"""
FastAPI application exposing the CodeReviewEnv via HTTP.

Endpoints:
  POST /reset         — reset environment, get initial observation
  POST /step          — submit an action, get observation + reward
  GET  /state         — get current environment state
  GET  /tasks         — list all tasks with action schema
  POST /grader        — score a completed episode
  POST /baseline      — run baseline inference and return scores
"""

from fastapi import FastAPI, HTTPException
from fastapi.middleware.cors import CORSMiddleware
from fastapi.responses import HTMLResponse
from pydantic import BaseModel
from typing import Any, Dict, Optional
import os
import inference
from models import (
    Action,
    Observation,
    EnvironmentState,
    TaskInfo,
    GraderInput,
    GraderOutput,
)
from environment import CodeReviewEnv
from graders import grade_episode
from tasks import get_all_tasks
from free_review import review_free_code
from curriculum import curriculum_tracker
from fix_verifier import verify_all_fixes
# ── App setup ─────────────────────────────────────────────────────────────
app = FastAPI(
    title="CodeReviewEnv",
    description=(
        "An OpenEnv-compliant environment for training and evaluating AI agents "
        "on real-world code review tasks. Agents receive code diffs and must "
        "identify bugs, security issues, and quality problems."
    ),
    version="1.0.0",
)

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

# Single shared environment instance (stateful per session)
env = CodeReviewEnv()


# ── Request / Response schemas ────────────────────────────────────────────

# FIX 1: task_id is fully optional — works with empty POST body too
class ResetRequest(BaseModel):
    task_id: Optional[str] = "easy"

    model_config = {"extra": "allow"}

class BaselineRequest(BaseModel):
    task_id: Optional[str] = None

class CurriculumUpdateRequest(BaseModel):
    task_id: str
    score: float

class FixRequest(BaseModel):
    task_id: str
    fixes: list
    original_code: Optional[str] = ""


class StepResponse(BaseModel):
    observation: Observation
    reward: float
    done: bool
    info: Dict[str, Any]


class BaselineScore(BaseModel):
    task_id: str
    task_name: str
    difficulty: str
    score: float
    feedback: str


class BaselineResponse(BaseModel):
    scores: list[BaselineScore]
    model_used: str
    note: str


# ── Endpoints ─────────────────────────────────────────────────────────────

@app.get("/health", tags=["Health"])
def health():
    return {
        "status": "ok",
        "environment": "CodeReviewEnv",
        "version": "1.0.0",
        "endpoints": ["/reset", "/step", "/state", "/tasks", "/grader", "/baseline"],
    }

@app.get("/", response_class=HTMLResponse, tags=["UI"])
def root():
    """Serve the web dashboard UI"""
    html_path = os.path.join(os.path.dirname(__file__), "dashboard.html")
    with open(html_path, "r", encoding="utf-8") as f:
        return f.read()


# FIX 2: Accept completely empty body by making request optional
@app.post("/reset", response_model=Observation, tags=["OpenEnv"])
def reset(request: Optional[ResetRequest] = None):
    """Reset the environment to a clean state. Returns the initial observation."""
    try:
        task_id = request.task_id if request else "easy"
        obs = env.reset(task_id=task_id)
        return obs
    except ValueError as e:
        raise HTTPException(status_code=400, detail=str(e))


@app.post("/step", response_model=StepResponse, tags=["OpenEnv"])
def step(action: Action):
    """
    Submit an action to the environment.
    Returns the next observation, reward, done flag, and info dict.
    """
    try:
        obs, reward, done, info = env.step(action)
        return StepResponse(observation=obs, reward=reward, done=done, info=info)
    except RuntimeError as e:
        raise HTTPException(status_code=400, detail=str(e))


@app.get("/state", response_model=EnvironmentState, tags=["OpenEnv"])
def state():
    """Return the full current internal state of the environment."""
    return env.state()


