from io import StringIO
import numpy as np
import pandas as pd
import requests
from bs4 import BeautifulSoup
import json
import os
import pymupdf as fitz
import uuid
import zipfile
import io
import subprocess
import os
import re
import time
from datetime import datetime
from dotenv import load_dotenv
import warnings
from fastapi import FastAPI, HTTPException
from fastapi.middleware.cors import CORSMiddleware
from fastapi.responses import FileResponse
from fastapi.staticfiles import StaticFiles
from pydantic import BaseModel
from typing import Any, Dict, List, Literal, Optional

load_dotenv()

warnings.filterwarnings("ignore")

app = FastAPI(title="3GPP Document Finder API", 
              description="API to find 3GPP documents based on TSG document IDs")

app.mount("/static", StaticFiles(directory="static"), name="static")

origins = [
    "*",
]

app.add_middleware(
    CORSMiddleware,
    allow_origins=origins,
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

def get_pdf_bytes(specification: str, version: str):
    doc_id = specification
    series = doc_id.split(".")[0]
    response = requests.get(f"https://www.3gpp.org/ftp/Specs/archive/{series}_series/{doc_id}/{doc_id.replace('.', '')}-{version}.zip", verify=False)
    if response.status_code != 200:
        raise Exception("Téléchargement du ZIP échoué")

    zip_bytes = io.BytesIO(response.content)

    with zipfile.ZipFile(zip_bytes) as zf:
        for file_name in zf.namelist():
            if file_name.endswith("doc") or file_name.endswith("docx"):
                ext = file_name.split(".")[-1]
                doc_bytes = zf.read(file_name)
                temp_id = str(uuid.uuid4())
                input_path = f"/tmp/{temp_id}.{ext}"
                output_path = f"/tmp/{temp_id}.pdf"

                with open(input_path, "wb") as f:
                    f.write(doc_bytes)
                
                subprocess.run([
                    "libreoffice",
                    "--headless",
                    "--convert-to", "pdf",
                    "--outdir", "/tmp",
                    input_path
                ], check=True)

                with open(output_path, "rb") as f:
                    pdf_data = f.read()
                
                os.remove(input_path)
                os.remove(output_path)

                return io.BytesIO(pdf_data)
        raise Exception("Aucun fichier .doc/.docx trouvé dans le ZIP")

def get_scope(specification: str, version: str):
    pdf_bytes = get_pdf_bytes(specification, version)
    doc = fitz.open(stream=pdf_bytes, filetype="pdf")

    for content in doc.get_toc():
        if "scope" in content[1].lower():
            page_num = content[2] - 1
            break

    doc = doc[page_num:]

    pdf_full_text = " ".join(page.get_text("text") for page in doc)
    pdf_postprocess_text = re.sub(r"\s+", " ", pdf_full_text)
    pdf_postprocess_text = pdf_postprocess_text.replace("1 Scope", " !-! ")
    pdf_postprocess_text = pdf_postprocess_text.replace("2 Reference", " !-! ")
    pdf_postprocess_text = pdf_postprocess_text.replace("", "- ")

    return pdf_postprocess_text.split(" !-! ")[1]

class DocRequest(BaseModel):
    doc_id: str
    release: Optional[int] = None

class DocResponse(BaseModel):
    doc_id: str
    url: str
    scope: Optional[str] = None
    search_time: float

class BatchDocRequest(BaseModel):
    doc_ids: List[str]
    release: Optional[int] = None

class BatchDocResponse(BaseModel):
    results: Dict[str, str]
    missing: List[str]
    search_time: float

class KeywordRequest(BaseModel):
    keywords: str
    release: Optional[str] = None
    wg: Optional[str] = None
    spec_type: Optional[Literal["TS", "TR"]] = None
    mode: Optional[Literal["and", "or"]] = "and"

class KeywordResponse(BaseModel):
    results: List[Dict[str, str]]
    search_time: float

class TsgDocFinder:
    def __init__(self):
        self.main_ftp_url = "https://www.3gpp.org/ftp"
        self.indexer_file = "indexed_docs.json"
        self.indexer, self.last_indexer_date = self.load_indexer()

    def load_indexer(self):
        """Load existing index if available"""
        if os.path.exists(self.indexer_file):
            with open(self.indexer_file, "r", encoding="utf-8") as f:
                x = json.load(f)
                return x["docs"], x["last_indexed_date"]
        return {}, None
    
    def save_indexer(self):
        """Save the updated index"""
        with open(self.indexer_file, "w", encoding="utf-8") as f:
            today = datetime.today()
            output = {"docs": self.indexer, "last_indexed_date": today.strftime("%d/%m/%Y-%H:%M:%S")}
            json.dump(output, f, indent=4, ensure_ascii=False)
    
