#!/usr/bin/env python3
"""
Generic Pipeline API endpoints.

Provides a unified API for all registered pipelines:
- List available pipelines
- Get pipeline details and metadata
- Execute pipelines
- Get dashboard configuration
- Get widget data
- List execution history
"""

import logging
from typing import Any

import asyncpg
from fastapi import APIRouter, HTTPException, Query
from pydantic import BaseModel, Field

log = logging.getLogger(__name__)

# Create router
router = APIRouter(prefix="/api/pipelines", tags=["pipelines"])

# Database pool (set by main server)
_pool: asyncpg.Pool | None = None

# Pipeline instances cache
_pipeline_instances: dict[str, Any] = {}


def set_database(pool: asyncpg.Pool) -> None:
    """Set the database pool for pipeline operations."""
    global _pool
    _pool = pool


# ==================== Pydantic Models ====================


class PipelineInfo(BaseModel):
    """Summary information about a pipeline."""

    id: str = Field(..., description="Pipeline identifier")
    name: str = Field(..., description="Display name")
    description: str = Field(..., description="Human-readable description")
    version: str = Field(..., description="Semantic version")
    is_enabled: bool = Field(..., description="Whether pipeline is enabled")
    stages: list[str] = Field(..., description="Available stages")
    input_type: str = Field(..., description="Expected input type")


class PipelineDetail(PipelineInfo):
    """Detailed pipeline information."""

    module_path: str = Field(..., description="Python module path")
    config: dict[str, Any] | None = Field(None, description="Pipeline configuration")
    created_at: str | None = Field(None, description="Registration timestamp")
    updated_at: str | None = Field(None, description="Last update timestamp")


class ExecuteRequest(BaseModel):
    """Request to execute a pipeline."""

    job_id: str | None = Field(None, description="Job ID to process")
    business_id: str | None = Field(None, description="Business identifier")
    input_data: dict[str, Any] | None = Field(None, description="Direct input data")
    stages: list[str] | None = Field(None, description="Stages to run (default: all)")
    options: dict[str, Any] | None = Field(None, description="Pipeline-specific options")


class ExecuteResponse(BaseModel):
    """Response from pipeline execution."""

    execution_id: str = Field(..., description="Execution identifier")
    pipeline_id: str = Field(..., description="Pipeline that was executed")
    success: bool = Field(..., description="Whether execution succeeded")
    stages_run: list[str] = Field(..., description="Stages that were run")
    error: str | None = Field(None, description="Error message if failed")


class ExecutionSummary(BaseModel):
    """Summary of a pipeline execution."""

    id: str = Field(..., description="Execution identifier")
    pipeline_id: str = Field(..., description="Pipeline identifier")
    job_id: str | None = Field(None, description="Associated job ID")
    business_id: str | None = Field(None, description="Business identifier")
    status: str = Field(..., description="Execution status")
    stages_requested: list[str] = Field(..., description="Stages requested")
    stages_completed: list[str] = Field(..., description="Stages completed")
    error_message: str | None = Field(None, description="Error if failed")
    started_at: str | None = Field(None, description="Start timestamp")
    completed_at: str | None = Field(None, description="Completion timestamp")
    created_at: str | None = Field(None, description="Creation timestamp")


class DashboardSectionModel(BaseModel):
    """Dashboard section configuration."""

    id: str
    title: str
    description: str | None = None
    widgets: list[dict[str, Any]]
    collapsed: bool | None = None


class DashboardConfigModel(BaseModel):
    """Dashboard configuration for a pipeline."""

    pipeline_id: str
    title: str
    description: str | None = None
    sections: list[DashboardSectionModel]
    default_time_range: str | None = None
    refresh_interval: int | None = None


# ==================== Helper Functions ====================


async def _get_pipeline_instance(pipeline_id: str) -> Any:
    """Get or create a pipeline instance."""
    if pipeline_id in _pipeline_instances:
        return _pipeline_instances[pipeline_id]

    if not _pool:
        raise HTTPException(status_code=503, detail="Database not initialized")

