package database

import (
	"crowsnest/internal/model"
	"database/sql"
	"net/url"
	"strings"
)

type ArticleRepository struct {
	DB *sql.DB
}

// Gets all the article objects from the database. This may throw an error if
// the connection to the database fails.
func (m *ArticleRepository) All(limit int, offset int) ([]model.Article, error) {
	stmt := `
        SELECT id, title, sourceUrl, content, publishDate, fetchDate
        FROM articles 
        ORDER BY publishDate DESC
		LIMIT $1 OFFSET $2
    `
	rows, err := m.DB.Query(stmt, limit, offset)
	if err != nil {
		return nil, err
	}

	articles := []model.Article{}
	for rows.Next() {
		a := model.Article{}
		err := rows.Scan(&a.Id, &a.Title, &a.SourceUrl, &a.Content, &a.PublishDate, &a.FetchDate)
		if err != nil {
			return nil, err
		}

		articles = append(articles, a)
	}

	if err = rows.Err(); err != nil {
		return nil, err
	}

	return articles, nil
}

func (m *ArticleRepository) AllArticleViewModels(limit int, offset int) ([]*model.ArticleViewModel, error) {
	stmt := `
        SELECT a.id, a.title, a.sourceUrl, a.publishDate, d.summary
        FROM articles a JOIN documents d ON a.document_id = d.id
        ORDER BY a.publishDate DESC
		LIMIT $1 OFFSET $2
    `
	rows, err := m.DB.Query(stmt, limit, offset)
	if err != nil {
		return nil, err
	}

	articleVMs := []*model.ArticleViewModel{}
    var sourceUrl string
	for rows.Next() {
		a := model.ArticleViewModel{}

		err := rows.Scan(&a.Id, &a.Title, &sourceUrl, &a.PublishDate, &a.Summary)
		if err != nil {
			return nil, err
		}

        // summary
        if a.Summary == "" {
            a.Summary = "N/A"
        }

        // short url
	    parsedURL, err := url.Parse(sourceUrl)
	    if err == nil {
	    	a.ShortSource = parsedURL.Hostname()
	    } else {
            a.ShortSource = ""
        }
        
        // ai summary always false
        a.AiSummarized = false

		articleVMs = append(articleVMs, &a)
	}

	if err = rows.Err(); err != nil {
		return nil, err
	}

	return articleVMs, nil

}

// Counts all articles in the database. This may throw an error if the
// connection to the database fails.
func (m *ArticleRepository) CountAll() (uint, error) {
	stmt := `SELECT count(id) FROM articles `

	rows := m.DB.QueryRow(stmt)

	count := uint(0)
	if err := rows.Scan(&count); err != nil {
		return 0, err
	}

	return count, nil
}

// Will use the full-text search features of the underlying database to search
// articles for a given search query. This may fail if the connection to the
// database fails.
func (m *ArticleRepository) SearchArticleViewModel(query string) ([]*model.ArticleViewModel, error) {
	stmt := `
        SELECT a.id, a.title, a.sourceUrl, a.publishDate, d.summary
		FROM articles a JOIN documents d ON a.document_id = d.id
		WHERE to_tsvector('german', d.content) @@ to_tsquery('german', $1)
		ORDER BY ts_rank(to_tsvector('german', d.content), to_tsquery('german', $1)) DESC
		LIMIT 10
	`

	query = strings.Join(strings.Split(strings.TrimSpace(query), " "), " | ")
	rows, err := m.DB.Query(stmt, query)
	if err != nil {
		return nil, err
	}

	articleVMs := []*model.ArticleViewModel{}
	for rows.Next() {
		a := &model.ArticleViewModel{}
        var sourceUrl string
		err := rows.Scan(&a.Id, &a.Title, &sourceUrl, &a.PublishDate, &a.Summary)
		if err != nil {
			return nil, err
		}
        // summary
        if a.Summary == "" {
            a.Summary = "N/A"
        }

        // short url
	    parsedURL, err := url.Parse(sourceUrl)
	    if err == nil {
	    	a.ShortSource = parsedURL.Hostname()
	    } else {
            a.ShortSource = ""
        }
        
        // ai summary always false
        a.AiSummarized = false

		articleVMs = append(articleVMs, a)
	}

	if err = rows.Err(); err != nil {
		return nil, err
	}
	return articleVMs, nil
}

// Will use the full-text search features of the underlying database to search
// articles for a given search query. This may fail if the connection to the
// database fails.
func (m *ArticleRepository) Search(query string) ([]model.Article, error) {
	stmt := `
		SELECT a.id, a.title, a.sourceurl, a.content, a.publishdate, a.fetchDate
		FROM articles a JOIN documents d ON a.document_id = d.id
		WHERE to_tsvector('german', d.content) @@ to_tsquery('german', $1)
		ORDER BY ts_rank(to_tsvector('german', d.content), to_tsquery('german', $1)) DESC
		LIMIT 10
	`

	query = strings.Join(strings.Split(strings.TrimSpace(query), " "), " | ")
	rows, err := m.DB.Query(stmt, query)
	if err != nil {
		return nil, err
	}

	articles := []model.Article{}
	for rows.Next() {
		a := model.Article{}
		err := rows.Scan(&a.Id, &a.Title, &a.SourceUrl, &a.Content, &a.PublishDate, &a.FetchDate)
		if err != nil {
			return nil, err
		}

		articles = append(articles, a)
	}

	if err = rows.Err(); err != nil {
		return nil, err
	}
	return articles, nil
}

// Will return an article given an id. This may fail if the connection to the
// database fails or there is no aritcle with the given id.
func (m *ArticleRepository) ById(id int) (*model.Article, error) {
	stmt := `
		SELECT a.id, a.title, a.sourceurl, a.content, a.publishdate, a.fetchDate
		FROM articles a
		WHERE a.id = $1
	`

	rows := m.DB.QueryRow(stmt, id)

	a := &model.Article{}
	if err := rows.Scan(&a.Id, &a.Title, &a.SourceUrl, &a.Content, &a.PublishDate, &a.FetchDate); err != nil {
		return nil, err
	}

	return a, nil
}

// Inserts a new article into the database. The id attribute of the given
// article will be ignored. May throw an error if the execution of the database
// query fails.
func (m *ArticleRepository) Insert(a *model.Article) error {
	// insert article
	stmt := `INSERT INTO articles (title, sourceUrl, content, publishDate, fetchDate)
             VALUES ($1, $2, $3, $4, $5, $6)
    `
	_, err := m.DB.Exec(stmt, a.Title, a.SourceUrl, a.Content, a.PublishDate, a.FetchDate)
	return err
}

func (m *ArticleRepository) Update(a *model.Article) error {
	stmt := `UPDATE articles 
             SET title = $1, sourceUrl = $2, content = $4, publishDate = $5, fetchDate = $6
             WHERE id = $8
    `
	_, err := m.DB.Exec(stmt, a.Title, a.SourceUrl, a.Content, a.PublishDate, a.FetchDate, a.Id)
	return err
}