#!/usr/bin/env bash
# hermes-wiki-serve.sh — Hermes Wiki via obsidian-web-viewer + Tailscale
#
# Was dieses Skript tut:
#   - Klont DanielCheer/obsidian-web-viewer einmalig nach ~/.local/share/hermes-wiki/owv/
#   - Startet deren server.py (Python stdlib) auf 127.0.0.1:8765 (Loopback)
#   - Aktiviert tailscale serve, der den Loopback-Port als https im Tailnet exponen lässt
#   - Liefert File-Tree, 3D-Graph, Volltext-Suche, WikiLink-Navigation out-of-the-box
#
# Verwendung:
#   hermes-wiki-serve.sh start      # Server starten (klont obv beim ersten Mal)
#   hermes-wiki-serve.sh stop       # Server stoppen
#   hermes-wiki-serve.sh restart    # stop + start
#   hermes-wiki-serve.sh status     # Process-Status, Health-Check, Tailscale-URL
#   hermes-wiki-serve.sh logs       # tail -f der Log-Files
#   hermes-wiki-serve.sh install    # nur das Clonen/Update, kein Server-Start
#   hermes-wiki-serve.sh --help
#
# Umgebungsvariablen:
#   HERMES_WIKI_PORT=8765           Lokaler HTTP-Port (Loopback)
#   HERMES_WIKI_DIR=/home/admin/my-karpathy-wiki
#   HERMES_WIKI_LOG_DIR=$HOME/.local/share/hermes-wiki/log
#   HERMES_WIKI_TS=auto            auto|yes|no — Tailscale serve aktivieren
#   HERMES_WIKI_TS_PATH=             leer=Root-Prefix (default), /wiki=unter-Pfad
#   HERMES_WIKI_OWV_DIR=$HOME/repos/hermes-wiki-viewer  (Lukas-Fork default; upstream obv als Fallback)

set -euo pipefail

# ---------------------------------------------------------------------------
# Defaults
# ---------------------------------------------------------------------------
readonly HERMES_WIKI_PORT="${HERMES_WIKI_PORT:-8765}"
readonly HERMES_WIKI_DIR="${HERMES_WIKI_DIR:-/home/admin/my-karpathy-wiki}"
readonly HERMES_WIKI_LOG_DIR="${HERMES_WIKI_LOG_DIR:-$HOME/.local/share/hermes-wiki/log}"
readonly HERMES_WIKI_TS="${HERMES_WIKI_TS:-auto}"
readonly HERMES_WIKI_TS_PATH="${HERMES_WIKI_TS_PATH:-}"  # leer = Root-Prefix (obv nutzt relative URLs!)
readonly HERMES_WIKI_OWV_DIR="${HERMES_WIKI_OWV_DIR:-$HOME/repos/hermes-wiki-viewer}"
readonly HERMES_WIKI_REPO="${HERMES_WIKI_REPO:-}"  # leer = lokales Lukas-Repo nutzen
readonly OWV_REPO_UPSTREAM="https://github.com/DanielCheer/obsidian-web-viewer.git"
readonly PID_FILE="/tmp/hermes-wiki-serve.pid"
readonly HEALTH_URL="http://127.0.0.1:${HERMES_WIKI_PORT}/api/vault/tree"

# ---------------------------------------------------------------------------
# Helpers
# ---------------------------------------------------------------------------
log() {
    printf '[%s] %s\n' "$(date +%H:%M:%S)" "$*" | tee -a "$HERMES_WIKI_LOG_DIR/server.log" >&2
}

die() {
    log "ERROR: $*"
    exit 1
}

ensure_dirs() {
    mkdir -p "$HERMES_WIKI_LOG_DIR" || die "Kann Log-Dir nicht erstellen: $HERMES_WIKI_LOG_DIR"
}

require_tools() {
    command -v python3 >/dev/null || die "python3 nicht gefunden"
    command -v git     >/dev/null || die "git nicht gefunden"
    [ -d "$HERMES_WIKI_DIR" ] || die "Wiki-Verzeichnis nicht gefunden: $HERMES_WIKI_DIR"
}

detect_tailscale() {
    [ "$HERMES_WIKI_TS" != "no" ] || return 1
    command -v tailscale >/dev/null || return 1
    tailscale status --json >/dev/null 2>&1 || return 1
    return 0
}