@app.get("/tasks", tags=["OpenEnv"])
def tasks():
    """
    Return all available tasks with their action schema.
    Used by agents to discover what tasks exist and what actions are valid.
    """
    action_schema = {
        "type": "object",
        "required": ["verdict"],
        "properties": {
            "comments": {
                "type": "array",
                "description": "List of code review comments",
                "items": {
                    "type": "object",
                    "required": ["line_number", "issue_type", "severity", "description"],
                    "properties": {
                        "line_number": {"type": "integer", "description": "Line number (1-indexed)"},
                        "issue_type": {
                            "type": "string",
                            "enum": ["bug", "security", "performance", "style", "logic"],
                        },
                        "severity": {
                            "type": "string",
                            "enum": ["critical", "major", "minor"],
                        },
                        "description": {"type": "string", "description": "Issue description"},
                        "suggested_fix": {"type": "string", "description": "Optional fix suggestion"},
                    },
                },
            },
            "verdict": {
                "type": "string",
                "enum": ["approve", "request_changes", "comment"],
                "description": "Final review verdict",
            },
            "summary": {
                "type": "string",
                "description": "Optional overall review summary",
            },
        },
    }

    result = []
    for t in get_all_tasks():
        result.append(
            {
                "id": t["id"],
                "name": t["name"],
                "description": t["description"],
                "difficulty": t["difficulty"],
                "max_steps": t["max_steps"],
                "pr_title": t["pr_title"],
                "file_name": t["file_name"],
                "action_schema": action_schema,
            }
        )
    return {"tasks": result, "action_schema": action_schema}


@app.post("/grader", response_model=GraderOutput, tags=["OpenEnv"])
def grader(grader_input: GraderInput):
    """
    Score a completed episode. Returns deterministic score between 0.0-1.0.
    Accepts episode history produced by /step calls.
    """
    try:
        result = grade_episode(grader_input)
        return result
    except Exception as e:
        raise HTTPException(status_code=400, detail=str(e))


# FIX 3: runs inference explicitly in-process to capture AI findings
@app.post("/baseline", tags=["OpenEnv"])
def baseline(request: Optional[BaselineRequest] = None):

    task_id = request.task_id if request and request.task_id else "easy"

    providers = inference.get_providers(inference.MODEL_NAME)

    # Hook into parse_llm_response to capture the action
    captured = {}
    original_parse = inference.parse_llm_response

    def hooked_parse(content):
        action = original_parse(content)
        captured['action'] = action
        return action

    inference.parse_llm_response = hooked_parse

    try:
        res = inference.run_task(task_id, providers, verbose=False)

        action = captured.get('action')
        ai_findings = [c.model_dump() for c in action.comments] if action else []
        verdict = action.verdict if action else "comment"

        return {
            "scores": [res],
            "model_used": providers[0]['model'] if providers else inference.MODEL_NAME,
            "note": "Temperature=0.",
            "ai_findings": ai_findings,
            "verdict": verdict
        }
    except Exception as e:
        raise HTTPException(status_code=500, detail=str(e))
    finally:
        inference.parse_llm_response = original_parse


# ── Free Review Route ───────────────────────────────────────────────────

class FreeReviewRequest(BaseModel):
    code: str
    language: Optional[str] = "python"
    context: Optional[str] = ""

class FreeReviewResponse(BaseModel):
    issues: list
    overall_verdict: str
    summary: str
    positive_aspects: list
    total_issues: int
    critical_count: int
    major_count: int
    minor_count: int
    error: Optional[str] = None

@app.post("/review/free", tags=["Free Review"])
def free_review(request: FreeReviewRequest):
    """
    Review any arbitrary code using AI.
    No grading — works on any code, any language.
    Perfect for ad-hoc reviews and demos.
    """
    result = review_free_code(
        code=request.code,
        language=request.language,
        context=request.context
    )
    
    if "error" in result:
        return FreeReviewResponse(
            issues=[],
            overall_verdict="error",
            summary=result["error"],
            positive_aspects=[],
            total_issues=0,
            critical_count=0,
            major_count=0,
            minor_count=0,
            error=result["error"]
        )
    
    issues = result.get("issues", [])
    return FreeReviewResponse(
        issues=issues,
        overall_verdict=result.get("overall_verdict", "comment"),
        summary=result.get("summary", ""),
        positive_aspects=result.get("positive_aspects", []),
        total_issues=len(issues),
        critical_count=sum(1 for i in issues 
                          if i.get("severity") == "critical"),
        major_count=sum(1 for i in issues 
                       if i.get("severity") == "major"),
        minor_count=sum(1 for i in issues 
                       if i.get("severity") == "minor"),
        error=None
    )


