package handlers

import (
	"net/http"
	"regexp"
	"strings"
	"time"

	"github.com/gin-contrib/sessions"
	"github.com/gin-gonic/gin"
	"go_blog/models"

	"gorm.io/gorm"
)

// slugRe matches characters that are not URL-safe.
var slugRe = regexp.MustCompile(`[^a-z0-9\-]+`)

// generateSlug converts a title into a URL-friendly slug.
func generateSlug(title string) string {
	s := strings.ToLower(title)
	s = strings.ReplaceAll(s, " ", "-")
	s = slugRe.ReplaceAllString(s, "")
	s = strings.Trim(s, "-")
	// Collapse multiple dashes.
	s = regexp.MustCompile(`-{2,}`).ReplaceAllString(s, "-")
	return s
}

// ArticleCreatePage renders the article creation form.
func ArticleCreatePage(db *gorm.DB) gin.HandlerFunc {
	return func(c *gin.Context) {
		tr := getTr(c)
		data := DefaultData(c)
		data["Title"] = tr["article_create_title"]
		c.HTML(http.StatusOK, "article_create", data)
	}
}

// ArticleCreate handles the POST request to create a new article.
func ArticleCreate(db *gorm.DB) gin.HandlerFunc {
	return func(c *gin.Context) {
		tr := getTr(c)

		title := strings.TrimSpace(c.PostForm("title"))
		content := strings.TrimSpace(c.PostForm("content"))
		slug := strings.TrimSpace(c.PostForm("slug"))
		summary := strings.TrimSpace(c.PostForm("summary"))
		cover := strings.TrimSpace(c.PostForm("cover"))
		statusStr := c.PostForm("status")
		isTop := c.PostForm("is_top") == "1"

		// Validate required fields.
		if title == "" {
			data := DefaultData(c)
			data["Title"] = tr["article_create_title"]
			data["Error"] = tr["article_title_required"]
			data["FormTitle"] = title
			data["FormSlug"] = slug
			data["FormSummary"] = summary
			data["FormContent"] = content
			data["FormCover"] = cover
			data["FormStatus"] = statusStr
			c.HTML(http.StatusOK, "article_create", data)
			return
		}
		if content == "" {
			data := DefaultData(c)
			data["Title"] = tr["article_create_title"]
			data["Error"] = tr["article_content_required"]
			data["FormTitle"] = title
			data["FormSlug"] = slug
			data["FormSummary"] = summary
			data["FormContent"] = content
			data["FormCover"] = cover
			data["FormStatus"] = statusStr
			c.HTML(http.StatusOK, "article_create", data)
			return
		}

		// Auto-generate slug if empty.
		if slug == "" {
			slug = generateSlug(title)
		}

		// Parse status: default to draft (0).
		status := models.ArticleDraft
		if statusStr == "1" {
			status = models.ArticlePublished
		}

		// Get author ID from session.
		session := sessions.Default(c)
		userID := session.Get("user_id")
		if userID == nil {
			c.Redirect(http.StatusFound, "/login")
			return
		}

		// The session stores user.ID, which is a gorm uint — but be defensive
		// across int / uint / int64 storage so a type mismatch never panics.
		var authorID uint
		switch v := userID.(type) {
		case uint:
			authorID = v
		case int:
			authorID = uint(v)
		case int64:
			authorID = uint(v)
		case float64:
			authorID = uint(v)
		default:
			c.Redirect(http.StatusFound, "/login")
			return
		}

		var publishedAt *time.Time
		if status == models.ArticlePublished {
			now := time.Now()
			publishedAt = &now
		}

		article := models.Article{
			AuthorID:    authorID,
			Title:       title,
			Slug:        slug,
			Summary:     summary,
			Content:     content,
			Cover:       cover,
			Status:      status,
			IsTop:       isTop,
			PublishedAt: publishedAt,
		}

		if err := db.Create(&article).Error; err != nil {
			data := DefaultData(c)
			data["Title"] = tr["article_create_title"]
			data["Error"] = tr["article_error"]
			data["FormTitle"] = title
			data["FormSlug"] = slug
			data["FormSummary"] = summary
			data["FormContent"] = content
			data["FormCover"] = cover
			data["FormStatus"] = statusStr
			c.HTML(http.StatusOK, "article_create", data)
			return
		}

		// Success: redirect to dashboard.
		c.Redirect(http.StatusFound, "/admin")
	}
}