from pydantic_settings import BaseSettings
from pydantic import field_validator
from typing import Optional


_DEFAULT_SECRET_KEY = "your-secret-key-change-in-production-use-openssl-rand-hex-32"


class Settings(BaseSettings):
    # Application
    APP_NAME: str = "ResolutionFlow"
    DEBUG: bool = False
    API_V1_PREFIX: str = "/api/v1"

    # Database - Railway provides DATABASE_URL, we convert it for asyncpg
    DATABASE_URL: str = "postgresql+asyncpg://postgres:postgres@localhost:5432/patherly"

    @field_validator("DATABASE_URL", mode="before")
    @classmethod
    def convert_database_url(cls, v: str) -> str:
        """Convert standard postgres URL to asyncpg format."""
        if v.startswith("postgresql://"):
            return v.replace("postgresql://", "postgresql+asyncpg://", 1)
        return v

    # Sync URL for Alembic migrations. Defaults to DATABASE_URL (sync-converted).
    # Set explicitly in .env to use a different role for migrations (e.g. superuser)
    # when DATABASE_URL has been switched to the app role.
    DATABASE_URL_SYNC: str = ""

    @field_validator("DATABASE_URL_SYNC", mode="before")
    @classmethod
    def default_database_url_sync(cls, v: str, info) -> str:
        """Fall back to sync-converted DATABASE_URL if not explicitly set."""
        if not v:
            base = info.data.get("DATABASE_URL", "")
            return base.replace("postgresql+asyncpg://", "postgresql://", 1)
        return v

    # Admin database — resolutionflow_admin role, BYPASSRLS.
    # Used by /admin/* endpoints. Defaults to DATABASE_URL for local dev.
    ADMIN_DATABASE_URL: str = ""

    @field_validator("ADMIN_DATABASE_URL", mode="before")
    @classmethod
    def default_admin_database_url(cls, v: str, info) -> str:
        """Fall back to DATABASE_URL if ADMIN_DATABASE_URL is not set."""
        if not v:
            return info.data.get("DATABASE_URL", "")
        if v.startswith("postgresql://"):
            return v.replace("postgresql://", "postgresql+asyncpg://", 1)
        return v

    # JWT Settings
    SECRET_KEY: str = _DEFAULT_SECRET_KEY

    @field_validator("SECRET_KEY", mode="after")
    @classmethod
    def reject_default_secret_in_production(cls, v: str, info) -> str:
        """Fail loudly if the default secret key is used outside of DEBUG mode."""
        debug = info.data.get("DEBUG", False)
        if v == _DEFAULT_SECRET_KEY and not debug:
            raise ValueError(
                "SECRET_KEY must be set to a secure value in production. "
                "Generate one with: openssl rand -hex 32"
            )
        return v
    ALGORITHM: str = "HS256"
    ACCESS_TOKEN_EXPIRE_MINUTES: int = 5
    REFRESH_TOKEN_EXPIRE_DAYS: int = 7

    # Security
    BCRYPT_ROUNDS: int = 12

    # Security Headers
    CSP_REPORT_ONLY: bool = True  # Set False to enforce CSP
    CSP_EXTRA_SCRIPT_SOURCES: list[str] = []  # Additional script-src domains
    CSP_EXTRA_CONNECT_SOURCES: list[str] = []  # Additional connect-src domains

    # Registration
    REQUIRE_INVITE_CODE: bool = True  # Set to False to allow open registration

    # Email (Resend)
    RESEND_API_KEY: Optional[str] = None
    FROM_EMAIL: str = "ResolutionFlow <invites@resolutionflow.com>"
    FEEDBACK_EMAIL: Optional[str] = None
    SALES_LEAD_RECIPIENT_EMAIL: str = "sales@resolutionflow.com"

    @property
    def email_enabled(self) -> bool:
        """Check if email sending is configured."""
        return self.RESEND_API_KEY is not None

    # Stripe
    STRIPE_SECRET_KEY: Optional[str] = None
    STRIPE_PUBLISHABLE_KEY: Optional[str] = None
    STRIPE_WEBHOOK_SECRET: Optional[str] = None
    SELF_SERVE_ENABLED: bool = False

    @property
    def stripe_enabled(self) -> bool:
        """Check if Stripe is configured."""
        return bool(self.STRIPE_SECRET_KEY)

    # AI Flow Builder
    ANTHROPIC_API_KEY: Optional[str] = None
    AI_MODEL: str = "claude-sonnet-4-6"
    AI_CONVERSATION_TTL_HOURS: int = 24
    AI_MAX_CALLS_PER_FLOW: int = 10
    AI_REQUEST_TIMEOUT_SECONDS: int = 120
    # AI Provider selection
    AI_PROVIDER: str = "anthropic"  # "gemini" or "anthropic"
    GOOGLE_AI_API_KEY: Optional[str] = None
    AI_MODEL_GEMINI: str = "gemini-2.5-flash"
    AI_MODEL_ANTHROPIC: str = "claude-sonnet-4-6"
    # Bound for the diagnostic assessment Sonnet call. Generation runs in a
    # FastAPI BackgroundTask (commit e8ba74e), so this no longer blocks the
    # senior's click — only how long we wait before publishing
    # `handoff_assessment_ready` with has_assessment=false. 15s was hitting
    # tail latency on Sonnet (timeout 03:57:35 in field testing 2026-04-29),
    # leaving the magic-moment placeholder permanent. 45s is the right
    # ceiling: well above Sonnet p99 for a 500-token output, far enough
    # below "the senior gives up watching" that we still surface SOMETHING
    # on persistent slowness.
    ESCALATION_AI_ASSESSMENT_TIMEOUT_SECONDS: int = 45