    # Look up pipeline in registry
    async with _pool.acquire() as conn:
        row = await conn.fetchrow(
            """
            SELECT pipeline_id, module_path, is_enabled
            FROM pipeline.registry
            WHERE pipeline_id = $1
            """,
            pipeline_id,
        )

    if not row:
        raise HTTPException(status_code=404, detail=f"Pipeline not found: {pipeline_id}")

    if not row["is_enabled"]:
        raise HTTPException(status_code=400, detail=f"Pipeline is disabled: {pipeline_id}")

    # Import and instantiate
    try:
        module_path = row["module_path"]
        module_name, class_name = module_path.rsplit(":", 1)

        import importlib

        module = importlib.import_module(module_name)
        cls = getattr(module, class_name)
        instance = cls()

        # Initialize the pipeline
        await instance.initialize()

        _pipeline_instances[pipeline_id] = instance
        return instance

    except Exception as e:
        log.exception(f"Failed to load pipeline {pipeline_id}")
        raise HTTPException(
            status_code=500, detail=f"Failed to load pipeline: {e}"
        )


# ==================== API Endpoints ====================


@router.get("/", response_model=list[PipelineInfo])
async def list_pipelines(
    enabled_only: bool = Query(True, description="Only return enabled pipelines"),
) -> list[PipelineInfo]:
    """
    List all registered pipelines.

    Returns summary information for each pipeline including name, version,
    available stages, and enabled status.
    """
    if not _pool:
        raise HTTPException(status_code=503, detail="Database not initialized")

    async with _pool.acquire() as conn:
        if enabled_only:
            rows = await conn.fetch(
                """
                SELECT pipeline_id, name, description, version,
                       is_enabled, stages, input_type
                FROM pipeline.registry
                WHERE is_enabled = TRUE
                ORDER BY name
                """
            )
        else:
            rows = await conn.fetch(
                """
                SELECT pipeline_id, name, description, version,
                       is_enabled, stages, input_type
                FROM pipeline.registry
                ORDER BY name
                """
            )

    return [
        PipelineInfo(
            id=row["pipeline_id"],
            name=row["name"],
            description=row["description"] or "",
            version=row["version"],
            is_enabled=row["is_enabled"],
            stages=row["stages"] or [],
            input_type=row["input_type"] or "dict",
        )
        for row in rows
    ]


@router.get("/{pipeline_id}", response_model=PipelineDetail)
async def get_pipeline(pipeline_id: str) -> PipelineDetail:
    """
    Get detailed information about a pipeline.

    Includes metadata, configuration, and registration timestamps.
    """
    if not _pool:
        raise HTTPException(status_code=503, detail="Database not initialized")

    async with _pool.acquire() as conn:
        row = await conn.fetchrow(
            """
            SELECT pipeline_id, name, description, version, module_path,
                   is_enabled, stages, input_type, config,
                   created_at, updated_at
            FROM pipeline.registry
            WHERE pipeline_id = $1
            """,
            pipeline_id,
        )

    if not row:
        raise HTTPException(status_code=404, detail=f"Pipeline not found: {pipeline_id}")

    return PipelineDetail(
        id=row["pipeline_id"],
        name=row["name"],
        description=row["description"] or "",
        version=row["version"],
        is_enabled=row["is_enabled"],
        stages=row["stages"] or [],
        input_type=row["input_type"] or "dict",
        module_path=row["module_path"],
        config=row["config"],
        created_at=row["created_at"].isoformat() if row["created_at"] else None,
        updated_at=row["updated_at"].isoformat() if row["updated_at"] else None,
    )


@router.post("/{pipeline_id}/execute", response_model=ExecuteResponse)
async def execute_pipeline(
    pipeline_id: str,
    request: ExecuteRequest,
) -> ExecuteResponse:
    """
    Execute a pipeline.

