"""Praxis scenario schema — YAML DSL → Pydantic (D-018, D-009, D-010).

Defines the typed model for a branching role-play scenario. Loaded from YAML
by server/scenarios/loader.py. Drives Pipecat Flows (TASK-03-03).

Per RESEARCH.md example + PROJECT.md D-010: one branch point (escalate vs
accept), failure_mode field present (D-009 — not provoked in v0.1).
"""

from __future__ import annotations

import re
from typing import Literal

from pydantic import BaseModel, Field, ValidationError, field_validator

_SEMVER_RE = re.compile(r"^\d+\.\d+\.\d+(?:-[0-9A-Za-z.-]+)?(?:\+[0-9A-Za-z.-]+)?$")


class ScenarioPersona(BaseModel):
    """The AI character's voice + identity (D-006 — one voice for role-play + mentor)."""

    voice_id: str = Field(..., description="TTS voice id (Cartesia/Piper) — same as mentor per D-006")
    character: str = Field(..., description="Character name + role, e.g. 'Customer (Jordan)'")


class ScenarioSetup(BaseModel):
    """The system prompt + opening line that start the role-play."""

    system_prompt: str = Field(..., description="LLM system prompt (stays in character)")
    opening_line: str = Field(..., description="First TTS utterance the AI speaks")


class BranchTrigger(BaseModel):
    """Learner signals that trigger a branch transition (R7 classification)."""

    learner_signals: list[str] = Field(
        ..., description="Signals the branch classifier looks for (e.g. 'empathy', 'defensive')"
    )


class Branch(BaseModel):
    """One branch outcome (D-010 — v0.1 has two: accept_resolution + escalate)."""

    id: str = Field(..., description="Branch id, e.g. 'accept_resolution' / 'escalate'")
    trigger: BranchTrigger
    outcome: Literal["success", "failure"] = Field(..., description="Branch outcome label")
    failure_mode: str | None = Field(
        None, description="D-009 failure_mode (present, not provoked in v0.1)"
    )
    debrief_focus: str = Field(..., description="What the debrief emphasizes for this branch")


class ScenarioDebrief(BaseModel):
    """Debrief generation config (D-020 — deepseek-v4-flash:cloud, no-think)."""

    model: str = Field("deepseek-v4-flash:cloud", description="Ollama model for the debrief")
    mode: Literal["no_think", "think", "max_think"] = Field(
        "no_think", description="Reasoning mode (no_think for latency, D-020)"
    )
    prompt_template: str = Field(
        "debrief/default", description="Prompt template id (resolved by server/debrief.py)"
    )


class RubricMapping(BaseModel):
    """Maps a scenario to one rubric criterion (SLICE-02 — D-039).

    A scenario lists the rubric criteria it exercises; the scoring engine
    (SLICE-03) extracts evidence for each and scores against the rubric YAML.
    """

    criterion_id: str = Field(..., description="Rubric criterion id, e.g. 'empathy'")
    weight: float | None = Field(
        None, description="Optional per-scenario weight override (defaults to rubric weight)"
    )
    evidence_required: bool = Field(
        True, description="If True, the scorer must find evidence to score this criterion"
    )


class Scenario(BaseModel):
    """A Praxis role-play scenario (D-018 — YAML → Pydantic → Pipecat Flows).

    Extended in v0.3 (SLICE-02) with rubric mapping + IRT + provenance fields.
    All new fields have defaults so v0.1 scenario YAMLs still load unchanged.
    """

    id: str = Field(..., description="Scenario id, e.g. 'cs_refund_ca_v01'")
    path: str = Field(..., description="Skill path, e.g. 'customer_service'")
    market: str = Field(..., description="Market code, e.g. 'CA'")
    language: str = Field("en-CA", description="Language code")
    title: str = Field(..., description="Human-readable scenario title")
    difficulty: int = Field(1, ge=1, le=5, description="Difficulty 1-5")
    failure_mode: str = Field(
        ..., description="D-009 failure_mode — present (not provoked in v0.1)"
    )
    persona: ScenarioPersona
    setup: ScenarioSetup
    success_criteria: list[str] = Field(..., min_length=1)
    common_mistakes: list[str] = Field(..., min_length=1)
    branches: list[Branch] = Field(..., min_length=1, description="Branch points (v0.1: 2)")
    debrief: ScenarioDebrief

    rubric_criteria: list[RubricMapping] = Field(
        default_factory=list,
        description="Rubric criteria this scenario exercises (SLICE-02). Empty for v0.1 scenarios.",
    )
    irt_target_p: float = Field(
        0.7, ge=0.0, le=1.0, description="Target P for IRT scenario selection (D-035 default 0.7)"
    )
    version: str = Field("1.0.0", description="Scenario semver (D-036)")
    generated_from: str | None = Field(
        None, description="AI-variation backref: parent scenario id if this was generated (D-036)"
    )
    intent_hash: str | None = Field(
        None, description="Structural drift detection hash (D-036)"
    )

    @field_validator("version")
    @classmethod
    def _validate_semver(cls, v: str) -> str:
        if not _SEMVER_RE.match(v):
            raise ValueError(f"invalid semver: {v!r}")
        return v

    def branch_ids(self) -> list[str]:
        return [b.id for b in self.branches]

    def branch_by_id(self, branch_id: str) -> Branch | None:
        for b in self.branches:
            if b.id == branch_id:
                return b
        return None

    def rubric_criterion_ids(self) -> list[str]:
        return [m.criterion_id for m in self.rubric_criteria]


__all__ = [
    "Scenario",
    "ScenarioPersona",
    "ScenarioSetup",
    "Branch",
    "BranchTrigger",
    "ScenarioDebrief",
    "RubricMapping",
    "ValidationError",
]