# app/models/syndarix/issue.py
"""
Issue model for Syndarix AI consulting platform.

An Issue represents a unit of work that can be assigned to agents or humans,
with optional synchronization to external issue trackers (Gitea, GitHub, GitLab).
"""

from sqlalchemy import Column, DateTime, Enum, ForeignKey, Index, Integer, String, Text
from sqlalchemy.dialects.postgresql import (
    JSONB,
    UUID as PGUUID,
)
from sqlalchemy.orm import relationship

from app.models.base import Base, TimestampMixin, UUIDMixin

from .enums import IssuePriority, IssueStatus, SyncStatus


class Issue(Base, UUIDMixin, TimestampMixin):
    """
    Issue model representing a unit of work in a project.

    Features:
    - Standard issue fields (title, body, status, priority)
    - Assignment to agent instances or human assignees
    - Sprint association for backlog management
    - External tracker synchronization (Gitea, GitHub, GitLab)
    """

    __tablename__ = "issues"

    # Foreign key to project
    project_id = Column(
        PGUUID(as_uuid=True),
        ForeignKey("projects.id", ondelete="CASCADE"),
        nullable=False,
        index=True,
    )

    # Issue content
    title = Column(String(500), nullable=False)
    body = Column(Text, nullable=False, default="")

    # Status and priority
    status: Column[IssueStatus] = Column(
        Enum(IssueStatus),
        default=IssueStatus.OPEN,
        nullable=False,
        index=True,
    )

    priority: Column[IssuePriority] = Column(
        Enum(IssuePriority),
        default=IssuePriority.MEDIUM,
        nullable=False,
        index=True,
    )

    # Labels for categorization (e.g., ["bug", "frontend", "urgent"])
    labels = Column(JSONB, default=list, nullable=False)

    # Assignment - either to an agent or a human (mutually exclusive)
    assigned_agent_id = Column(
        PGUUID(as_uuid=True),
        ForeignKey("agent_instances.id", ondelete="SET NULL"),
        nullable=True,
        index=True,
    )

    # Human assignee (username or email, not a FK to allow external users)
    human_assignee = Column(String(255), nullable=True, index=True)

    # Sprint association
    sprint_id = Column(
        PGUUID(as_uuid=True),
        ForeignKey("sprints.id", ondelete="SET NULL"),
        nullable=True,
        index=True,
    )

    # Story points for estimation
    story_points = Column(Integer, nullable=True)

    # External tracker integration
    external_tracker = Column(
        String(50),
        nullable=True,
        index=True,
    )  # 'gitea', 'github', 'gitlab'

    external_id = Column(String(255), nullable=True)  # External system's ID
    external_url = Column(String(1000), nullable=True)  # Link to external issue
    external_number = Column(Integer, nullable=True)  # Issue number (e.g., #123)

    # Sync status with external tracker
    sync_status: Column[SyncStatus] = Column(
        Enum(SyncStatus),
        default=SyncStatus.SYNCED,
        nullable=False,
        # Note: Index defined in __table_args__ as ix_issues_sync_status
    )

    last_synced_at = Column(DateTime(timezone=True), nullable=True)
    external_updated_at = Column(DateTime(timezone=True), nullable=True)

    # Lifecycle timestamp
    closed_at = Column(DateTime(timezone=True), nullable=True, index=True)

    # Relationships
    project = relationship("Project", back_populates="issues")
    assigned_agent = relationship(
        "AgentInstance",
        back_populates="assigned_issues",
        foreign_keys=[assigned_agent_id],
    )
    sprint = relationship("Sprint", back_populates="issues")

    __table_args__ = (
        Index("ix_issues_project_status", "project_id", "status"),
        Index("ix_issues_project_priority", "project_id", "priority"),
        Index("ix_issues_project_sprint", "project_id", "sprint_id"),
        Index("ix_issues_external_tracker_id", "external_tracker", "external_id"),
        Index("ix_issues_sync_status", "sync_status"),
        Index("ix_issues_project_agent", "project_id", "assigned_agent_id"),
    )

    def __repr__(self) -> str:
        return (
            f"<Issue {self.id} title='{self.title[:30]}...' "
            f"status={self.status.value} priority={self.priority.value}>"
        )