"""
Data models for LLM Gateway MCP Server.

Defines model groups, pricing, request/response structures.
Per ADR-004: LLM Provider Abstraction.
"""

from dataclasses import dataclass, field
from datetime import UTC, datetime
from enum import Enum
from typing import Any

from pydantic import BaseModel, Field


class ModelGroup(str, Enum):
    """Model groups for routing LLM requests."""

    REASONING = "reasoning"  # Complex analysis, architecture decisions
    CODE = "code"  # Code writing and refactoring
    FAST = "fast"  # Quick tasks, simple queries
    VISION = "vision"  # Multimodal image analysis
    EMBEDDING = "embedding"  # Vector embeddings
    COST_OPTIMIZED = "cost_optimized"  # High-volume, non-critical
    SELF_HOSTED = "self_hosted"  # Privacy-sensitive, air-gapped

    # Aliases for backward compatibility with ADR-004
    HIGH_REASONING = "reasoning"
    CODE_GENERATION = "code"
    FAST_RESPONSE = "fast"


class Provider(str, Enum):
    """Supported LLM providers."""

    ANTHROPIC = "anthropic"
    OPENAI = "openai"
    GOOGLE = "google"
    ALIBABA = "alibaba"
    DEEPSEEK = "deepseek"


@dataclass
class ModelConfig:
    """Configuration for a specific model."""

    name: str  # Model identifier (e.g., "claude-3-opus-20240229")
    litellm_name: str  # LiteLLM model string (e.g., "anthropic/claude-3-opus-20240229")
    provider: Provider
    cost_per_1m_input: float  # USD per 1M input tokens
    cost_per_1m_output: float  # USD per 1M output tokens
    context_window: int  # Max context tokens
    max_output_tokens: int  # Max output tokens
    supports_vision: bool = False
    supports_streaming: bool = True
    supports_function_calling: bool = True