# ---------------------------------------------------------------------------
# Installation: Repo klonen oder updaten
# ---------------------------------------------------------------------------
install_repo() {
    # Mode 1: Lokales Lukas-Repo (~/repos/hermes-wiki-viewer/) — default nach Fork
    if [ -d "$HERMES_WIKI_OWV_DIR/.git" ] && [ -z "$HERMES_WIKI_REPO" ]; then
        log "Nutze lokales Lukas-Repo: $HERMES_WIKI_OWV_DIR"
        (cd "$HERMES_WIKI_OWV_DIR" && git pull --ff-only 2>>"$HERMES_WIKI_LOG_DIR/install.log") || \
            log "WARN: git pull fehlgeschlagen — nutze Working-Tree-Stand"
    # Mode 2: Remote Lukas-Repo klonen (z.B. wenn HERMES_WIKI_REPO gesetzt)
    elif [ -n "$HERMES_WIKI_REPO" ]; then
        if [ -d "$HERMES_WIKI_OWV_DIR/.git" ]; then
            log "Update Lukas-Fork in $HERMES_WIKI_OWV_DIR"
            (cd "$HERMES_WIKI_OWV_DIR" && git pull --ff-only 2>>"$HERMES_WIKI_LOG_DIR/install.log") || \
                log "WARN: git pull fehlgeschlagen"
        else
            log "Klone Lukas-Fork $HERMES_WIKI_REPO nach $HERMES_WIKI_OWV_DIR"
            git clone "$HERMES_WIKI_REPO" "$HERMES_WIKI_OWV_DIR" 2>>"$HERMES_WIKI_LOG_DIR/install.log" || \
                die "git clone fehlgeschlagen — Repo-URL korrekt?"
        fi
    # Mode 3: Fallback — upstream obv direkt (vor Lukas-Fork)
    else
        log "Kein Lukas-Repo gefunden, klone upstream obv nach $HERMES_WIKI_OWV_DIR"
        log "(Für Lukas-Customizations: HERMES_WIKI_OWV_DIR=/path/to/hermes-wiki-viewer setzen)"
        git clone "$OWV_REPO_UPSTREAM" "$HERMES_WIKI_OWV_DIR" 2>>"$HERMES_WIKI_LOG_DIR/install.log" || \
            die "git clone fehlgeschlagen"
    fi

    # requirements.txt: nur PyYAML (optional). Stdlib reicht für unsere Zwecke.
    if ! python3 -c "import yaml" 2>/dev/null; then
        log "PyYAML nicht installiert (optional). Installiere..."
        python3 -m pip install --user --quiet PyYAML 2>>"$HERMES_WIKI_LOG_DIR/install.log" || \
            log "WARN: PyYAML-Installation fehlgeschlagen — Frontmatter wird rudimentär behandelt"
    fi
    log "Wiki-Viewer bereit in $HERMES_WIKI_OWV_DIR"
}

# ---------------------------------------------------------------------------
# Tailscale-Integration
# ---------------------------------------------------------------------------
start_tailscale() {
    detect_tailscale || {
        [ "$HERMES_WIKI_TS" = "no" ] || \
            log "Tailscale übersprungen (nicht verfügbar oder HERMES_WIKI_TS=$HERMES_WIKI_TS)"
        return 0
    }

    if tailscale serve status --bg 2>/dev/null | grep -q "$HERMES_WIKI_PORT"; then
        log "Tailscale serve bereits aktiv für Port $HERMES_WIKI_PORT"
        return 0
    fi

    log "Starte tailscale serve auf Root-Prefix -> 127.0.0.1:$HERMES_WIKI_PORT"
    local ts_path_arg=()
    if [ -n "$HERMES_WIKI_TS_PATH" ]; then
        ts_path_arg=(--set-path="$HERMES_WIKI_TS_PATH")
        log "(Tailscale wird unter /$HERMES_WIKI_TS_PATH/ exposen — Achtung: obv nutzt relative URLs!)"
    fi
    if tailscale serve --bg --https=443 "${ts_path_arg[@]}" \
         "http://127.0.0.1:$HERMES_WIKI_PORT" 2>>"$HERMES_WIKI_LOG_DIR/tailscale.log"; then
        local ts_url
        ts_url=$(tailscale serve status --json 2>/dev/null | python3 -c "
import json, sys
try:
    data = json.load(sys.stdin)
    for entry in data.get('Web', {}).values():
        print(f'https://{entry[\"HTTPS\"]}{entry[\"Path\"]}/')
        break
except: pass
" 2>/dev/null)
        log "Tailscale serve aktiv: ${ts_url:-URL konnte nicht ermittelt werden}"
        return 0
    else
        log "WARN: tailscale serve fehlgeschlagen — siehe $HERMES_WIKI_LOG_DIR/tailscale.log"
        return 0
    fi
}

