package repository

import (
	"context"
	"database/sql"
	"encoding/json"
	"fmt"

	"git.godopu.com/lab/landing_page/backend/internal/models"
)

type HomeRepository struct {
	db *sql.DB
}

func NewHomeRepository(db *sql.DB) *HomeRepository {
	return &HomeRepository{db: db}
}

func (r *HomeRepository) GetResearchProjects(ctx context.Context) ([]models.ResearchProject, error) {
	query := `
		SELECT id, slug, title, abstract, keywords, organization, standards_org, period, funder, created_at, updated_at
		FROM research_projects
		ORDER BY id ASC
	`
	rows, err := r.db.QueryContext(ctx, query)
	if err != nil {
		return nil, fmt.Errorf("query research projects: %w", err)
	}
	defer rows.Close()

	var projects []models.ResearchProject
	for rows.Next() {
		var p models.ResearchProject
		var kwJSON string
		err := rows.Scan(
			&p.ID, &p.Slug, &p.Title, &p.Abstract, &kwJSON,
			&p.Organization, &p.StandardsOrg, &p.Period, &p.Funder,
			&p.CreatedAt, &p.UpdatedAt,
		)
		if err != nil {
			return nil, fmt.Errorf("scan research project: %w", err)
		}
		if kwJSON != "" {
			_ = json.Unmarshal([]byte(kwJSON), &p.Keywords)
		}
		if p.Keywords == nil {
			p.Keywords = []string{}
		}
		projects = append(projects, p)
	}
	if err := rows.Err(); err != nil {
		return nil, err
	}
	return projects, nil
}

func (r *HomeRepository) GetResearchAreas(ctx context.Context) ([]models.ResearchArea, error) {
	query := `
		SELECT id, name_en, name_kr, display_order
		FROM research_areas
		ORDER BY display_order ASC, id ASC
	`
	rows, err := r.db.QueryContext(ctx, query)
	if err != nil {
		return nil, fmt.Errorf("query research areas: %w", err)
	}
	defer rows.Close()

	var areas []models.ResearchArea
	for rows.Next() {
		var a models.ResearchArea
		if err := rows.Scan(&a.ID, &a.NameEn, &a.NameKr, &a.DisplayOrder); err != nil {
			return nil, fmt.Errorf("scan research area: %w", err)
		}
		areas = append(areas, a)
	}
	return areas, rows.Err()
}

func (r *HomeRepository) GetStatsSummary(ctx context.Context) (*models.StatsSummary, error) {
	var summary models.StatsSummary

	err := r.db.QueryRowContext(ctx, "SELECT COUNT(*) FROM publications WHERE category = 'intl-journal-conf'").Scan(&summary.IntlPublications)
	if err != nil {
		return nil, fmt.Errorf("count intl publications: %w", err)
	}

	err = r.db.QueryRowContext(ctx, "SELECT COUNT(*) FROM standard_documents").Scan(&summary.StandardizationDocs)
	if err != nil {
		return nil, fmt.Errorf("count standard documents: %w", err)
	}

	err = r.db.QueryRowContext(ctx, "SELECT COUNT(*) FROM patents").Scan(&summary.Patents)
	if err != nil {
		return nil, fmt.Errorf("count patents: %w", err)
	}

	return &summary, nil
}