# Model configurations per ADR-004
MODEL_CONFIGS: dict[str, ModelConfig] = {
    # Anthropic models
    "claude-opus-4": ModelConfig(
        name="claude-opus-4",
        litellm_name="anthropic/claude-sonnet-4-20250514",  # Using sonnet-4 as opus-4 placeholder
        provider=Provider.ANTHROPIC,
        cost_per_1m_input=15.0,
        cost_per_1m_output=75.0,
        context_window=200000,
        max_output_tokens=8192,
        supports_vision=True,
    ),
    "claude-sonnet-4": ModelConfig(
        name="claude-sonnet-4",
        litellm_name="anthropic/claude-sonnet-4-20250514",
        provider=Provider.ANTHROPIC,
        cost_per_1m_input=3.0,
        cost_per_1m_output=15.0,
        context_window=200000,
        max_output_tokens=8192,
        supports_vision=True,
    ),
    "claude-haiku": ModelConfig(
        name="claude-haiku",
        litellm_name="anthropic/claude-3-5-haiku-20241022",
        provider=Provider.ANTHROPIC,
        cost_per_1m_input=1.0,
        cost_per_1m_output=5.0,
        context_window=200000,
        max_output_tokens=8192,
        supports_vision=True,
    ),
    # OpenAI models
    "gpt-4.1": ModelConfig(
        name="gpt-4.1",
        litellm_name="openai/gpt-4.1",
        provider=Provider.OPENAI,
        cost_per_1m_input=2.0,
        cost_per_1m_output=8.0,
        context_window=1047576,
        max_output_tokens=32768,
        supports_vision=True,
    ),
    "gpt-4.1-mini": ModelConfig(
        name="gpt-4.1-mini",
        litellm_name="openai/gpt-4.1-mini",
        provider=Provider.OPENAI,
        cost_per_1m_input=0.4,
        cost_per_1m_output=1.6,
        context_window=1047576,
        max_output_tokens=32768,
        supports_vision=True,
    ),
    # Google models
    "gemini-2.5-pro": ModelConfig(
        name="gemini-2.5-pro",
        litellm_name="gemini/gemini-2.5-pro",
        provider=Provider.GOOGLE,
        cost_per_1m_input=1.25,
        cost_per_1m_output=10.0,
        context_window=1048576,
        max_output_tokens=65536,
        supports_vision=True,
    ),
    "gemini-2.0-flash": ModelConfig(
        name="gemini-2.0-flash",
        litellm_name="gemini/gemini-2.0-flash",
        provider=Provider.GOOGLE,
        cost_per_1m_input=0.1,
        cost_per_1m_output=0.4,
        context_window=1048576,
        max_output_tokens=8192,
        supports_vision=True,
    ),
    # Alibaba models
    "qwen-max": ModelConfig(
        name="qwen-max",
        litellm_name="alibaba/qwen-max",
        provider=Provider.ALIBABA,
        cost_per_1m_input=2.0,
        cost_per_1m_output=6.0,
        context_window=32768,
        max_output_tokens=8192,
        supports_vision=False,
    ),
    # DeepSeek models
    "deepseek-coder": ModelConfig(
        name="deepseek-coder",
        litellm_name="deepseek/deepseek-coder",
        provider=Provider.DEEPSEEK,
        cost_per_1m_input=0.14,
        cost_per_1m_output=0.28,
        context_window=128000,
        max_output_tokens=8192,
        supports_vision=False,
    ),
    "deepseek-chat": ModelConfig(
        name="deepseek-chat",
        litellm_name="deepseek/deepseek-chat",
        provider=Provider.DEEPSEEK,
        cost_per_1m_input=0.14,
        cost_per_1m_output=0.28,
        context_window=128000,
        max_output_tokens=8192,
        supports_vision=False,
    ),
    # Embedding models
    "text-embedding-3-large": ModelConfig(
        name="text-embedding-3-large",
        litellm_name="openai/text-embedding-3-large",
        provider=Provider.OPENAI,
        cost_per_1m_input=0.13,
        cost_per_1m_output=0.0,
        context_window=8191,
        max_output_tokens=0,
        supports_vision=False,
        supports_streaming=False,
        supports_function_calling=False,
    ),
    "voyage-3": ModelConfig(
        name="voyage-3",
        litellm_name="voyage/voyage-3",
        provider=Provider.ANTHROPIC,  # Voyage via Anthropic partnership
        cost_per_1m_input=0.06,
        cost_per_1m_output=0.0,
        context_window=32000,
        max_output_tokens=0,
        supports_vision=False,
        supports_streaming=False,
        supports_function_calling=False,
    ),
}


@dataclass
class ModelGroupConfig:
    """Configuration for a model group with failover chain."""

    primary: str  # Primary model name
    fallbacks: list[str]  # Fallback model names in order
    description: str

    def get_all_models(self) -> list[str]:
        """Get all models in priority order."""
        return [self.primary, *self.fallbacks]


# Model group configurations per ADR-004
MODEL_GROUPS: dict[ModelGroup, ModelGroupConfig] = {
    ModelGroup.REASONING: ModelGroupConfig(
        primary="claude-opus-4",
        fallbacks=["gpt-4.1", "gemini-2.5-pro", "qwen-max"],
        description="Complex analysis, architecture decisions",
    ),
    ModelGroup.CODE: ModelGroupConfig(
        primary="claude-sonnet-4",
        fallbacks=["gpt-4.1", "deepseek-coder"],
        description="Code writing and refactoring",
    ),
    ModelGroup.FAST: ModelGroupConfig(
        primary="claude-haiku",
        fallbacks=["gpt-4.1-mini", "gemini-2.0-flash"],
        description="Quick tasks, simple queries",
    ),
    ModelGroup.VISION: ModelGroupConfig(
        primary="claude-sonnet-4",
        fallbacks=["gpt-4.1", "gemini-2.5-pro"],
        description="Multimodal image analysis",
    ),
    ModelGroup.EMBEDDING: ModelGroupConfig(
        primary="text-embedding-3-large",
        fallbacks=["voyage-3"],
        description="Vector embeddings",
    ),
    ModelGroup.COST_OPTIMIZED: ModelGroupConfig(
        primary="qwen-max",
        fallbacks=["deepseek-chat"],
        description="High-volume, non-critical tasks",
    ),
    ModelGroup.SELF_HOSTED: ModelGroupConfig(
        primary="deepseek-chat",
        fallbacks=["qwen-max"],
        description="Privacy-sensitive, air-gapped",
    ),
}


