"""Wiki-link generation from detected entities.

Converts entity references to SilverBullet-compatible wiki-links:
  - Person → [[people/firstname-lastname]]
  - Project → [[projects/project-slug]]

Only the first occurrence of each entity is linked; subsequent mentions remain plain text.
"""

import logging

from slugify import slugify

from ingestion.enrichment.models import Entity

logger = logging.getLogger(__name__)


def _entity_to_wikilink(entity: Entity) -> str:
    """Convert an entity to its wiki-link representation."""
    slug = slugify(entity.value)
    if entity.type == "person":
        return f"[[people/{slug}]]"
    elif entity.type == "project":
        return f"[[projects/{slug}]]"
    return ""


def generate_wiki_links(text: str, entities: list[Entity]) -> str:
    """Insert wiki-links into text for person and project entities.

    Only the first occurrence of each entity's value is converted to a wiki-link.
    Dates and action_items are skipped (handled by frontmatter/renderer).

    Args:
        text: The document body text.
        entities: List of detected entities from enrichment.

    Returns:
        Text with wiki-links inserted at first occurrence of each entity.
    """
    # Filter to linkable entity types
    linkable = [e for e in entities if e.type in ("person", "project")]

    # Track which entity values we've already linked (case-insensitive)
    linked_values: set[str] = set()

    for entity in linkable:
        lower_val = entity.value.lower()
        if lower_val in linked_values:
            continue

        # Find first occurrence and replace it
        idx = text.find(entity.value)
        if idx == -1:
            # Try case-insensitive search
            idx = text.lower().find(lower_val)
            if idx == -1:
                continue
            # Use the actual text at that position for replacement
            original_text = text[idx : idx + len(entity.value)]
        else:
            original_text = entity.value

        wikilink = _entity_to_wikilink(entity)
        if wikilink:
            # Replace only the first occurrence
            text = text[:idx] + wikilink + text[idx + len(original_text) :]
            linked_values.add(lower_val)

    return text