stop_tailscale() {
    detect_tailscale || return 0
    if tailscale serve status --bg 2>/dev/null | grep -q "$HERMES_WIKI_PORT"; then
        log "Stoppe tailscale serve"
        tailscale serve --bg --https=443 --set-path="$HERMES_WIKI_TS_PATH" off \
            "http://127.0.0.1:$HERMES_WIKI_PORT" 2>>"$HERMES_WIKI_LOG_DIR/tailscale.log" || true
    fi
}

# ---------------------------------------------------------------------------
# Server-Lifecycle
# ---------------------------------------------------------------------------
is_running() {
    [ -f "$PID_FILE" ] || return 1
    local pid
    pid=$(cat "$PID_FILE" 2>/dev/null || echo "")
    [ -n "$pid" ] && kill -0 "$pid" 2>/dev/null
}

start_server() {
    ensure_dirs
    require_tools
    install_repo

    if is_running; then
        log "Server läuft bereits (PID $(cat "$PID_FILE"))"
        return 0
    fi

    # Port-Konflikt-Check
    if ss -tln 2>/dev/null | grep -q ":${HERMES_WIKI_PORT} "; then
        die "Port ${HERMES_WIKI_PORT} ist bereits belegt. HERMES_WIKI_PORT ändern oder Prozess beenden."
    fi

    # Check, dass die Wiki-Page gerendert werden kann
    local md_count
    md_count=$(find "$HERMES_WIKI_DIR" -name "*.md" -not -path "*/raw/*" 2>/dev/null | wc -l)
    log "Wiki-Dir: $HERMES_WIKI_DIR ($md_count .md-Dateien, ohne /raw/)"

    # Server starten — Loopback only, NICHT 0.0.0.0
    log "Starte obsidian-web-viewer server.py auf 127.0.0.1:$HERMES_WIKI_PORT"
    nohup python3 "$HERMES_WIKI_OWV_DIR/server.py" \
        --vault "$HERMES_WIKI_DIR" \
        --host 127.0.0.1 \
        --port "$HERMES_WIKI_PORT" \
        > "$HERMES_WIKI_LOG_DIR/renderer.log" 2>&1 &
    local pid=$!
    echo "$pid" > "$PID_FILE"

    # Health-Check (das Tool hat keine /__health, aber /api/vault/tree ist immer da)
    local i
    for i in 1 2 3 4 5; do
        sleep 1
        if curl -sf "$HEALTH_URL" >/dev/null 2>&1; then
            log "Server gestartet (PID $pid), Health-Check OK"
            start_tailscale
            return 0
        fi
    done

    log "ERROR: Health-Check fehlgeschlagen nach 5s"
    log "--- renderer.log ---"
    tail -20 "$HERMES_WIKI_LOG_DIR/renderer.log" >&2
    rm -f "$PID_FILE"
    return 1
}

stop_server() {
    if is_running; then
        local pid
        pid=$(cat "$PID_FILE")
        log "Stoppe Server (PID $pid)"
        kill "$pid" 2>/dev/null || true
        local i
        for i in 1 2 3 4 5; do
            kill -0 "$pid" 2>/dev/null || break
            sleep 0.5
        done
        if kill -0 "$pid" 2>/dev/null; then
            kill -9 "$pid" 2>/dev/null || true
        fi
        rm -f "$PID_FILE"
    fi
    # Tailscale NICHT stoppen — soll laufen bleiben für Re-Start ohne Tailscale-Re-Init
    # stop_tailscale
    log "(Tailscale serve bleibt aktiv für Re-Start)"
}

