# agent.py
import os
from typing import Optional, List
from crewai import Agent, Task, Crew, Process
from crewai_tools import GithubSearchTool
from google import genai  # Gemini client (google-genai package)
from dotenv import load_dotenv

load_dotenv()

# ---------------------------
# CONFIG
# ---------------------------
GITHUB_TOKEN = os.getenv("GITHUB_TOKEN")
GOOGLE_API_KEY = os.getenv("GOOGLE_API_KEY")

if not GOOGLE_API_KEY:
    raise RuntimeError("❌ Missing GOOGLE_API_KEY (get one from https://aistudio.google.com)")

# Gemini Client
client = genai.Client(api_key=GOOGLE_API_KEY)
MODEL_NAME = os.getenv("GEMINI_MODEL", "gemini-1.5-flash")

DEFAULT_CONTENT_TYPES = ["code", "pr", "issue", "repo"]

# ---------------------------
# Gemini Embedding Adapter (Free Embeddings)
# ---------------------------
class GeminiEmbedding:
    """Uses Google Gemini text-embedding-004 model (free tier)"""

    def __init__(self, model="text-embedding-004", api_key=None):
        self.model = model
        self.client = genai.Client(api_key=api_key or GOOGLE_API_KEY)

    def embed_documents(self, texts: List[str]) -> List[List[float]]:
        vectors = []
        for text in texts:
            try:
                res = self.client.models.embed_content(model=self.model, contents=text)
                vectors.append(res.embedding.values)
            except Exception as e:
                print(f"⚠️ Embedding error: {e}")
                vectors.append([])
        return vectors

    def embed_query(self, text: str) -> List[float]:
        try:
            res = self.client.models.embed_content(model=self.model, contents=text)
            return res.embedding.values
        except Exception as e:
            print(f"⚠️ Embedding query error: {e}")
            return []


# ---------------------------
# Gemini LLM Wrapper
# ---------------------------
class GeminiLLM:
    def __init__(self, model: str):
        self.model = model

    def generate(self, prompt: str) -> str:
        """CrewAI-compatible LLM generate method."""
        try:
            response = client.models.generate_content(
                model=self.model,
                contents=prompt,
                generation_config={"temperature": 0.7, "max_output_tokens": 1024}
            )
            return response.text
        except Exception as e:
            return f"⚠️ Gemini API error: {e}"


# Instantiate LLM + embedder
gemini_llm = GeminiLLM(MODEL_NAME)
embedder = GeminiEmbedding(api_key=GOOGLE_API_KEY)

# ---------------------------
# GitHub Tool using free embeddings
# ---------------------------
def github_tool(repo_url: Optional[str] = None) -> GithubSearchTool:
    """Create a GitHub Search Tool with free Gemini embeddings (no OpenAI key)."""
    if not GITHUB_TOKEN:
        raise RuntimeError("Missing GITHUB_TOKEN in environment.")

    if repo_url:
        return GithubSearchTool(
            github_repo=repo_url,
            gh_token=GITHUB_TOKEN,
            content_types=DEFAULT_CONTENT_TYPES,
            embedder=embedder,
        )
    return GithubSearchTool(
        gh_token=GITHUB_TOKEN,
        content_types=DEFAULT_CONTENT_TYPES,
        embedder=embedder,
    )


# ---------------------------
# AGENTS
# ---------------------------
def make_agents(repo_url: str):
    repo_search = github_tool(repo_url)

    repo_mapper = Agent(
        role="Repository Mapper",
        goal="Map repo structure, dependencies, and frameworks.",
        backstory="Understands directory trees, tech stacks, and configuration files.",
        tools=[repo_search],
        llm=gemini_llm,
        verbose=True,
    )

    code_reviewer = Agent(
        role="Code Reviewer",
        goal="Perform code review for quality, structure, and clarity.",
        backstory="A senior engineer giving actionable review comments with examples.",
        tools=[repo_search],
        llm=gemini_llm,
        verbose=True,
    )

    security_auditor = Agent(
        role="Security Auditor",
        goal="Identify secrets, vulnerabilities, unsafe APIs, and dependencies.",
        backstory="A white-hat hacker finding issues and giving fixes.",
        tools=[repo_search],
        llm=gemini_llm,
        verbose=True,
    )

    doc_explainer = Agent(
        role="Documentation Explainer",
        goal="Summarize architecture, data flow, and how to run the project.",
        backstory="Explains tech systems simply and clearly with examples.",
        tools=[repo_search],
        llm=gemini_llm,
        verbose=True,
    )

    manager = Agent(
        role="Engineering Manager",
        goal="Coordinate all agents and compile a clear, cohesive final report.",
        backstory="Ensures a professional, well-structured final document.",
        allow_delegation=True,
        llm=gemini_llm,
        verbose=True,
    )

    return repo_mapper, code_reviewer, security_auditor, doc_explainer, manager


# ---------------------------
# TASKS
# ---------------------------
def make_tasks(repo_url: str, brief: str = ""):
    prefix = f"Target Repository: {repo_url}\nBrief: {brief}\nInclude file paths where relevant."

    t_map = Task(
        description=f"{prefix}\nMap the repository structure, dependencies, languages, and build tools.",
        expected_output="Markdown-formatted repository map with bullets and paths.",
        agent_role="Repository Mapper",
    )

    t_review = Task(
        description=f"{prefix}\nPerform detailed code review (readability, refactors, testing, etc.).",
        expected_output="Actionable review bullets grouped by issue type.",
        agent_role="Code Reviewer",
    )

    t_sec = Task(
        description=f"{prefix}\nPerform security audit (secrets, vulnerabilities, dependencies).",
        expected_output="Security findings table (Issue | Evidence | Risk | Fix).",
        agent_role="Security Auditor",
    )

    t_doc = Task(
        description=f"{prefix}\nExplain architecture, modules, data flow, setup, and usage.",
        expected_output="Readable explanation with Quickstart and architecture overview.",
        agent_role="Documentation Explainer",
    )

    t_merge = Task(
        description="Merge all outputs into a clean, single Markdown report with clear sections and TOC.",
        expected_output="Final cohesive Markdown report.",
        agent_role="Engineering Manager",
    )

    return t_map, t_review, t_sec, t_doc, t_merge


# ---------------------------
# RUNNER
# ---------------------------
def run_repo_review(repo_url: str, brief: str = "") -> str:
    repo_mapper, reviewer, auditor, explainer, manager = make_agents(repo_url)
    t_map, t_review, t_sec, t_doc, t_merge = make_tasks(repo_url, brief)

    crew = Crew(
        agents=[repo_mapper, reviewer, auditor, explainer, manager],
        tasks=[t_map, t_review, t_sec, t_doc, t_merge],
        process=Process.hierarchical,
        manager_agent=manager,
        verbose=True,
    )

    result = crew.kickoff()
    return str(result)