package httpapi

import (
	"context"

	"github.com/dtoro/oikos/internal/httpapi/gen"
)

func (s *Server) SearchKnowledge(ctx context.Context, request gen.SearchKnowledgeRequestObject) (gen.SearchKnowledgeResponseObject, error) {
	q := request.Params.Q
	limit := clampLimit(request.Params.Limit)

	rows, err := s.pool.Query(ctx, `
		SELECT e.slug, COALESCE(et.name,''), ke.title, ke.source, ke.tags,
		       ts_rank(ke.search, plainto_tsquery('english', $1)) AS rank,
		       ts_headline('english', ke.content, plainto_tsquery('english', $1),
		         'MaxWords=40, MinWords=15, ShortWord=3, MaxFragments=3,
		          FragmentDelimiter=" ... "') AS snippet
		FROM knowledge_entities ke
		JOIN entities e ON e.id = ke.entity_id
		JOIN entity_types et ON et.name = e.type
		WHERE ke.search @@ plainto_tsquery('english', $1)
		ORDER BY rank DESC
		LIMIT $2`,
		q, limit)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	items := []gen.KnowledgeHit{}

	for rows.Next() {
		var slug, eType, title, source string
		var tags []string
		var rank float32
		var snippet *string

		if err := rows.Scan(&slug, &eType, &title, &source, &tags, &rank, &snippet); err != nil {
			return nil, err
		}

		hitType := gen.Document
		switch eType {
		case "investigation":
			hitType = gen.Investigation
		case "runbook":
			hitType = gen.Runbook
		}

		items = append(items, gen.KnowledgeHit{
			Slug:       slug,
			Title:      title,
			Type:       hitType,
			Rank:       &rank,
			Snippet:    snippet,
			SourcePath: &source,
		})
	}
	if rows.Err() != nil {
		return nil, rows.Err()
	}

	if items == nil {
		items = []gen.KnowledgeHit{}
	}

	return gen.SearchKnowledge200JSONResponse{Items: items}, nil
}

func (s *Server) GetEntityKnowledge(ctx context.Context, request gen.GetEntityKnowledgeRequestObject) (gen.GetEntityKnowledgeResponseObject, error) {
	entitySlug := request.EntityId

	rows, err := s.pool.Query(ctx, `
		SELECT e.slug, COALESCE(et.name,''), ke.title, ke.source, ke.tags
		FROM knowledge_entities ke
		JOIN entities e ON e.id = ke.entity_id
		JOIN entity_types et ON et.name = e.type
		JOIN relationships r ON r.source_id = ke.entity_id
		JOIN entities target ON target.id = r.target_id
		WHERE target.slug = $1
		  AND r.valid_to IS NULL
		  AND r.type IN ('documents', 'about')
		UNION
		SELECT e.slug, COALESCE(et.name,''), ke.title, ke.source, ke.tags
		FROM knowledge_entities ke
		JOIN entities e ON e.id = ke.entity_id
		JOIN entity_types et ON et.name = e.type
		JOIN relationships r ON r.source_id = ke.entity_id
		JOIN entity_types target_type ON target_type.name = r.target_id::text
		JOIN entities ent ON ent.type = target_type.name AND ent.slug = $1
		WHERE r.valid_to IS NULL
		  AND r.type = 'procedure-for'
		ORDER BY 1`,
		entitySlug)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	items := []gen.KnowledgeHit{}
	for rows.Next() {
		var slug, eType, title, source string
		var tags []string

		if err := rows.Scan(&slug, &eType, &title, &source, &tags); err != nil {
			return nil, err
		}

		hitType := gen.Document
		switch eType {
		case "investigation":
			hitType = gen.Investigation
		case "runbook":
			hitType = gen.Runbook
		}

		items = append(items, gen.KnowledgeHit{
			Slug:       slug,
			Title:      title,
			Type:       hitType,
			SourcePath: &source,
		})
	}
	if rows.Err() != nil {
		return nil, rows.Err()
	}

	if items == nil {
		items = []gen.KnowledgeHit{}
	}

	return gen.GetEntityKnowledge200JSONResponse{Items: items}, nil
}