package news

import (
	"fmt"
	"time"

	"dk/internal/database"

	"zombiezen.com/go/sqlite"
)

// News represents a news post in the database
type News struct {
	ID      int    `json:"id"`
	Author  int    `json:"author"`
	Posted  int64  `json:"posted"`
	Content string `json:"content"`

	db *database.DB
}

// Find retrieves a news post by ID
func Find(db *database.DB, id int) (*News, error) {
	news := &News{db: db}

	query := "SELECT id, author, posted, content FROM news WHERE id = ?"
	err := db.Query(query, func(stmt *sqlite.Stmt) error {
		news.ID = stmt.ColumnInt(0)
		news.Author = stmt.ColumnInt(1)
		news.Posted = stmt.ColumnInt64(2)
		news.Content = stmt.ColumnText(3)
		return nil
	}, id)

	if err != nil {
		return nil, fmt.Errorf("failed to find news: %w", err)
	}

	if news.ID == 0 {
		return nil, fmt.Errorf("news with ID %d not found", id)
	}

	return news, nil
}

// All retrieves all news posts ordered by posted date (newest first)
func All(db *database.DB) ([]*News, error) {
	var newsPosts []*News

	query := "SELECT id, author, posted, content FROM news ORDER BY posted DESC, id DESC"
	err := db.Query(query, func(stmt *sqlite.Stmt) error {
		news := &News{
			ID:      stmt.ColumnInt(0),
			Author:  stmt.ColumnInt(1),
			Posted:  stmt.ColumnInt64(2),
			Content: stmt.ColumnText(3),
			db:      db,
		}
		newsPosts = append(newsPosts, news)
		return nil
	})

	if err != nil {
		return nil, fmt.Errorf("failed to retrieve all news: %w", err)
	}

	return newsPosts, nil
}

// ByAuthor retrieves news posts by a specific author
func ByAuthor(db *database.DB, authorID int) ([]*News, error) {
	var newsPosts []*News

	query := "SELECT id, author, posted, content FROM news WHERE author = ? ORDER BY posted DESC, id DESC"
	err := db.Query(query, func(stmt *sqlite.Stmt) error {
		news := &News{
			ID:      stmt.ColumnInt(0),
			Author:  stmt.ColumnInt(1),
			Posted:  stmt.ColumnInt64(2),
			Content: stmt.ColumnText(3),
			db:      db,
		}
		newsPosts = append(newsPosts, news)
		return nil
	}, authorID)

	if err != nil {
		return nil, fmt.Errorf("failed to retrieve news by author: %w", err)
	}

	return newsPosts, nil
}

// Recent retrieves the most recent news posts (limited by count)
func Recent(db *database.DB, limit int) ([]*News, error) {
	var newsPosts []*News

	query := "SELECT id, author, posted, content FROM news ORDER BY posted DESC, id DESC LIMIT ?"
	err := db.Query(query, func(stmt *sqlite.Stmt) error {
		news := &News{
			ID:      stmt.ColumnInt(0),
			Author:  stmt.ColumnInt(1),
			Posted:  stmt.ColumnInt64(2),
			Content: stmt.ColumnText(3),
			db:      db,
		}
		newsPosts = append(newsPosts, news)
		return nil
	}, limit)

	if err != nil {
		return nil, fmt.Errorf("failed to retrieve recent news: %w", err)
	}

	return newsPosts, nil
}

// Since retrieves news posts since a specific timestamp
func Since(db *database.DB, since int64) ([]*News, error) {
	var newsPosts []*News

	query := "SELECT id, author, posted, content FROM news WHERE posted >= ? ORDER BY posted DESC, id DESC"
	err := db.Query(query, func(stmt *sqlite.Stmt) error {
		news := &News{
			ID:      stmt.ColumnInt(0),
			Author:  stmt.ColumnInt(1),
			Posted:  stmt.ColumnInt64(2),
			Content: stmt.ColumnText(3),
			db:      db,
		}
		newsPosts = append(newsPosts, news)
		return nil
	}, since)

	if err != nil {
		return nil, fmt.Errorf("failed to retrieve news since timestamp: %w", err)
	}

	return newsPosts, nil
}

// Between retrieves news posts between two timestamps (inclusive)
func Between(db *database.DB, start, end int64) ([]*News, error) {
	var newsPosts []*News

	query := "SELECT id, author, posted, content FROM news WHERE posted >= ? AND posted <= ? ORDER BY posted DESC, id DESC"
	err := db.Query(query, func(stmt *sqlite.Stmt) error {
		news := &News{
			ID:      stmt.ColumnInt(0),
			Author:  stmt.ColumnInt(1),
			Posted:  stmt.ColumnInt64(2),
			Content: stmt.ColumnText(3),
			db:      db,
		}
		newsPosts = append(newsPosts, news)
		return nil
	}, start, end)

	if err != nil {
		return nil, fmt.Errorf("failed to retrieve news between timestamps: %w", err)
	}

	return newsPosts, nil
}

// Save updates an existing news post in the database
func (n *News) Save() error {
	if n.ID == 0 {
		return fmt.Errorf("cannot save news without ID")
	}

	query := `UPDATE news SET author = ?, posted = ?, content = ? WHERE id = ?`
	return n.db.Exec(query, n.Author, n.Posted, n.Content, n.ID)
}

// Delete removes the news post from the database
func (n *News) Delete() error {
	if n.ID == 0 {
		return fmt.Errorf("cannot delete news without ID")
	}

	query := "DELETE FROM news WHERE id = ?"
	return n.db.Exec(query, n.ID)
}

// PostedTime returns the posted timestamp as a time.Time
func (n *News) PostedTime() time.Time {
	return time.Unix(n.Posted, 0)
}

// SetPostedTime sets the posted timestamp from a time.Time
func (n *News) SetPostedTime(t time.Time) {
	n.Posted = t.Unix()
}

// IsRecent returns true if the news post was made within the last 24 hours
func (n *News) IsRecent() bool {
	return time.Since(n.PostedTime()) < 24*time.Hour
}

// Age returns how long ago the news post was made
func (n *News) Age() time.Duration {
	return time.Since(n.PostedTime())
}

// IsAuthor returns true if the given user ID is the author of this news post
func (n *News) IsAuthor(userID int) bool {
	return n.Author == userID
}

// Preview returns a truncated version of the content for previews
func (n *News) Preview(maxLength int) string {
	if len(n.Content) <= maxLength {
		return n.Content
	}
	
	if maxLength < 3 {
		return n.Content[:maxLength]
	}
	
	return n.Content[:maxLength-3] + "..."
}

// WordCount returns the number of words in the content
func (n *News) WordCount() int {
	if n.Content == "" {
		return 0
	}
	
	// Simple word count by splitting on spaces
	words := 0
	inWord := false
	
	for _, char := range n.Content {
		if char == ' ' || char == '\t' || char == '\n' || char == '\r' {
			if inWord {
				words++
				inWord = false
			}
		} else {
			inWord = true
		}
	}
	
	if inWord {
		words++
	}
	
	return words
}