# ============================================================================
#  PYDANTIC MODELS
# ============================================================================

from pydantic import BaseModel, Field, validator, root_validator
from typing import List, Optional, Dict, Any, Literal, Union
from datetime import datetime
from enum import Enum

from .enums import TaskStatus, TaskType, TestCasePriority, TestCaseType, TestCaseCategory, OutputFormat
from app.config import Config


# ============================================================================
#  FRONTEND-COMPATIBLE ENUMS (Match PM Tool Frontend)
# ============================================================================

class TaskStatusFrontend(str, Enum):
    """Status values matching frontend test-case-form.tsx"""
    DRAFT = "Draft"
    READY = "Ready"
    IN_PROGRESS = "In Progress"
    BLOCKED = "Blocked"
    COMPLETED = "Completed"
    PASSED = "Passed"
    FAILED = "Failed"
    SKIPPED = "Skipped"


class TaskPriorityFrontend(str, Enum):
    """Priority values matching frontend test-case-form.tsx"""
    CRITICAL = "Critical"
    HIGH = "High"
    MEDIUM = "Medium"
    LOW = "Low"


class TaskSeverityFrontend(str, Enum):
    """Severity values matching frontend test-case-form.tsx"""
    BLOCKER = "Blocker"
    CRITICAL = "Critical"
    MAJOR = "Major"
    MINOR = "Minor"
    TRIVIAL = "Trivial"


class TaskEnvironmentFrontend(str, Enum):
    """Environment values matching frontend test-case-form.tsx"""
    DEVELOPMENT = "Development"
    TESTING = "Testing"
    STAGING = "Staging"
    PRODUCTION = "Production"


class Credentials(BaseModel):
    email: str = Field(..., description="PM Tool email")
    password: str = Field(..., description="PM Tool password")
    
    @validator('email')
    def validate_email(cls, v):
        if '@' not in v:
            raise ValueError('Invalid email format')
        return v.lower()


class DateRange(BaseModel):
    from_date: Optional[str] = Field(None, alias="from", description="Start date (YYYY-MM-DD)")
    to_date: Optional[str] = Field(None, alias="to", description="End date (YYYY-MM-DD)")
    
    @validator('from_date', 'to_date')
    def validate_date(cls, v):
        if v:
            try:
                datetime.strptime(v, '%Y-%m-%d')
            except ValueError:
                raise ValueError('Date must be in YYYY-MM-DD format')
        return v


# ============================================================================
#  DOCUMENT PROCESSING MODELS
# ============================================================================

class AttachmentConfig(BaseModel):
    """Configuration for individual attachment processing"""
    attachment_id: Optional[str] = Field(None, description="Attachment ID from PM Tool")
    filename: str = Field(..., description="Filename")
    skip: bool = Field(False, description="Skip processing this attachment")
    skip_reason: Optional[str] = Field(None, description="Reason for skipping")
    priority: int = Field(0, ge=0, le=10, description="Processing priority (higher = first)")
    max_tokens: Optional[int] = Field(None, description="Max tokens to use from this document")


class DocumentProcessingConfig(BaseModel):
    """Global document processing configuration"""
    enabled: bool = Field(True, description="Enable document processing")
    max_total_tokens: int = Field(6000, ge=500, le=32000, description="Max total tokens for document context")
    max_chunk_tokens: int = Field(1500, ge=200, le=4000, description="Max tokens per chunk")
    overlap_tokens: int = Field(100, ge=0, le=500, description="Overlap between chunks")
    include_metadata: bool = Field(True, description="Include document metadata in context")
    auto_download: bool = Field(True, description="Auto-download attachments from PM Tool")
    download_dir: Optional[str] = Field(None, description="Directory to save downloaded files")


class ProjectSelection(BaseModel):
    """Project selection options"""
    project_id: Optional[int] = Field(None, description="Project ID")
    project_name: Optional[str] = Field(None, description="Project name (auto-resolved)")
    include_all_tasks: bool = Field(False, description="Include all tasks from project")


class GenerateRequest(BaseModel):
    # Authentication
    credentials: Credentials
    
    # Task Selection (provide at least one)
    task_id: Optional[int] = Field(None, description="Single task ID")
    task_ids: Optional[List[int]] = Field(None, description="Multiple task IDs")
    created_by_name: Optional[str] = Field(None, description="Filter by task creator")
    project_selection: Optional[ProjectSelection] = Field(None, description="Project selection options")
    
    # Legacy project_id for backward compatibility
    project_id: Optional[int] = Field(None, description="All tasks in project (legacy)")
    
