import os
import zipfile
import tempfile
import google.generativeai as genai
from dotenv import load_dotenv
from doc_generator import generate_requirements_txt

load_dotenv()
genai.configure(api_key=os.getenv("GOOGLE_API_KEY"))
model = genai.GenerativeModel("models/gemini-2.0-flash")

ANNOTATIONS = {
    "app.py": "← Gradio + MCP server",
    "README.md": "← With demo + tag \"mcp-server-track\"",
    "demo_video.mp4": "← Link embedded in README"
}

PROMPT = """You are an expert software project documentation assistant.

You will write a clear, complete, and well-structured `README.md` file for a source code repository with the following files and content excerpts:

{file_summaries}

The README must contain:
1. A title
2. A short project description
3. An "Installation" section
4. A "Usage" section
5. A "Features" section
6. An "Authors" section (write "To be completed" if not detected)
7. A "License" section (write "To be completed" if not detected)

Respond only with the README.md content, without markdown ``` tags.
"""

def summarize_files(dir_path, max_files=20, max_chars=5000):
    summaries = []
    for root, _, files in os.walk(dir_path):
        for file in files:
            if file.endswith((".py", ".js", ".ts", ".java", ".md", ".json", ".txt")):
                try:
                    with open(os.path.join(root, file), "r", encoding="utf-8") as f:
                        content = f.read()
                    rel_path = os.path.relpath(os.path.join(root, file), dir_path)
                    summaries.append(f"### {rel_path}\n```\n{content[:1000]}\n```")
                    if len("".join(summaries)) > max_chars:
                        break
                except Exception:
                    continue
            if len(summaries) >= max_files:
                break
    return "\n\n".join(summaries)

def generate_readme_from_zip(zip_file_path: str, output_dir: str) -> (str, str):
    with tempfile.TemporaryDirectory() as tempdir:
        with zipfile.ZipFile(zip_file_path, "r") as zip_ref:
            zip_ref.extractall(tempdir)

        file_summaries = summarize_files(tempdir)
        prompt = PROMPT.format(file_summaries=file_summaries)
        response = model.generate_content(prompt)
        readme_content = response.text.strip()

        readme_path = os.path.join(output_dir, "README.md")
        index_path = os.path.join(output_dir, "index.md")
        os.makedirs(output_dir, exist_ok=True)
        # Clean markdown code blocks if they exist
        lines = readme_content.splitlines()
        if len(lines) > 2:
            lines = lines[1:-1]  # remove the first and last lines
            readme_content = "\n".join(lines)
        else:
            # if less than 3 lines, empty or keep as needed
            readme_content = ""

        with open(readme_path, "w", encoding="utf-8") as f:
            f.write(readme_content)

        # ✅ Generate index from tempdir (correct location of extracted files)
        write_index_file(tempdir, index_path)

        return readme_path, index_path

def generate_tree_structure(path: str, prefix: str = "") -> str:
    entries = sorted(os.listdir(path))
    lines = []
    dir_name = os.path.basename(os.path.abspath(path))
    lines.append(f"📁 repo/")

    for idx, entry in enumerate(entries):
        full_path = os.path.join(path, entry)
        connector = "├── "
        comment = f" {ANNOTATIONS.get(entry, '')}".rstrip()

        lines.append(prefix + connector + (entry + "/" if os.path.isdir(full_path) else entry) + comment)

        if os.path.isdir(full_path):
            extension_prefix = "│   "
            subtree = generate_tree_structure(full_path, prefix + extension_prefix)
            lines.extend(subtree.splitlines()[1:])  # skip repeated dir name

    lines.extend(["├── README.md",
                  "└── index.md"])

    return "\n".join(lines)


def write_index_file(project_path: str, output_path: str):
    structure = generate_tree_structure(project_path)
    with open(output_path, "w", encoding="utf-8") as f:
        f.write(structure)