHub, Telegram, Discord static IPs)"
    REBUILD_FLAG=1
elif [[ -f "$SCRIPT_DIR/.bundle/hosts" ]]; then
    cp "$SCRIPT_DIR/.bundle/hosts" "$SCRIPT_DIR/.service/hosts"
    echo "  [OK] .service/hosts (from offline bundle)"
    REBUILD_FLAG=1
else
    echo "  [SKIP] .service/hosts (not available)"
fi

if [[ -d "$TMP_DIR" ]] && [[ -f "$TMP_DIR/.service/version.txt" ]]; then
    echo "$UPSTREAM_VER-linux" > "$LOCAL_VERSION_FILE"
    echo "  [OK] .service/version.txt → $UPSTREAM_VER-linux"
    REBUILD_FLAG=1
fi

# ======================
# PARSE NEW .bat STRATEGIES → .conf
# ======================
echo "[*] Checking for new upstream strategies..."

parse_bat_to_conf() {
    local src="$1"
    local name_raw
    name_raw=$(basename "$src" .bat)
    local name
    name=$(echo "$name_raw" | sed -E 's/general[[:space:]]*//; s/\(|\)//g; s/^[[:space:]]+|[[:space:]]+$//g; s/ /_/g')
    [[ -z "$name" ]] && name="general"
    local conf_name="$STRATEGIES_DIR/${name}.conf"

    local raw_args
    # Join lines ending with ^, find winws.exe block
    raw_args=$(cat "$src" | tr '\n' ' ' | \
        sed 's/\^/ /g' | \
        sed -E 's/start[^"]*"[^"]*"[^"]*"[^"*]*"//i; s/ *\/min //i; s/\^//g')

    # Extract after winws.exe
    raw_args=$(echo "$raw_args" | sed -n 's/.*winws\.exe[^"]*"\?//pi')

    # Remove --wf-* (Windows-only)
    raw_args=$(echo "$raw_args" | sed -E 's/--wf-tcp=[^ "]+//g; s/--wf-udp=[^ "]+//g')

    # Normalize paths
    raw_args=$(echo "$raw_args" | sed 's|\\|/|g')
    raw_args=$(echo "$raw_args" | sed -E 's|"?%BIN%/|"%BIN%/|g; s|"?%LISTS%/|"%LISTS%/|g')

    # Replace vars
    raw_args=$(echo "$raw_args" | sed 's/%GameFilterTCP%/%GAME_TCP%/g; s/%GameFilterUDP%/%GAME_UDP%/g')

    # Split by --new into RULE1=... RULEN=...
    echo "# Strategy: $name" > "$conf_name"
    echo "# Auto-converted from upstream: $name_raw.bat" >> "$conf_name"
    echo "# Version: ${UPSTREAM_VER:-unknown}" >> "$conf_name"
    echo "" >> "$conf_name"

    local i=1
    local rule
    while IFS= read -r rule; do
        rule=$(echo "$rule" | sed 's/^[[:space:]]*//; s/[[:space:]]*$//')
        [[ -z "$rule" ]] && continue
        echo "RULE${i}=${rule}" >> "$conf_name"
        i=$((i + 1))
    done <<< "$(echo "$raw_args" | awk 'BEGIN{RS="--new"; ORS="\n"}{print}')"
}

# Only scan if upstream cloned
if [[ -d "$TMP_DIR" ]]; then
    for bat in "$TMP_DIR"/general*.bat; do
        [[ -f "$bat" ]] || continue
        bat_name=$(basename "$bat")
        [[ "$bat_name" == "service.bat" ]] && continue

        strategy_name=$(echo "$bat_name" | sed -E 's/^general[[:space:]]*//; s/\(|\)//g; s/\.bat$//; s/ /_/g')
        [[ -z "$strategy_name" ]] && strategy_name="general"
        conf_file="$STRATEGIES_DIR/${strategy_name}.conf"

        if [[ -f "$conf_file" ]]; then
            # Simple update: mark for manual review
            parse_bat_to_conf "$bat"
            UPDATE_COUNT=$((UPDATE_COUNT + 1))
            echo "  [CHANGED] Strategy updated: $bat_name → $strategy_name.conf"
            REBUILD_FLAG=1
        else
            parse_bat_to_conf "$bat"
            NEW_COUNT=$((NEW_COUNT + 1))
            echo "  [NEW] Strategy detected: $bat_name → $strategy_name.conf"
            REBUILD_FLAG=1
        fi
    done
fi

if [[ $NEW_COUNT -gt 0 ]]; then
    echo "  [INFO] $NEW_COUNT new strategy(ies) auto-converted."
    echo "  [WARN] Please verify new strategies manually before using."
fi
if [[ $UPDATE_COUNT -gt 0 ]]; then
    echo "  [INFO] $UPDATE_COUNT strategy(ies) updated from upstream."
fi
if [[ $NEW_COUNT -eq 0 ]] && [[ $UPDATE_COUNT -eq 0 ]]; then
    echo "  [OK] All strategies up to date."
fi

# Cleanup upstream clone
rm -rf "$TMP_DIR"

# ======================
# ENSURE WRAPPERS
# ======================
echo "[*] Checking strategy wrappers (general*.sh)..."
bash "$SCRIPT_DIR/ensure_wrappers.sh" 2>/dev/null || true

# ======================
# REPORT
# ======================
echo "[*] Sync complete."
if [[ "$REBUILD_FLAG" -eq 1 ]]; then
    echo "[*] REBUILD NEEDED: run ./update.sh or ./install.sh"
    exit 2
else
    echo "[*] No changes detected."
    exit 0
fi