    # Filters
    date_range: Optional[DateRange] = None
    status: Optional[List[TaskStatus]] = Field(None, description="Filter by task status")
    priority: Optional[List[TestCasePriority]] = None
    task_type: Optional[TaskType] = Field(TaskType.TASK, description="Task type filter")
    
    # Generation Settings
    test_case_count: int = Field(8, ge=1, le=15, description="Test cases per task")
    include_attachments: bool = Field(True, description="Fetch and analyze attachments")
    include_related_tasks: bool = Field(False, description="Cross-reference similar tasks")
    
    # Document Processing Settings
    document_processing: Optional[DocumentProcessingConfig] = Field(
        None, description="Document processing configuration"
    )
    attachment_configs: Optional[List[AttachmentConfig]] = Field(
        None, description="Per-attachment processing config (skip, priority, etc.)"
    )
    
    # AI Settings
    groq_model: str = Field(Config.GROQ_MODEL, description="Groq model to use")
    temperature: float = Field(Config.GROQ_TEMPERATURE, ge=0, le=1)
    
    # Output
    output_format: OutputFormat = Field(OutputFormat.JSON, description="Output format")
    include_metadata: bool = Field(True, description="Include generation metadata")
    
    @root_validator(skip_on_failure=True)
    def validate_task_selection(cls, values):
        # At least one selection method must be provided
        selections = [
            values.get('task_id'),
            values.get('task_ids'),
            values.get('created_by_name'),
            values.get('project_id'),
            values.get('project_selection'),
        ]
        if not any(selections):
            raise ValueError('Provide at least one task selection method (task_id, task_ids, created_by_name, project_id, or project_selection)')
        return values


class DocumentProcessingResult(BaseModel):
    """Result of document processing"""
    document_id: str
    filename: str
    processed: bool
    skipped: bool = False
    skip_reason: Optional[str] = None
    chunks_count: int = 0
    tokens_used: int = 0
    error: Optional[str] = None


class TestStep(BaseModel):
    step_number: int
    action: str
    expected_result: str
    test_data: Optional[str] = None


class TestCase(BaseModel):
    """Legacy test case format (kept for backward compatibility)"""
    test_case_id: str
    task_id: int
    task_code: str
    project_name: str
    issue_name: str
    feature_name: str
    task_name: str
    task_description: str
    created_by: str
    title: str
    objective: str
    preconditions: List[str]
    test_steps: List[TestStep]
    expected_outcome: str
    test_type: TestCaseType
    priority: TestCasePriority
    category: TestCaseCategory
    metadata: Optional[Dict[str, Any]] = None


# ============================================================================
#  FRONTEND-COMPATIBLE TEST CASE (Matches Task Interface)
# ============================================================================

class FrontendTestCase(BaseModel):
    """
    Test case format that matches the frontend Task interface exactly.
    This is what the frontend expects to save directly via tasksApi.create()
    
    Required fields (marked with * in frontend):
    - title: Test Case Title
    - description: Test Case Description
    
    All other fields are optional with sensible defaults.
    """
    # Core Identity
    type: str = Field(default="Test Case", description="Always 'Test Case' for test cases")
    id: Optional[int] = Field(default=None, description="Auto-generated by PM Tool DB")
    
    # Required Fields
    title: str = Field(..., description="Test case title (REQUIRED)")
    description: str = Field(..., description="Test case description (REQUIRED)")
    
    # Linking
    issuesId: Optional[int] = Field(default=None, description="Feature/Issue ID this test case belongs to")
    projectId: Optional[int] = Field(default=None, description="Project ID")
    
    # Status & Priority
    status: str = Field(default="Draft", description="Test case status")
    priority: Optional[str] = Field(default="Medium", description="Priority: Critical, High, Medium, Low")
    severity: Optional[str] = Field(default="Minor", description="Severity: Blocker, Critical, Major, Minor, Trivial")
    
    # Test Details (Tab 2: Test Steps)
    stepsToReproduce: Optional[str] = Field(default=None, description="Numbered test steps as text")
    inputs: Optional[str] = Field(default=None, description="Test data/inputs")
    expectedBehavior: Optional[str] = Field(default=None, description="Expected result")
    actualBehavior: Optional[str] = Field(default="", description="Actual result (filled during testing)")
    
    # Technical Details (Tab 3)
    rootCause: Optional[str] = Field(default="", description="Root cause (filled after bug analysis)")
    resolution: Optional[str] = Field(default="", description="Resolution (filled after fix)")
    
    # Additional Fields
    environment: Optional[str] = Field(default="Staging", description="Test environment")
    version: Optional[str] = Field(default="", description="Version being tested")
    url: Optional[str] = Field(default="", description="Related URL")
    