    The pipeline can be executed with:
    - A job_id to process an existing scraper job
    - Direct input_data for testing
    - Specific stages to run (default: all)
    """
    import uuid

    pipeline = await _get_pipeline_instance(pipeline_id)

    # Prepare input data
    input_data = request.input_data or {}
    if request.job_id:
        input_data["job_id"] = request.job_id
    if request.business_id:
        input_data["business_id"] = request.business_id

    # Create execution record
    execution_id = str(uuid.uuid4())
    stages = request.stages or pipeline.get_stage_names()

    if _pool:
        async with _pool.acquire() as conn:
            await conn.execute(
                """
                INSERT INTO pipeline.executions (
                    id, pipeline_id, job_id, business_id,
                    status, stages_requested, created_at
                )
                VALUES ($1, $2, $3, $4, 'running', $5, NOW())
                """,
                uuid.UUID(execution_id),
                pipeline_id,
                uuid.UUID(request.job_id) if request.job_id else None,
                request.business_id,
                stages,
            )

    try:
        # Execute pipeline
        result = await pipeline.process(input_data, stages=stages)

        # Update execution status
        if _pool:
            async with _pool.acquire() as conn:
                await conn.execute(
                    """
                    UPDATE pipeline.executions
                    SET status = $2, stages_completed = $3, error_message = $4,
                        completed_at = NOW()
                    WHERE id = $1
                    """,
                    uuid.UUID(execution_id),
                    "completed" if result.success else "failed",
                    result.stages_run,
                    result.error,
                )

        return ExecuteResponse(
            execution_id=execution_id,
            pipeline_id=pipeline_id,
            success=result.success,
            stages_run=result.stages_run,
            error=result.error,
        )

    except Exception as e:
        log.exception(f"Pipeline execution failed: {e}")

        # Update execution status
        if _pool:
            async with _pool.acquire() as conn:
                await conn.execute(
                    """
                    UPDATE pipeline.executions
                    SET status = 'failed', error_message = $2, completed_at = NOW()
                    WHERE id = $1
                    """,
                    uuid.UUID(execution_id),
                    str(e),
                )

        raise HTTPException(status_code=500, detail=f"Execution failed: {e}")


@router.get("/{pipeline_id}/executions", response_model=list[ExecutionSummary])
async def list_executions(
    pipeline_id: str,
    status: str | None = Query(None, description="Filter by status"),
    limit: int = Query(50, ge=1, le=200, description="Max results"),
    offset: int = Query(0, ge=0, description="Offset for pagination"),
) -> list[ExecutionSummary]:
    """
    List execution history for a pipeline.

    Can filter by status and paginate results.
    """
    if not _pool:
        raise HTTPException(status_code=503, detail="Database not initialized")

    conditions = ["pipeline_id = $1"]
    params: list[Any] = [pipeline_id]
    param_idx = 2

    if status:
        conditions.append(f"status = ${param_idx}")
        params.append(status)
        param_idx += 1

    where_clause = " AND ".join(conditions)

    async with _pool.acquire() as conn:
        rows = await conn.fetch(
            f"""
            SELECT id, pipeline_id, job_id, business_id, status,
                   stages_requested, stages_completed, error_message,
                   started_at, completed_at, created_at
            FROM pipeline.executions
            WHERE {where_clause}
            ORDER BY created_at DESC
            LIMIT ${param_idx} OFFSET ${param_idx + 1}
            """,
            *params,
            limit,
            offset,
        )

    return [
        ExecutionSummary(
            id=str(row["id"]),
            pipeline_id=row["pipeline_id"],
            job_id=str(row["job_id"]) if row["job_id"] else None,
            business_id=row["business_id"],
            status=row["status"],
            stages_requested=row["stages_requested"] or [],
            stages_completed=row["stages_completed"] or [],
            error_message=row["error_message"],
            started_at=row["started_at"].isoformat() if row["started_at"] else None,
            completed_at=row["completed_at"].isoformat() if row["completed_at"] else None,
            created_at=row["created_at"].isoformat() if row["created_at"] else None,
        )
        for row in rows
    ]


@router.get("/{pipeline_id}/dashboard", response_model=DashboardConfigModel)
async def get_dashboard_config(pipeline_id: str) -> DashboardConfigModel:
    """
    Get dashboard configuration for a pipeline.