    def get_workgroup(self, doc):
        main_tsg = "tsg_ct" if doc[0] == "C" else "tsg_sa" if doc[0] == "S" else None
        if main_tsg is None:
            return None, None, None
        workgroup = f"WG{int(doc[1])}" if doc[1].isnumeric() else main_tsg.upper()
        return main_tsg, workgroup, doc
    
    def find_workgroup_url(self, main_tsg, workgroup):
        """Find the URL for the specific workgroup"""
        response = requests.get(f"{self.main_ftp_url}/{main_tsg}", verify=False)
        soup = BeautifulSoup(response.text, 'html.parser')
        
        for item in soup.find_all("tr"):
            link = item.find("a")
            if link and workgroup in link.get_text():
                return f"{self.main_ftp_url}/{main_tsg}/{link.get_text()}"
                
        return f"{self.main_ftp_url}/{main_tsg}/{workgroup}"

    def get_docs_from_url(self, url):
        """Get list of documents/directories from a URL"""
        try:
            response = requests.get(url, verify=False, timeout=10)
            soup = BeautifulSoup(response.text, "html.parser")
            return [item.get_text() for item in soup.select("tr td a")]
        except Exception as e:
            print(f"Error accessing {url}: {e}")
            return []
    
    def search_document(self, doc_id: str, release = None):
        """Search for a specific document by its ID"""
        original_id = doc_id
        
        # Check if already indexed
        if original_id in self.indexer:
            return self.indexer[original_id]
        
        for doc in self.indexer:
            if doc.startswith(original_id):
                return self.indexer[doc]
        
        # Parse the document ID
        main_tsg, workgroup, doc = self.get_workgroup(doc_id)
        if not main_tsg:
            return f"Could not parse document ID: {doc_id}"
        
        print(f"Searching for {original_id} (parsed as {doc}) in {main_tsg}/{workgroup}...")
        
        # Find the workgroup URL
        wg_url = self.find_workgroup_url(main_tsg, workgroup)
        if not wg_url:
            return f"Could not find workgroup for {doc_id}"
        
        # Search in the workgroup directories
        meeting_folders = self.get_docs_from_url(wg_url)
        
        for folder in meeting_folders:
            meeting_url = f"{wg_url}/{folder}"
            meeting_contents = self.get_docs_from_url(meeting_url)
            key = "docs" if "docs" in [x.lower() for x in meeting_contents] else "tdocs" if "tdocs" in [x.lower() for x in meeting_contents] else None
            if key is not None:
                docs_url = f"{meeting_url}/{key}"
                print(f"Checking {docs_url}...")
                files = self.get_docs_from_url(docs_url)
                
                # Check for the document in the main Docs folder
                for file in files:
                    if doc in file.lower() or original_id in file:
                        doc_url = f"{docs_url}/{file}"
                        self.indexer[original_id] = doc_url
                        return doc_url
                
                # Check in ZIP subfolder if it exists
                if "zip" in [x for x in files]:
                    zip_url = f"{docs_url}/zip"
                    print(f"Checking {zip_url}...")
                    zip_files = self.get_docs_from_url(zip_url)
                    
                    for file in zip_files:
                        if doc in file.lower() or original_id in file:
                            doc_url = f"{zip_url}/{file}"
                            self.indexer[original_id] = doc_url
                            self.save_indexer()
                            return doc_url
        
        return f"Document {doc_id} not found"
    

class SpecDocFinder:
    def __init__(self):
        self.chars = "0123456789abcdefghijklmnopqrstuvwxyz"
        
    def search_document(self, doc_id, release = None):
        series = doc_id.split(".")[0]
        while len(series) < 2:
            series = "0" + series
        
        url = f"https://www.3gpp.org/ftp/Specs/archive/{series}_series/{doc_id}"

        response = requests.get(url, verify=False)
        soup = BeautifulSoup(response.text, 'html.parser')
        items = soup.find_all("tr")[1:]
        version_found = None
        if release is None:
            try:
                item = items[-1].find("a")
            except Exception as e:
                print(e)
                return f"Unable to find specification {doc_id}"
            a, b, c = [_ for _ in item.get_text().split("-")[-1].replace(".zip", "")]
            version = f"{self.chars.index(a)}.{self.chars.index(b)}.{self.chars.index(c)}"
            version_found = (version, item.get("href"))
            _, spec_url = version_found
            return spec_url if version_found is not None else f"Specification {doc_id} not found"
        else:
            for item in items:
                x = item.find("a")
                if f"{doc_id.replace('.', '')}-{self.chars[int(release)]}" in x.get_text():
                    a, b, c = [_ for _ in x.get_text().split("-")[-1].replace(".zip", "")]
                    version = f"{self.chars.index(a)}.{self.chars.index(b)}.{self.chars.index(c)}"
                    version_found = (version, x.get("href"))
            _, spec_url = version_found
            return spec_url if version_found is not None else f"Specification {doc_id} not found"

finder_tsg = TsgDocFinder()
finder_spec = SpecDocFinder()

