#!/bin/bash
# ==============================================================================================
# ================================= Git Pull & Execute =========================================
# ==============================================================================================
# Pulls the latest scripts from the Gitea repository via SSH.
# Lives at the repo root — sources load_config.sh from the same directory.
#
# ── WHAT THIS SCRIPT DOES ─────────────────────────────────────────────────────────────────────
# 1. Detects which server it's running on via detect_hosts() (MY_ID)
# 2. Configures sparse checkout to exclude other servers' credential files
#    Each server only pulls its own master_host*.conf — never sees peer credentials
# 3. Pulls or clones latest scripts from Gitea
# 4. Sets executable permissions on all .sh files
#
# ── SPARSE CHECKOUT ───────────────────────────────────────────────────────────────────────────
# Sparse checkout ensures each server only receives its own host conf:
#   HOST1 pulls:  master.conf + master_host1.conf + all scripts
#   HOST1 skips:  master_host2.conf, master_host3.conf etc.
#   HOST2 pulls:  master.conf + master_host2.conf + all scripts
#   HOST2 skips:  master_host1.conf, master_host3.conf etc.
#
# Adding a new server:
#   Create master_host3.conf in the repo
#   All existing servers automatically exclude it on next pull
#   New server gets only its own conf ✅
#
# ── GITEA LOCATION DETECTION ──────────────────────────────────────────────────────────────────
# Detects where Gitea is running at runtime — works through failover:
#   Gitea local  → connects via local IP
#   Gitea remote → connects via Tailscale IP
#   Both fail    → falls back to GITEA_DOMAIN if configured
#
# ── CONFIGURATION (master.conf) ───────────────────────────────────────────────────────────────
#   GITEA_CONTAINER  — Docker container name for Gitea
#   GITEA_REPO_PATH  — repo path on Gitea (e.g. FailedProxy/Unraid_Scripts.git)
#   GITEA_DOMAIN     — public domain fallback (optional)
#   TARGET_DIR       — local path to clone/pull into
#   GITEA_SSH_KEY    — SSH key for Gitea authentication
#   SSH_PORT         — Gitea SSH port (often 221 or 222)
#
# ── USAGE ─────────────────────────────────────────────────────────────────────────────────────
#   git_pull_execute.sh              — normal pull
#   git_pull_execute.sh --dry-run    — preview without making changes
#   git_pull_execute.sh --log        — verbose output
#   git_pull_execute.sh --status     — show config and exit
# ==============================================================================================

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"

# Root level script — load_config.sh is in the same directory
source "$SCRIPT_DIR/load_config.sh"

parse_args "$@"

# ==============================================================================================
# ━━━ Setup ━━━
# ==============================================================================================
echo ""
echo "━━━ $ICON_GEAR Setup ━━━"

if [[ "$EUID" -ne 0 ]]; then
    error "Must be run as root"
    exit 1
fi
acquire_lock

# detect_hosts() sets MY_ID — needed for sparse checkout configuration
detect_hosts

# ==============================================================================================
# ━━━ Locate Gitea ━━━
# ==============================================================================================
echo ""
echo "━━━ $ICON_CONTAINERS Locate Gitea ━━━"

if docker ps --format "{{.Names}}" 2>/dev/null | grep -q "^${GITEA_CONTAINER}$"; then
    # Gitea is running on this server — use local IP
    GITEA_IP=$(hostname -I | awk '{print $1}')
    log "Gitea running locally — connecting via $GITEA_IP"
else
    # Gitea not running locally — find it on the remote server via Tailscale
    log "Gitea not running locally — checking remote server"
    GITEA_IP=$(tailscale ip -4 "${REMOTE_SERVER_NAME,,}" 2>/dev/null)
    if [[ -n "$GITEA_IP" ]]; then
        echo "  Gitea on $REMOTE_SERVER_NAME — connecting via Tailscale $GITEA_IP"
    elif [[ -n "${GITEA_DOMAIN:-}" ]]; then
        warn "Tailscale resolution failed — falling back to $GITEA_DOMAIN"
        GITEA_IP="$GITEA_DOMAIN"
    else
        error "Cannot find Gitea — local: not running, Tailscale: failed, domain: not configured"
        notify "Git pull failed on $(hostname) — cannot locate Gitea container" "Git Sync" "alert"
        exit 1
    fi
fi

