"""Typed configuration from .env / environment.

Loading rules (see SPEC_NEW §5):
- DATABASE_URL is required at startup — everything needs the DB.
- External-service credentials are optional at load time so DRY_RUN and tests
  work without them, but any module that actually needs one must call
  `settings.require("NAME")`, which fails loudly with the exact missing var.
"""

from __future__ import annotations

from functools import lru_cache
from pathlib import Path

from pydantic_settings import BaseSettings, SettingsConfigDict

REPO_ROOT = Path(__file__).resolve().parent.parent
MEDIA_DIR = REPO_ROOT / "media"
FIXTURES_DIR = REPO_ROOT / "fixtures"


class Settings(BaseSettings):
    model_config = SettingsConfigDict(
        env_file=REPO_ROOT / ".env",
        env_file_encoding="utf-8",
        extra="ignore",
    )

    # Database (required)
    database_url: str
    # v2's tables live in this schema. Default "public"; set to e.g. "ugc" to share
    # an existing Supabase project without touching its other schemas (SPEC_NEW §3).
    db_schema: str = "public"

    # Supabase Storage — when set, avatar/product image uploads go to a public
    # bucket here instead of local disk (so everything lives in Supabase).
    supabase_url: str | None = None
    supabase_service_role_key: str | None = None
    supabase_bucket: str = "startframes"

    # Anthropic
    anthropic_api_key: str | None = None
    anthropic_model: str = "claude-sonnet-4-6"

    # Vertex AI / Veo
    google_cloud_project: str | None = None
    google_application_credentials: str | None = None
    vertex_location: str | None = None
    veo_model_id: str | None = None
    nano_banana_model: str | None = None     # Nano Banana Pro (Gemini image) on Vertex — §16.3

    # Windsor.ai (ad-metrics ingest — SPEC_NEW §7.6)
    windsor_api_key: str | None = None
    windsor_connector: str = "facebook"      # configured connector (Meta now; TikTok later)
    windsor_fields: str | None = None        # optional override; default = ad-level daily metrics

    # Meta (publish only — ingest is Windsor.ai above)
    meta_access_token: str | None = None
    meta_ad_account_id: str | None = None
    meta_api_version: str | None = None
    meta_test_campaign_id: str | None = None
    meta_page_id: str | None = None

    # Behavior / guardrails
    dry_run: bool = True
    max_generations_per_day: int = 40
    qc_pass_threshold: float = 0.85
    qc_flag_threshold: float = 0.70
    max_segment_attempts: int = 3

    # Video engine (SPEC_NEW §11)
    veo_resolution: str = "720p"            # all clips 720p, exactly like the MVP
    seed_takes: int = 2                      # hook seed candidates to generate (§11.3)
    seed_autopick: bool = True               # auto-pick best hook take via QC; human override
    veo_rai_autoretry: bool = False          # OFF = surface safety blocks (v1 default, §12.5)
    veo_rai_rephrase: bool = True            # LEGACY — auto-retry now swaps the SEED, not words (§12.5)
    veo_rai_max_retries: int = 3             # auto rephrase+retry loop length per safety block (§12.5)
    # Speaking-pace model for dynamic duration (§11.1). These MIRROR the defaults
    # baked into pipeline/duration.py; re-pacing is a deliberate change to both.
    words_per_second: float = 2.3
    tail_budget_s: float = 0.7

    # B-roll (Seedance, SPEC_NEW §15)
    seedance_provider: str = "volcengine"    # fal | replicate | volcengine (owner uses Volcengine Ark)
    seedance_api_key: str | None = None      # Volcengine Ark API key (ARK_API_KEY)
    seedance_model: str = "doubao-seedance-1-0-lite-i2v-250428"  # verify in your Ark console
    seedance_base_url: str = "https://ark.cn-beijing.volces.com/api/v3"

    # Assembly (SPEC_NEW §11.4)
    loudnorm_target_i: float = -14.0         # integrated LUFS
    caption_max_words_per_line: int = 4      # 2–4 words/line, burned ASS
    captions_enabled: bool = True            # best-effort; skipped if ASR unavailable

    # QC / ASR
    kb_whisper_model: str = "KBLab/kb-whisper-large"
    kb_whisper_fallback_model: str = "KBLab/kb-whisper-medium"
    kb_whisper_device: str = "auto"
    kb_whisper_compute_type: str = ""

    # Rules
    target_cpa: float = 300.0

    # Approval UI
    approval_ui_user: str = "admin"
    approval_ui_password: str | None = None

    def require(self, name: str) -> str:
        """Return a config value, failing loudly if it is unset/empty."""
        value = getattr(self, name.lower(), None)
        if value is None or (isinstance(value, str) and not value.strip()):
            raise RuntimeError(
                f"Missing required configuration: {name.upper()}. "
                f"Set it in .env (see .env.example)."
            )
        return value


@lru_cache(maxsize=1)
def get_settings() -> Settings:
    return Settings()  # type: ignore[call-arg]  # database_url comes from env


def reset_settings_cache() -> None:
    """Test helper: force re-read of the environment."""
    get_settings.cache_clear()