# Agent type to model group mapping per ADR-004
AGENT_TYPE_MODEL_PREFERENCES: dict[str, ModelGroup] = {
    "product_owner": ModelGroup.REASONING,
    "software_architect": ModelGroup.REASONING,
    "software_engineer": ModelGroup.CODE,
    "qa_engineer": ModelGroup.CODE,
    "devops_engineer": ModelGroup.FAST,
    "project_manager": ModelGroup.FAST,
    "business_analyst": ModelGroup.REASONING,
}


class ChatMessage(BaseModel):
    """A single chat message."""

    role: str = Field(..., description="Message role: system, user, assistant, tool")
    content: str | list[dict[str, Any]] = Field(..., description="Message content")
    name: str | None = Field(default=None, description="Optional name for the message")
    tool_calls: list[dict[str, Any]] | None = Field(
        default=None, description="Tool calls if role is assistant"
    )
    tool_call_id: str | None = Field(
        default=None, description="Tool call ID if role is tool"
    )


class CompletionRequest(BaseModel):
    """Request for chat completion."""

    project_id: str = Field(..., description="Project ID for cost attribution")
    agent_id: str = Field(..., description="Agent ID making the request")
    messages: list[ChatMessage] = Field(..., description="Chat messages")
    model_group: ModelGroup = Field(
        default=ModelGroup.REASONING, description="Model group for routing"
    )
    model_override: str | None = Field(
        default=None, description="Specific model to use (bypasses routing)"
    )
    max_tokens: int = Field(
        default=4096, ge=1, le=32768, description="Max output tokens"
    )
    temperature: float = Field(
        default=0.7, ge=0.0, le=2.0, description="Sampling temperature"
    )
    stream: bool = Field(default=False, description="Enable streaming response")
    session_id: str | None = Field(
        default=None, description="Session ID for conversation tracking"
    )
    metadata: dict[str, Any] = Field(
        default_factory=dict, description="Additional metadata"
    )


class UsageStats(BaseModel):
    """Token usage statistics."""

    prompt_tokens: int = Field(default=0, description="Input tokens used")
    completion_tokens: int = Field(default=0, description="Output tokens generated")
    total_tokens: int = Field(default=0, description="Total tokens")
    cost_usd: float = Field(default=0.0, description="Estimated cost in USD")

    @classmethod
    def from_response(
        cls, prompt_tokens: int, completion_tokens: int, model_config: ModelConfig
    ) -> "UsageStats":
        """Create usage stats from token counts and model config."""
        input_cost = (prompt_tokens / 1_000_000) * model_config.cost_per_1m_input
        output_cost = (completion_tokens / 1_000_000) * model_config.cost_per_1m_output
        return cls(
            prompt_tokens=prompt_tokens,
            completion_tokens=completion_tokens,
            total_tokens=prompt_tokens + completion_tokens,
            cost_usd=round(input_cost + output_cost, 6),
        )


class CompletionResponse(BaseModel):
    """Response from chat completion."""

    id: str = Field(..., description="Unique response ID")
    model: str = Field(..., description="Model that generated the response")
    provider: str = Field(..., description="Provider used")
    content: str = Field(..., description="Generated content")
    finish_reason: str = Field(
        default="stop", description="Reason for completion finish"
    )
    usage: UsageStats = Field(default_factory=UsageStats, description="Token usage")
    created_at: datetime = Field(
        default_factory=lambda: datetime.now(UTC), description="Response timestamp"
    )
    metadata: dict[str, Any] = Field(
        default_factory=dict, description="Additional metadata"
    )


class StreamChunk(BaseModel):
    """A chunk from a streaming response."""