    Returns the widget configuration that the frontend uses to render
    the pipeline's dynamic dashboard.
    """
    pipeline = await _get_pipeline_instance(pipeline_id)

    try:
        config = pipeline.get_dashboard_config()

        return DashboardConfigModel(
            pipeline_id=config["pipeline_id"],
            title=config["title"],
            description=config.get("description"),
            sections=[
                DashboardSectionModel(
                    id=s["id"],
                    title=s["title"],
                    description=s.get("description"),
                    widgets=s["widgets"],
                    collapsed=s.get("collapsed"),
                )
                for s in config["sections"]
            ],
            default_time_range=config.get("default_time_range"),
            refresh_interval=config.get("refresh_interval"),
        )

    except Exception as e:
        log.exception(f"Failed to get dashboard config: {e}")
        raise HTTPException(
            status_code=500, detail=f"Failed to get dashboard config: {e}"
        )


@router.get("/{pipeline_id}/widgets/{widget_id}")
async def get_widget_data(
    pipeline_id: str,
    widget_id: str,
    business_id: str | None = Query(None, description="Filter by business"),
    time_range: str = Query("30d", description="Time range (e.g., 7d, 30d, 90d)"),
    page: int = Query(1, ge=1, description="Page number for paginated widgets"),
    page_size: int = Query(10, ge=1, le=100, description="Items per page"),
) -> dict[str, Any]:
    """
    Get data for a specific dashboard widget.

    The response format depends on the widget type. Common formats:
    - stat_card: {value, trend, ...}
    - chart: {data: [{x, y, ...}, ...]}
    - table: {data: [...], total: n}
    """
    pipeline = await _get_pipeline_instance(pipeline_id)

    try:
        params = {
            "business_id": business_id,
            "time_range": time_range,
            "page": page,
            "page_size": page_size,
        }

        data = await pipeline.get_widget_data(widget_id, params)
        return data

    except Exception as e:
        log.exception(f"Failed to get widget data: {e}")
        raise HTTPException(
            status_code=500, detail=f"Failed to get widget data: {e}"
        )


@router.post("/{pipeline_id}/enable")
async def enable_pipeline(pipeline_id: str) -> dict[str, str]:
    """Enable a disabled pipeline."""
    if not _pool:
        raise HTTPException(status_code=503, detail="Database not initialized")

    async with _pool.acquire() as conn:
        result = await conn.execute(
            """
            UPDATE pipeline.registry
            SET is_enabled = TRUE, updated_at = NOW()
            WHERE pipeline_id = $1
            """,
            pipeline_id,
        )

    if result.split()[-1] == "0":
        raise HTTPException(status_code=404, detail=f"Pipeline not found: {pipeline_id}")

    # Clear cached instance
    _pipeline_instances.pop(pipeline_id, None)

    return {"status": "enabled", "pipeline_id": pipeline_id}


@router.post("/{pipeline_id}/disable")
async def disable_pipeline(pipeline_id: str) -> dict[str, str]:
    """Disable a pipeline."""
    if not _pool:
        raise HTTPException(status_code=503, detail="Database not initialized")

    async with _pool.acquire() as conn:
        result = await conn.execute(
            """
            UPDATE pipeline.registry
            SET is_enabled = FALSE, updated_at = NOW()
            WHERE pipeline_id = $1
            """,
            pipeline_id,
        )

    if result.split()[-1] == "0":
        raise HTTPException(status_code=404, detail=f"Pipeline not found: {pipeline_id}")

    # Clear cached instance
    _pipeline_instances.pop(pipeline_id, None)

    return {"status": "disabled", "pipeline_id": pipeline_id}


@router.get("/{pipeline_id}/health")
async def pipeline_health(pipeline_id: str) -> dict[str, Any]:
    """
    Check pipeline health.

    Returns health status and any issues detected.
    """
    pipeline = await _get_pipeline_instance(pipeline_id)

    try:
        health = await pipeline.health_check()
        return {
            "pipeline_id": pipeline_id,
            **health,
        }
    except Exception as e:
        return {
            "pipeline_id": pipeline_id,
            "healthy": False,
            "error": str(e),
        }