from typing import List, Optional, TypedDict, Literal, Dict, Any
from pydantic import BaseModel, Field
from langchain_core.messages import BaseMessage


# ── LLM Structured Output Models ──────────────────────────────────────────────

class EvaluationOutput(BaseModel):
    """Structured output from the reasoning analyst."""
    problem_topic: str
    identified_gap: str
    gap_magnitude: int = Field(
        ...,
        description="0-10 scale where 0 is correct/optimal and 10 is completely wrong/missing.",
        ge=0,
        le=10,
    )
    reasoning: str
    # Explain-why-wrong fields
    mistake: Optional[str] = Field(
        None, description="The specific mistake the user made (e.g., 'Used O(N²) nested loop')."
    )
    why_wrong: Optional[str] = Field(
        None, description="Why this approach fails (e.g., 'This exceeds time limit for N=10^5')."
    )
    correct_thinking: Optional[str] = Field(
        None,
        description="The correct direction to think (e.g., 'Consider a hashmap for O(1) lookup').",
    )


class HintOutput(BaseModel):
    """Structured output for the hint generator."""
    hint: str
    type: str = Field(description="e.g., Conceptual, Approach, Data Structure, Code")
    escalation_level: int = Field(
        1,
        description="1=Conceptual, 2=Approach, 3=Pseudocode, 4=Code snippet",
        ge=1,
        le=4,
    )


class SolutionOutput(BaseModel):
    """Structured output for the solution revealer."""
    solution_code: str
    explanation: str
    complexity_analysis: str


# ── Agent State ────────────────────────────────────────────────────────────────

class AgentState(TypedDict):
    """The state of the agent's graph — shared memory between all nodes."""

    # ── User Input ──
    problem: str
    user_thought: str
    code: Optional[str]
    strictness: Literal["Strict", "Moderate", "Lenient"]
    request_mode: Literal["analyze", "hint", "solution", "hint_forced"]
    session_id: str                     # Identifies the user for persistent memory

    # ── Internal Processing ──
    problem_topic: Optional[str]
    identified_gap: Optional[str]
    gap_magnitude: int
    current_hint_level: int             # 1=Conceptual, 2=Approach, 3=Pseudocode, 4=Code
    turn_count: int                     # Loop protection counter

    # ── Code Evaluation ──
    test_pass_rate: Optional[float]     # 0.0–1.0 from sandbox runner

    # ── Explain-Why-Wrong ──
    mistake: Optional[str]
    why_wrong: Optional[str]
    correct_thinking: Optional[str]

    # ── Output to User ──
    messages: List[BaseMessage]
    final_response: Optional[Dict[str, Any]]


# ── User Memory Profile ────────────────────────────────────────────────────────

class UserProfile(BaseModel):
    """Persistent learning profile for a session."""
    session_id: str
    weak_topics: Dict[str, int] = Field(
        default_factory=dict,
        description="Maps DSA topic → cumulative weakness score.",
    )
    solved_problems: int = 0
    total_turns: int = 0
    avg_gap: float = 0.0