REPO_SSH="git@${GITEA_IP}:${GITEA_REPO_PATH}"

require_var REPO_SSH
require_var TARGET_DIR
require_var GITEA_SSH_KEY
require_var SSH_PORT

# ==============================================================================================
# ━━━ Status ━━━
# ==============================================================================================
if [[ "$SHOW_STATUS" == true ]]; then
    echo ""
    echo "━━━━━ $ICON_SUMMARY STATUS ━━━━━"
    echo "$ICON_NET  Repo:        $REPO_SSH"
    echo "$ICON_GEAR Target:      $TARGET_DIR"
    echo "$ICON_GEAR SSH Key:     $GITEA_SSH_KEY"
    echo "$ICON_GEAR SSH Port:    $SSH_PORT"
    echo "$ICON_HOST My ID:       $MY_ID ($LOCAL_SERVER_NAME)"
    echo "$ICON_HOST Remote ID:   $REMOTE_ID ($REMOTE_SERVER_NAME)"
    echo "$ICON_NOTIFY Notify:    unRAID=${NOTIFY_UNRAID:-false} Discord=$([[ -n "${MY_DISCORD_WEBHOOK:-}" ]] && echo enabled || echo disabled)"
    echo "$ICON_GEAR Dry Run:     $DRY_RUN"
    echo "━━━━━━━━━━━━━━━━━━━━━━━"
    exit 0
fi

[[ "$DRY_RUN" == true ]] && warn "DRY RUN — no changes will be made"

# ==============================================================================================
# ━━━ Sparse Checkout Configuration ━━━
# ==============================================================================================
# Build the list of master_host*.conf files that belong to OTHER servers.
# This server pulls everything EXCEPT those files.
# MY_ID is set by detect_hosts() — e.g. "HOST1"

configure_sparse_checkout() {
    local repo_dir="$1"

    log "Configuring sparse checkout for $MY_ID..."

    # Enable sparse checkout
    git -C "$repo_dir" config core.sparseCheckout true 2>/dev/null

    # Build exclusion list — all master_host*.conf files except MY_ID's
    local sparse_file="$repo_dir/.git/info/sparse-checkout"
    mkdir -p "$(dirname "$sparse_file")"

    # Start with: pull everything
    echo "/*" > "$sparse_file"

    # Exclude each other server's conf file
    # Find all master_host*.conf files present in the repo
    local excluded=0
    for conf_file in "$repo_dir"/master_host*.conf; do
        [[ -f "$conf_file" ]] || continue
        local conf_name
        conf_name=$(basename "$conf_file")

        # Determine which HOST ID owns this conf by grepping its hostname var
        # Pattern: HOST1="unRAID-..." or HOST2="unRAID-..."
        local conf_host_id
        conf_host_id=$(grep -m1 -oP '^\s+HOST[0-9]+(?==)' "$conf_file" 2>/dev/null | tr -d ' ')

        if [[ -z "$conf_host_id" ]]; then
            log "Cannot determine HOST ID for $conf_name — including in pull (safe default)"
            continue
        fi

        if [[ "$conf_host_id" != "$MY_ID" ]]; then
            echo "!$conf_name" >> "$sparse_file"
            log "Sparse checkout: excluding $conf_name (belongs to $conf_host_id)"
            ((excluded++))
        else
            log "Sparse checkout: including $conf_name (belongs to $MY_ID — this server)"
        fi
    done

    if [[ "$excluded" -gt 0 ]]; then
        echo "  Sparse checkout: excluding $excluded peer conf file(s) — credentials protected"
    else
        log "Sparse checkout: no peer conf files to exclude (single server or first run)"
    fi
}

