import os
import markdown
from fastapi import APIRouter, Request, HTTPException, Depends
from fastapi.responses import HTMLResponse

from deps import current_user

router = APIRouter()

# Whitelist allowed files. 
# We look for them in the root directory relative to 'app' parent.
# Since app is in /app inside docker, the root volume mount is usually at /app or mapped.
# Code Tour Step 828 shows 'app/main.py' path analysis.
# If workdir is /app (docker), and files are in /app (root of repo mapped to /app), then "README.md" is at "./README.md".

ALLOWED_DOCS = {
    "README.md": "Start Guide (Readme)",
    "QUICKSTART.md": "Schnellstart",
    "HANDBUCH.md": "Benutzerhandbuch",
    "CODE_TOUR.md": "Code Tour (Dev)",
    "ARCHITECTURE_ROLES_GROUPS.md": "Architektur",
    "DIARY_RAG_README.md": "Tagebuch & RAG Info",
    "CrumbTech.md": "Technische Details",
    "QDRANT_ACCESS.md": "Vektor DB Access",
    "deploy_security_fixes.sh": "Security Script (Source)" # Maybe viewing scripts is cool too? Let's stick to MD for now.
}

@router.get("/docs", response_class=HTMLResponse)
async def list_docs(req: Request):
    """
    List available documentation files.
    """
    # Check which exist
    available = []
    
    # We use /docs_root/ inside the container (see Dockerfile)
    # Fallback to "." if running locally without container
    if os.path.exists("/docs_root"):
        base_path = "/docs_root"
    else:
        base_path = "." 
    
    for filename, title in ALLOWED_DOCS.items():
        if os.path.exists(os.path.join(base_path, filename)):
            available.append({"name": title, "file": filename})
    
    return req.app.state.render(
        req,
        "pages/docs_index.html",
        docs=available,
        page_title="Dokumentation"
    )

@router.get("/docs/{filename}", response_class=HTMLResponse)
async def view_doc(req: Request, filename: str):
    """
    Render a specific markdown file.
    """
    if filename not in ALLOWED_DOCS:
        raise HTTPException(404, "File not found or not allowed.")
        
    base_path = "."
    if os.path.exists("/docs_root"):
        base_path = "/docs_root"
        
    file_path = os.path.join(base_path, filename)
    
    if not os.path.exists(file_path):
        raise HTTPException(404, "File not on server.")
        
    try:
        with open(file_path, "r", encoding="utf-8") as f:
            content = f.read()
            
        # Convert Markdown to HTML
        # Extensions for better rendering: tables, fenced_code
        html_content = markdown.markdown(
            content, 
            extensions=['tables', 'fenced_code', 'nl2br']
        )
        
        return req.app.state.render(
            req,
            "pages/doc_viewer.html",
            doc_title=ALLOWED_DOCS[filename],
            doc_content=html_content,
            filename=filename
        )
        
    except Exception as e:
        raise HTTPException(500, f"Error rendering document: {e}")