@app.get("/")
async def main_menu():
    return FileResponse(os.path.join("templates", "index.html"))

@app.post("/search-spec", response_model=KeywordResponse)
def search_spec(request: KeywordRequest):
    chars = "0123456789abcdefghijklmnopqrstuvwxyz"
    start_time = time.time()
    response = requests.get(f'https://www.3gpp.org/dynareport?code=status-report.htm', headers={"User-Agent": 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.124 Safari/537.36'}, verify=False)
    dfs = pd.read_html(StringIO(response.text), storage_options={'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.124 Safari/537.36'}, encoding="utf-8")

    for x in range(len(dfs)):
        dfs[x] = dfs[x].replace({np.nan: None})

    columns_needed = [0, 1, 2, 3, 4]
    extracted_dfs: List[pd.DataFrame] = [df.iloc[:, columns_needed] for df in dfs]
    columns = [x.replace("\xa0", "_") for x in extracted_dfs[0].columns]

    specifications = []

    for df in extracted_dfs:
        for index, row in df.iterrows():
            doc = row.to_list()
            doc_dict = dict(zip(columns, doc))
            specifications.append(doc_dict)
    
    kws = [_.lower() for _ in request.keywords.split(" ")]
    results = []

    for spec in specifications:
        if request.mode == "and":
            if not all(kw in spec["title"].lower() for kw in kws):
                continue
        elif request.mode == "or":
            if not any(kw in spec["title"].lower() for kw in kws):
                continue
        release = request.release
        working_group = request.wg
        spec_type = request.spec_type

        if spec.get('vers', None) is None or (release is not None and spec["vers"].split(".")[0] != str(release)):
            continue
        if spec.get('WG', None) is None or (working_group is not None and spec["WG"] != working_group):
            continue
        if spec_type is not None and spec["type"] != spec_type:
            continue
        
        doc_id = str(spec["spec_num"])
        series = doc_id.split(".")[0]
        a, b, c = str(spec["vers"]).split(".")
        print(spec["vers"])
        if not (int(a) > 35 or int(b) > 35 or int(c) > 35): 
            spec_url = f"https://www.3gpp.org/ftp/Specs/archive/{series}_series/{doc_id}/{doc_id.replace('.', '')}-{chars[int(a)]}{chars[int(b)]}{chars[int(c)]}.zip"
        else:
            x,y,z = str(a), str(b), str(c)
            while len(x) < 2:
                x = "0" + x
            while len(y) < 2:
                y = "0" + y
            while len(z) < 2:
                z = "0" + z
            spec_url = f"https://www.3gpp.org/ftp/Specs/archive/{series}_series/{doc_id}/{doc_id.replace('.', '')}-{x}{y}{z}.zip"
        results.append({
            "id": str(spec["spec_num"]),
            "title": spec["title"],
            "type": "Technical Specification" if spec["type"] == "TS" else "Technical Report",
            "release": str(spec["vers"].split(".")[0]),
            "version": str(spec["vers"]),
            "working_group": spec["WG"],
            "url": spec_url
        })

    if len(results) > 0:
        return KeywordResponse(
            results=results,
            search_time=time.time() - start_time
        )
    else:
        raise HTTPException(status_code=404, detail="Specification not found")
    
@app.post("/find", response_model=DocResponse)
def find_document(request: DocRequest):
    start_time = time.time()
    finder = finder_tsg if request.doc_id[0].isalpha() else finder_spec
    print(finder)
    
    result = finder.search_document(request.doc_id, request.release)

    if "not found" not in result and "Could not" not in result and "Unable" not in result:
        version = result.split("/")[-1].replace(".zip", "").split("-")[-1]
        return DocResponse(
            doc_id=request.doc_id,
            url=result,
            search_time=time.time() - start_time
        ) if isinstance(finder, TsgDocFinder) else DocResponse(
            doc_id=request.doc_id,
            url=result,
            search_time=time.time() - start_time,
            scope=get_scope(request.doc_id, version)
        )
    else:
        raise HTTPException(status_code=404, detail=result)

@app.post("/batch", response_model=BatchDocResponse)
def find_documents_batch(request: BatchDocRequest):
    start_time = time.time()
    
    results = {}
    missing = []
    
    for doc_id in request.doc_ids:
        finder = finder_tsg if doc_id[0].isalpha() else finder_spec
        result = finder.search_document(doc_id)
        if "not found" not in result and "Could not" not in result and "Unable" not in result:
            results[doc_id] = result
        else:
            missing.append(doc_id)
    
    return BatchDocResponse(
        results=results,
        missing=missing,
        search_time=time.time() - start_time
    )