    # Model tier routing — maps action types to model tiers
    AI_MODEL_TIERS: dict[str, str] = {
        "fast": "claude-haiku-4-5-20251001",
        "standard": "claude-sonnet-4-6",
    }

    ACTION_MODEL_MAP: dict[str, str] = {
        "generate_full": "standard",
        "generate_branch": "standard",
        "modify_node": "fast",
        "add_steps": "standard",
        "quick_action": "fast",
        "open_chat": "standard",
        "variable_inference": "fast",
        "kb_convert": "standard",
        "script_build": "standard",
        "network_diagram_generate": "standard",
        # FlowPilot migration Phase 2 — short, latency-sensitive transformation
        # of an engineer's answer/check output into a candidate fact.
        # Doc Section 6.6 sets Haiku as the default; instrumentation tracks
        # disputed_fact_rate so we can escalate to Sonnet if quality drops.
        "fact_synthesis": "fast",
        # FlowPilot migration Phase 3 — resolution-note preview that ships to
        # the customer ticket. Sonnet because customer-facing artifact quality
        # matters more than latency; the in-process state_version cache keeps
        # cost manageable.
        "resolution_note": "standard",
        # FlowPilot migration Phase 4 — escalation handoff package. Parallel
        # to resolution_note: Sonnet, same cache story, no MCP.
        "escalation_package": "standard",
        # FlowPilot migration Phase 5 — extract a parameter schema from a
        # concrete rendered script so a draft_template can be proposed.
        # Creates a persistent library artifact on accept, so Sonnet.
        "template_extraction": "standard",
    }

    def get_model_for_action(self, action_type: str) -> str:
        """Resolve an action type to a concrete model name via tier routing."""
        tier = self.ACTION_MODEL_MAP.get(action_type, "standard")
        return self.AI_MODEL_TIERS.get(tier, self.AI_MODEL_TIERS["standard"])

    # MCP (Model Context Protocol) integrations
    ENABLE_MCP_MICROSOFT_LEARN: bool = True

    # Embedding / RAG
    VOYAGE_API_KEY: Optional[str] = None
    EMBEDDING_MODEL: str = "voyage-3.5"
    EMBEDDING_DIMENSIONS: int = 1024

    @property
    def ai_enabled(self) -> bool:
        """Check if any AI provider is configured."""
        return self.ANTHROPIC_API_KEY is not None or self.GOOGLE_AI_API_KEY is not None

    # Object Storage (Railway S3-compatible)
    STORAGE_ENDPOINT: str | None = None
    STORAGE_ACCESS_KEY: str | None = None
    STORAGE_SECRET_KEY: str | None = None
    STORAGE_BUCKET_NAME: str = "resolutionflow-uploads"
    STORAGE_REGION: str = "us-east-1"

    # ConnectWise PSA Integration
    # CW_CLIENT_ID is a product-level GUID registered at developer.connectwise.com
    # All MSP customers share this single clientId — it identifies ResolutionFlow as the integration
    CW_CLIENT_ID: Optional[str] = None

    @property
    def cw_enabled(self) -> bool:
        """Check if ConnectWise integration is configured."""
        return self.CW_CLIENT_ID is not None

    # OAuth providers (self-serve signup)
    GOOGLE_CLIENT_ID: Optional[str] = None
    GOOGLE_CLIENT_SECRET: Optional[str] = None
    MS_CLIENT_ID: Optional[str] = None
    MS_CLIENT_SECRET: Optional[str] = None
    OAUTH_REDIRECT_BASE: str = "http://localhost:5173"

    # Monitoring
    SENTRY_DSN: Optional[str] = None

    # Deployment – auto-seed test data on PR environments
    SEED_ON_DEPLOY: bool = False

    # CORS - set FRONTEND_URL in production (e.g., https://patherly.up.railway.app)
    CORS_ORIGINS: list[str] = ["http://localhost:3000", "http://localhost:5173", "http://localhost:5174"]
    FRONTEND_URL: Optional[str] = None
    # Allow all Railway PR environments (set to True in Railway env vars)
    ALLOW_RAILWAY_ORIGINS: bool = False

    @property
    def allowed_origins(self) -> list[str]:
        """Get all allowed CORS origins including FRONTEND_URL if set."""
        origins = self.CORS_ORIGINS.copy()
        if self.FRONTEND_URL and self.FRONTEND_URL not in origins:
            origins.append(self.FRONTEND_URL)
        return origins

    def is_origin_allowed(self, origin: str) -> bool:
        """Check if an origin is allowed, including Railway wildcard pattern."""
        if origin in self.allowed_origins:
            return True
        # Allow any *.up.railway.app origin for PR environments
        if self.ALLOW_RAILWAY_ORIGINS and origin.endswith(".up.railway.app"):
            return True
        return False

    class Config:
        env_file = ".env"
        case_sensitive = True
        extra = "ignore"  # Ignore extra env vars like DATABASE_URL_SYNC


settings = Settings()