# ==============================================================================================
# ━━━ Git Sync ━━━
# ==============================================================================================
echo ""
echo "━━━ $ICON_SYNC Git Sync ━━━"
echo "$ICON_NET  Repo:    $REPO_SSH"
echo "$ICON_GEAR Target:  $TARGET_DIR"
echo ""

START=$(date +%s)
SYNC_SUCCESS=false

if [[ "$DRY_RUN" == true ]]; then
    warn "DRY RUN — would sync $REPO_SSH → $TARGET_DIR"
    warn "DRY RUN — would configure sparse checkout for $MY_ID"
    warn "DRY RUN — would exclude peer master_host*.conf files"
    SYNC_SUCCESS=true
else
    mkdir -p "$TARGET_DIR"
    git config --global --add safe.directory "$TARGET_DIR"
    cd "$TARGET_DIR" || { error "Cannot cd into $TARGET_DIR"; exit 1; }

    if [[ -d ".git" ]]; then
        # ── Existing repository ──────────────────────────────────────────────
        echo "  Existing repository — updating"

        # Configure sparse checkout BEFORE pull
        # Uses conf files already present from last pull to determine exclusions
        configure_sparse_checkout "$TARGET_DIR"

        log "git reset --hard"
        git reset --hard

        log "git clean -fd"
        git clean -fd

        echo "  Pulling latest changes..."
        if GIT_SSH_COMMAND="ssh -i $GITEA_SSH_KEY -p $SSH_PORT" git pull; then
            echo "  Git pull successful"
            SYNC_SUCCESS=true
        else
            error "Git pull failed"
            notify "Git pull failed on $(hostname) — check Gitea connectivity" "Git Sync" "alert"
            exit 1
        fi

    else
        # ── Fresh clone ──────────────────────────────────────────────────────
        echo "  No repository found — cloning"

        # Clone first — need the repo to exist before configuring sparse checkout
        if GIT_SSH_COMMAND="ssh -i $GITEA_SSH_KEY -p $SSH_PORT" git clone "$REPO_SSH" .; then
            echo "  Clone successful"

            # Configure sparse checkout after clone
            # Now all master_host*.conf files are present — can detect exclusions
            configure_sparse_checkout "$TARGET_DIR"

            # Apply sparse checkout — removes excluded files from working tree
            echo "  Applying sparse checkout..."
            git read-tree -mu HEAD
            echo "  Sparse checkout applied — peer credentials removed from working tree"

            SYNC_SUCCESS=true
        else
            error "Clone failed"
            notify "Git clone failed on $(hostname) — check Gitea connectivity" "Git Sync" "alert"
            exit 1
        fi
    fi

    # ── Permissions ──────────────────────────────────────────────────────────
    echo ""
    echo "━━━ $ICON_GEAR Permissions ━━━"
    log "Setting executable permissions on all .sh files..."
    find "$TARGET_DIR" -type f -name "*.sh" -exec chmod +x {} \;
    echo "  Permissions set on .sh files"
fi

END=$(date +%s)

# ==============================================================================================
# ━━━ Summary ━━━
# ==============================================================================================
echo ""
echo "━━━━━ $ICON_SUMMARY GIT SYNC SUMMARY ━━━━━"
echo "$ICON_NET  Repo:     $REPO_SSH"
echo "$ICON_GEAR Target:   $TARGET_DIR"
echo "$ICON_HOST Identity: $MY_ID ($LOCAL_SERVER_NAME)"
echo "$ICON_LOCK Excluded: peer master_host*.conf files"
echo "$ICON_TIME Duration: $(format_duration $((END - START)))"
if [[ "$DRY_RUN" == true ]]; then
    echo "$ICON_WARN Status:   DRY RUN — no changes made"
elif [[ "$SYNC_SUCCESS" == true ]]; then
    echo "$ICON_DONE Status:   $ICON_SUCCESS DONE"
    notify "Repository synced successfully on $(hostname)" "Git Sync" "normal"
else
    echo "$ICON_ERROR Status:  $ICON_ERROR FAILED"
fi
echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"