    # Assignment & Dates
    assignedTo: Optional[int] = Field(default=None, description="Assigned employee ID")
    stateDate: Optional[str] = Field(default=None, description="Start date (ISO format)")
    endDate: Optional[str] = Field(default=None, description="End date (ISO format)")
    
    # Auto-generated fields
    taskCode: Optional[str] = Field(default=None, description="Auto-generated task code")
    createdAt: Optional[str] = Field(default=None, description="Creation timestamp")
    createdBy: Optional[int] = Field(default=None, description="Creator employee ID")
    createdByName: Optional[str] = Field(default=None, description="Creator name")
    
    # Related names (for display)
    projectName: Optional[str] = Field(default=None, description="Project name")
    issueName: Optional[str] = Field(default=None, description="Issue/Feature name")
    deliverableName: Optional[str] = Field(default=None, description="Deliverable/Feature name")
    
    # Sprint info
    sprintName: Optional[str] = Field(default=None, description="Sprint name")
    estimates: Optional[str] = Field(default="", description="Time estimate")
    esUnit: Optional[int] = Field(default=0, description="Estimate unit")
    remainingHr: Optional[int] = Field(default=0, description="Remaining hours")
    
    # Link back to original task (for reference)
    related_task_id: Optional[int] = Field(default=None, description="Original task ID this was generated from")
    related_task_code: Optional[str] = Field(default=None, description="Original task code")
    
    class Config:
        extra = "allow"  # Allow additional fields from PM Tool


class GenerateResponse(BaseModel):
    """Legacy response format"""
    success: bool
    message: str
    total_tasks_processed: int
    total_test_cases_generated: int
    failed_tasks: List[Dict[str, Any]] = []
    test_cases: List[TestCase]
    metadata: Optional[Dict[str, Any]] = None
    download_url: Optional[str] = None


class FrontendGenerateResponse(BaseModel):
    """
    Response format for frontend integration.
    Returns test cases in Task format ready for tasksApi.create()
    """
    success: bool
    message: str
    feature_id: Optional[int] = None
    feature_name: Optional[str] = None
    generated_at: Optional[str] = None
    test_cases: List[FrontendTestCase]
    metadata: Optional[Dict[str, Any]] = None


# ============================================================================
#  FRONTEND REQUEST SCHEMA
# ============================================================================

class TaskInfo(BaseModel):
    """Task information from frontend"""
    id: int
    taskCode: Optional[str] = None
    title: str
    description: Optional[str] = None
    status: Optional[str] = None
    assignedTo: Optional[int] = None


class FrontendGenerateRequest(BaseModel):
    """
    Request format from frontend for feature-based test case generation.
    
    All dynamic data comes from the frontend's current state (issue-detail page).
    """
    # Authentication (optional - can use session token)
    credentials: Optional[Credentials] = None
    session_token: Optional[str] = Field(None, description="PM Tool session token")
    
    # Feature Context (from issue state)
    feature_id: int = Field(..., description="Feature/Issue ID (required)")
    feature_title: Optional[str] = None
    feature_description: Optional[str] = None
    
    # Project Context
    project_id: Optional[int] = None
    project_name: Optional[str] = None
    
    # Deliverable Context
    deliverable_id: Optional[int] = None
    deliverable_name: Optional[str] = None
    
    # Tasks to generate test cases for
    tasks: List[TaskInfo] = Field(default=[], description="Tasks inside this feature")
    
    # Existing test cases to avoid duplicates
    existing_test_cases: Optional[List[Dict[str, str]]] = Field(
        default=None, 
        description="Existing test cases (title, description) to avoid generating duplicates"
    )
    
    # Additional context from user (text or extracted PDF content)
    additional_context: Optional[str] = Field(
        default=None,
        description="Additional context provided by user (text or PDF content) to enhance test case generation"
    )
    
    # Generation Options
    test_case_count: int = Field(default=3, ge=1, le=10, description="Test cases per task")
    environment: str = Field(default="Staging", description="Test environment")
    include_attachments: bool = Field(default=True, description="Include document context")
    
    # AI Settings
    groq_model: Optional[str] = Field(None, description="Override default model")
    temperature: Optional[float] = Field(None, ge=0, le=1, description="Override temperature")
    
    @validator('environment')
    def validate_environment(cls, v):
        valid = ['Development', 'Testing', 'Staging', 'Production']
        if v not in valid:
            return 'Staging'
        return v


class HealthResponse(BaseModel):
    status: str
    timestamp: str
    version: str
    groq_status: str
    pm_tool_status: str


class ErrorResponse(BaseModel):
    error: str
    message: str
    details: Optional[Dict[str, Any]] = None
    timestamp: str