# ── Debug Route ─────────────────────────────────────────────────────────

@app.post("/debug-baseline", tags=["Debug"])
def debug_baseline():
    import inference
    from openai import OpenAI

    client = OpenAI(
        api_key=inference._api_key,
        base_url=inference.API_BASE_URL,
    )

    env = CodeReviewEnv()
    obs = env.reset(task_id="easy")

    try:
        response = client.chat.completions.create(
            model=inference.MODEL_NAME,
            messages=[
                {"role": "system", "content": inference.SYSTEM_PROMPT},
                {"role": "user", "content": inference.build_user_prompt(obs.model_dump())},
            ],
            temperature=0.0,
            max_tokens=2000,
        )
        raw = response.choices[0].message.content
        return {"raw_response": raw}
    except Exception as e:
        return {"error": str(e)}

# ── Dashboard UI ─────────────────────────────────────────────────────────

@app.get("/dashboard", response_class=HTMLResponse, tags=["UI"])
def dashboard():
    """Serve the web dashboard UI"""
    html_path = os.path.join(os.path.dirname(__file__), "dashboard.html")
    with open(html_path, "r", encoding="utf-8") as f:
        return f.read()


# ── Curriculum Endpoints ──────────────────────────────

@app.post("/curriculum/update", tags=["Curriculum"])
def curriculum_update(request: CurriculumUpdateRequest):
    """
    Record agent score for a task.
    Returns recommended next task based on performance.
    When agent averages above threshold for 3 episodes,
    it gets promoted to the next harder task automatically.
    """
    result = curriculum_tracker.update(
        task_id=request.task_id,
        score=request.score,
    )
    return result


@app.get("/curriculum/state", tags=["Curriculum"])
def curriculum_state():
    """
    Show full curriculum progress across all tasks.
    Shows mastered tasks, current level, promotions log.
    """
    return curriculum_tracker.get_state()


@app.post("/curriculum/reset", tags=["Curriculum"])
def curriculum_reset():
    """Reset curriculum — start agent from scratch."""
    curriculum_tracker.reset()
    return {"message": "Curriculum reset. Agent starts from easy."}


# ── Bug Fix Endpoints ─────────────────────────────────

@app.post("/fix", tags=["Bug Fixing"])
def submit_fix(request: FixRequest):
    """
    Agent submits fixes for bugs it found.
    Verifier checks each fix against known issues.
    Returns fix reward — bonus on top of review reward.

    fixes format:
    [
        {
            "line_number": 5,
            "issue_description": "ZeroDivisionError...",
            "fixed_code": "return total / len(numbers) if numbers else 0"
        }
    ]
    """
    from tasks import get_task

    task = get_task(request.task_id)
    if not task:
        raise HTTPException(
            status_code=400,
            detail=f"Unknown task_id: {request.task_id}"
        )

    known_issues  = task["known_issues"]
    original_code = request.original_code or task["diff"]

    result = verify_all_fixes(
        original_code=original_code,
        agent_fixes=request.fixes,
        known_issues=known_issues,
    )

    return {
        "task_id":         request.task_id,
        "fix_reward":      result["total_fix_reward"],
        "fixes_correct":   result["fixes_correct"],
        "fixes_partial":   result["fixes_partial"],
        "fixes_wrong":     result["fixes_wrong"],
        "fixes_missing":   result["fixes_missing"],
        "breakdown":       result["breakdown"],
        "message":         result["message"],
    }


@app.get("/fix/schema", tags=["Bug Fixing"])
def fix_schema():
    """Return the schema for submitting fixes."""
    return {
        "endpoint": "POST /fix",
        "description": "Submit bug fixes after reviewing code",
        "request_format": {
            "task_id": "string — same task_id used in /reset",
            "fixes": [
                {
                    "line_number": "integer — line where bug was found",
                    "issue_description": "string — what the bug is",
                    "fixed_code": "string — your corrected version of that line",
                }
            ],
            "original_code": "string — optional, original code for comparison",
        },
        "reward_values": {
            "correct_fix_critical": "+0.40",
            "correct_fix_major":    "+0.35",
            "correct_fix_minor":    "+0.30",
            "partial_fix":          "+0.10",
            "wrong_fix":            "-0.10",
            "missing_critical_fix": "-0.05 per issue",
        },
    }

# ── Entry point ───────────────────────────────────────────────────────────

if __name__ == "__main__":
    import uvicorn
    uvicorn.run("app:app", host="0.0.0.0", port=7860, reload=False)