from typing import Optional, List
from datetime import datetime
from pydantic import BaseModel, SecretStr


class TokenRequest(BaseModel):
    username: str
    password: SecretStr


class TokenResponse(BaseModel):
    access_token: str
    token_type: str = "bearer"


class UserInfo(BaseModel):
    sub: Optional[str] = None  # Keycloak subject ID
    preferred_username: str
    email: Optional[str] = None
    full_name: Optional[str] = None
    db_user_id: Optional[int] = None  # Database user ID (populated after login)
    role: Optional[str] = None  # User role name
    role_id: Optional[int] = None  # User role ID (1=editor, 2=auditor, 3=admin)


# Role schemas
ROLE_DISPLAY_NAMES = {
    "editor": "Editor",
    "auditor": "Auditor", 
    "admin": "Project Admin"
}


class RoleResponse(BaseModel):
    """Response schema for a role."""
    id: int
    role_name: str
    display_name: str

    class Config:
        from_attributes = True

    @classmethod
    def from_role(cls, role) -> "RoleResponse":
        """Create a RoleResponse from a Role model."""
        return cls(
            id=role.id,
            role_name=role.role_name,
            display_name=ROLE_DISPLAY_NAMES.get(role.role_name, role.role_name.title())
        )


class ProjectMemberResponse(BaseModel):
    """Response schema for a project member with role info."""
    id: int
    sub: str
    role_id: int
    role_name: str
    role_display_name: str
    created_at: Optional[datetime] = None

    class Config:
        from_attributes = True


class UserRoleUpdateRequest(BaseModel):
    """Request schema for updating a user's role."""
    role_id: int


# Project schemas
class ProjectBase(BaseModel):
    """Base schema for projects."""
    project_name: str
    project_desc: Optional[str] = None


class ProjectResponse(BaseModel):
    """Response schema for a single project."""
    id: int
    project_name: str
    project_desc: Optional[str] = None
    created_at: Optional[datetime] = None

    class Config:
        from_attributes = True


class ProjectCreateRequest(BaseModel):
    """Request schema for creating a project."""
    project_name: str
    project_desc: Optional[str] = None


class ProjectUpdateRequest(BaseModel):
    """Request schema for updating a project."""
    project_name: Optional[str] = None
    project_desc: Optional[str] = None


class ProjectListResponse(BaseModel):
    """Response schema for list of projects."""
    projects: List[ProjectResponse]


class ProjectMemberRequest(BaseModel):
    """Request schema for adding/removing project members."""
    user_id: int


# Group schemas
class GroupResponse(BaseModel):
    """Response schema for a single group."""
    id: int
    group_name: str
    hex_color: str

    class Config:
        from_attributes = True


class GroupListResponse(BaseModel):
    """Response schema for list of groups."""
    groups: List[GroupResponse]


# Tag schemas
class TagResponse(BaseModel):
    """Response schema for a single tag."""
    id: int
    tag_code: str
    tag_description: str

    class Config:
        from_attributes = True


class TagListResponse(BaseModel):
    """Response schema for list of tags."""
    tags: List[TagResponse]


# Priority schemas
class PriorityResponse(BaseModel):
    """Response schema for a priority."""
    id: int
    priority_name: str
    priority_num: int

    class Config:
        from_attributes = True


# Requirement Status schemas
class RequirementStatusResponse(BaseModel):
    """Response schema for a requirement lifecycle status."""
    id: int
    status_code: str
    status_name: str
    description: Optional[str] = None

    class Config:
        from_attributes = True


# Validation schemas
class ValidationStatusResponse(BaseModel):
    """Response schema for a validation status."""
    id: int
    status_name: str

    class Config:
        from_attributes = True


class ValidationResponse(BaseModel):
    """Response schema for a validation."""
    id: int
    status_name: str
    req_version_snapshot: int
    comment: Optional[str] = None
    created_at: Optional[datetime] = None

    class Config:
        from_attributes = True


class ValidationHistoryResponse(BaseModel):
    """Response schema for validation history with validator info."""
    id: int
    status_name: str
    status_id: int
    req_version_snapshot: int
    comment: Optional[str] = None
    created_at: Optional[datetime] = None
    validator_username: str
    validator_id: int

    class Config:
        from_attributes = True


class ValidationCreateRequest(BaseModel):
    """Request schema for creating a validation."""
    status_id: int
    comment: Optional[str] = None