    id: str = Field(..., description="Chunk ID")
    delta: str = Field(default="", description="Content delta")
    finish_reason: str | None = Field(default=None, description="Finish reason if done")
    usage: UsageStats | None = Field(
        default=None, description="Usage stats (only on final chunk)"
    )


class EmbeddingRequest(BaseModel):
    """Request for text embeddings."""

    project_id: str = Field(..., description="Project ID for cost attribution")
    agent_id: str = Field(..., description="Agent ID making the request")
    texts: list[str] = Field(..., min_length=1, description="Texts to embed")
    model: str = Field(default="text-embedding-3-large", description="Embedding model")


class EmbeddingResponse(BaseModel):
    """Response from embedding generation."""

    model: str = Field(..., description="Model used")
    embeddings: list[list[float]] = Field(..., description="Embedding vectors")
    usage: UsageStats = Field(default_factory=UsageStats, description="Token usage")


@dataclass
class CostRecord:
    """A single cost record for tracking."""

    project_id: str
    agent_id: str
    model: str
    prompt_tokens: int
    completion_tokens: int
    cost_usd: float
    timestamp: datetime = field(default_factory=lambda: datetime.now(UTC))
    session_id: str | None = None
    request_id: str | None = None


class UsageReport(BaseModel):
    """Usage report for a project or agent."""

    entity_id: str = Field(..., description="Project or agent ID")
    entity_type: str = Field(..., description="'project' or 'agent'")
    period: str = Field(..., description="Report period (hour, day, month)")
    period_start: datetime = Field(..., description="Period start time")
    period_end: datetime = Field(..., description="Period end time")
    total_requests: int = Field(default=0, description="Total requests")
    total_tokens: int = Field(default=0, description="Total tokens used")
    total_cost_usd: float = Field(default=0.0, description="Total cost in USD")
    by_model: dict[str, dict[str, Any]] = Field(
        default_factory=dict, description="Breakdown by model"
    )
    by_agent: dict[str, dict[str, Any]] = Field(
        default_factory=dict, description="Breakdown by agent (for project reports)"
    )


class ModelInfo(BaseModel):
    """Information about an available model."""

    name: str = Field(..., description="Model name")
    provider: str = Field(..., description="Provider name")
    cost_per_1m_input: float = Field(..., description="Input cost per 1M tokens")
    cost_per_1m_output: float = Field(..., description="Output cost per 1M tokens")
    context_window: int = Field(..., description="Max context tokens")
    max_output_tokens: int = Field(..., description="Max output tokens")
    supports_vision: bool = Field(..., description="Vision capability")
    supports_streaming: bool = Field(..., description="Streaming capability")
    supports_function_calling: bool = Field(..., description="Function calling")
    available: bool = Field(default=True, description="Provider configured")

    @classmethod
    def from_config(cls, config: ModelConfig, available: bool = True) -> "ModelInfo":
        """Create ModelInfo from ModelConfig."""
        return cls(
            name=config.name,
            provider=config.provider.value,
            cost_per_1m_input=config.cost_per_1m_input,
            cost_per_1m_output=config.cost_per_1m_output,
            context_window=config.context_window,
            max_output_tokens=config.max_output_tokens,
            supports_vision=config.supports_vision,
            supports_streaming=config.supports_streaming,
            supports_function_calling=config.supports_function_calling,
            available=available,
        )


class ModelGroupInfo(BaseModel):
    """Information about a model group."""

    name: str = Field(..., description="Group name")
    description: str = Field(..., description="Group description")
    primary_model: str = Field(..., description="Primary model")
    fallback_models: list[str] = Field(..., description="Fallback models")
    available: bool = Field(default=True, description="At least one model available")