# ---------------------------------------------------------------------------
# Status / Help
# ---------------------------------------------------------------------------
show_status() {
    echo "=== Hermes Wiki Server Status (via obsidian-web-viewer) ==="
    echo "Wiki-Dir:    $HERMES_WIKI_DIR"
    echo "Viewer-Repo: $HERMES_WIKI_OWV_DIR"
    echo "Port:        $HERMES_WIKI_PORT (Loopback only)"
    echo "Log-Dir:     $HERMES_WIKI_LOG_DIR"

    if is_running; then
        local pid
        pid=$(cat "$PID_FILE")
        echo "Status:      RUNNING (PID $pid)"
        ps -o pid,rss,etime,cmd -p "$pid" 2>/dev/null | tail -1 | \
            awk '{printf "             Memory: %.1f MB, Uptime: %s\n", $2/1024, $3}'

        if curl -sf "$HEALTH_URL" >/dev/null 2>&1; then
            local md_count
            md_count=$(curl -sf "$HEALTH_URL" | python3 -c "
import json, sys
try:
    data = json.load(sys.stdin)
    count = sum(1 + len(c.get('children',[])) for c in [data])
    # grobe zählung
    print(len(json.dumps(data)))
except: print('?')
" 2>/dev/null || echo "?")
            echo "Health:      OK (Tree-API reachable, $md_count bytes)"
        else
            echo "Health:      FAILED"
        fi

        if detect_tailscale; then
            if tailscale serve status --bg 2>&1 | grep -q "$HERMES_WIKI_PORT"; then
                local ts_url
                ts_url=$(tailscale serve status --json 2>/dev/null | python3 -c "
import json, sys
try:
    data = json.load(sys.stdin)
    for entry in data.get('Web', {}).values():
        print(f'https://{entry[\"HTTPS\"]}{entry[\"Path\"]}/')
        break
except: pass
" 2>/dev/null)
                echo "Tailscale:   AKTIV — ${ts_url:-URL nicht extrahierbar}"
            else
                echo "Tailscale:   nicht aktiv für Port $HERMES_WIKI_PORT (HERMES_WIKI_TS=$HERMES_WIKI_TS)"
            fi
        else
            echo "Tailscale:   nicht verfügbar oder deaktiviert"
        fi
    else
        echo "Status:      NOT RUNNING"
    fi
}

show_help() {
    cat <<EOF
hermes-wiki-serve.sh — Hermes Wiki via obsidian-web-viewer + Tailscale

Dieses Skript wrapper't DanielCheer/obsidian-web-viewer (3D-Graph, File-Tree,
WikiLink-Navigation, Volltext-Suche, Catppuccin-Theme) und integriert Tailscale
serve für Tailnet-Zugriff.

Verwendung:
  $0 start      # Server starten (klont obv beim ersten Mal)
  $0 stop       # Server stoppen
  $0 restart    # stop + start
  $0 status     # Process-Status, Health-Check, Tailscale-URL
  $0 logs       # tail -f der Log-Files
  $0 install    # nur das Clonen/Update, kein Server-Start
  $0 --help

Umgebungsvariablen:
  HERMES_WIKI_PORT=8765
  HERMES_WIKI_DIR=/home/admin/my-karpathy-wiki
  HERMES_WIKI_LOG_DIR=\$HOME/.local/share/hermes-wiki/log
  HERMES_WIKI_TS=auto            auto|yes|no
  HERMES_WIKI_TS_PATH=/wiki      URL-Pfad unter dem Tailscale
  HERMES_WIKI_OWV_DIR=\$HOME/.local/share/hermes-wiki/owv

Dependencies (einmalig):
  - python3 (stdlib)
  - git
  - pip install PyYAML  (optional, für sauberes Frontmatter)
  - tailscale  (für Tailnet-Zugriff)

Zugriff:
  - Lokal:   http://127.0.0.1:8765/
  - Tailnet: https://<hostname>.<tailnet>.ts.net/wiki/
  - API:     http://127.0.0.1:8765/api/vault/{tree,graph,search,file/<path>}

EOF
}

# ---------------------------------------------------------------------------
# Main
# ---------------------------------------------------------------------------
case "${1:-}" in
    start)   start_server ;;
    stop)    stop_server ;;
    restart) stop_server; start_server ;;
    status)  show_status ;;
    logs)    tail -f "$HERMES_WIKI_LOG_DIR"/*.log 2>/dev/null || die "Keine Logs gefunden" ;;
    install) ensure_dirs; require_tools; install_repo ;;
    --help|-h|help|"") show_help ;;
    *)       die "Unbekanntes Kommando: $1 (--help für Hilfe)" ;;
esac