# Requirement schemas
class RequirementResponse(BaseModel):
    """Response schema for a single requirement."""
    id: int
    project_id: int
    req_name: str
    req_desc: Optional[str] = None
    version: int
    created_at: Optional[datetime] = None
    updated_at: Optional[datetime] = None
    tag: TagResponse
    priority: Optional[PriorityResponse] = None
    groups: List[GroupResponse] = []
    # Requirement lifecycle status (Draft, Regular)
    status: Optional[RequirementStatusResponse] = None
    # Validation status (Approved, Denied, etc.)
    validation_status: Optional[str] = None  # Computed from latest validation
    validated_by: Optional[str] = None  # Username of the validator
    validated_at: Optional[datetime] = None  # When the latest validation was made
    validation_version: Optional[int] = None  # Version at which requirement was validated
    author_username: Optional[str] = None  # Display name of who created the requirement
    last_editor_username: Optional[str] = None  # Display name of who last edited the requirement

    class Config:
        from_attributes = True


class RequirementListResponse(BaseModel):
    """Response schema for list of requirements."""
    requirements: List[RequirementResponse]


class RequirementCreateRequest(BaseModel):
    """Request schema for creating a requirement."""
    project_id: int
    tag_id: int
    req_name: str
    req_desc: Optional[str] = None
    priority_id: Optional[int] = None
    group_ids: Optional[List[int]] = None
    status_id: Optional[int] = None  # Defaults to Draft (1) if not provided


class RequirementUpdateRequest(BaseModel):
    """Request schema for updating a requirement."""
    req_name: Optional[str] = None
    req_desc: Optional[str] = None
    tag_id: Optional[int] = None
    priority_id: Optional[int] = None
    group_ids: Optional[List[int]] = None
    status_id: Optional[int] = None


class RequirementHistoryResponse(BaseModel):
    """Response schema for requirement history (previous versions)."""
    history_id: int
    version: Optional[int] = None
    req_name: Optional[str] = None
    req_desc: Optional[str] = None
    tag_code: Optional[str] = None
    priority_name: Optional[str] = None
    edited_by_username: Optional[str] = None
    valid_from: Optional[datetime] = None
    valid_to: Optional[datetime] = None

    class Config:
        from_attributes = True


# Relationship Type schemas
class RelationshipTypeResponse(BaseModel):
    """Response schema for a relationship type."""
    id: int
    project_id: int
    type_name: str
    type_description: Optional[str] = None
    inverse_type_name: Optional[str] = None

    class Config:
        from_attributes = True


class RelationshipTypeCreateRequest(BaseModel):
    """Request schema for creating a relationship type."""
    type_name: str
    type_description: Optional[str] = None
    inverse_type_name: Optional[str] = None


class RelationshipTypeUpdateRequest(BaseModel):
    """Request schema for updating a relationship type."""
    type_name: Optional[str] = None
    type_description: Optional[str] = None
    inverse_type_name: Optional[str] = None


# Requirement Link schemas
class LinkedRequirementInfo(BaseModel):
    """Brief info about a linked requirement."""
    id: int
    req_name: str
    tag_code: str

    class Config:
        from_attributes = True


class RequirementLinkResponse(BaseModel):
    """Response schema for a requirement link with direction."""
    id: int
    direction: str  # 'outgoing' or 'incoming'
    type_name: str
    type_id: int
    inverse_type_name: Optional[str] = None
    linked_requirement: LinkedRequirementInfo
    created_by_username: Optional[str] = None
    created_by_id: Optional[int] = None
    created_at: Optional[datetime] = None

    class Config:
        from_attributes = True


class RequirementLinkCreateRequest(BaseModel):
    """Request schema for creating a requirement link."""
    relationship_type_id: int
    target_requirement_id: int


# Requirement Search schemas
class RequirementSearchResult(BaseModel):
    """Response schema for requirement search results (for autocomplete)."""
    id: int
    req_name: str
    tag_code: str

    class Config:
        from_attributes = True


# Comment schemas
class CommentReplyResponse(BaseModel):
    """Response schema for a comment reply."""
    id: int
    reply_text: str
    created_at: Optional[datetime] = None
    updated_at: Optional[datetime] = None
    author_id: Optional[int] = None
    author_username: Optional[str] = None
    author_full_name: Optional[str] = None
    author_role: Optional[str] = None

    class Config:
        from_attributes = True


class CommentResponse(BaseModel):
    """Response schema for a comment with its replies."""
    id: int
    comment_text: str
    created_at: Optional[datetime] = None
    updated_at: Optional[datetime] = None
    author_id: Optional[int] = None
    author_username: Optional[str] = None
    author_full_name: Optional[str] = None
    author_role: Optional[str] = None
    replies: List[CommentReplyResponse] = []

    class Config:
        from_attributes = True


class CommentCreateRequest(BaseModel):
    """Request schema for creating a comment."""
    comment_text: str


class ReplyCreateRequest(BaseModel):
    """Request schema for creating a reply."""
    reply_text: str