package v1

import (
	"encoding/json"
	"errors"
	"net/http"
	"regexp"
	"strconv"
	"strings"

	"github.com/gin-gonic/gin"

	"github.com/gochat/gochat/internal/model"
	"github.com/gochat/gochat/internal/repository"
	"github.com/gochat/gochat/internal/service"
	applogger "github.com/gochat/gochat/pkg/logger"
	"github.com/gochat/gochat/pkg/pagination"
	"github.com/gochat/gochat/pkg/response"
)

// ArticleHandler handles Article CRUD and Knowledge Base endpoints.
type ArticleHandler struct {
	svc       *service.ArticleService
	portalSvc *service.PortalService
}

// PublicList returns published help-center articles for the public portal/widget views.
// GET /hc/:slug/:locale/articles.json
func (h *ArticleHandler) PublicList(c *gin.Context) {
	portal, ok := h.resolvePublicPortal(c)
	if !ok {
		return
	}

	page, perPage, offset, ok := publicArticlePagination(c)
	if !ok {
		return
	}
	locale := c.Param("locale")
	query := strings.TrimSpace(c.Query("query"))
	params := repository.ArticleSearchParams{
		PortalID:     portal.ID,
		Query:        query,
		CategorySlug: c.Param("category_slug"),
		Locale:       locale,
		Status:       string(model.ArticleStatusPublished),
		SortBy:       c.Query("sort"),
		Offset:       offset,
		Limit:        perPage,
	}

	countParams := repository.ArticleSearchParams{
		PortalID:     portal.ID,
		Query:        query,
		CategorySlug: c.Param("category_slug"),
		Locale:       locale,
		Status:       string(model.ArticleStatusPublished),
	}
	articlesCount, err := h.svc.Count(c.Request.Context(), countParams)
	if err != nil {
		applogger.L().Errorf("Public article count: %v", err)
		response.AbortWithStatusError(c, http.StatusInternalServerError, response.ErrInternal, "failed to list articles")
		return
	}
	articles, _, err := h.svc.Search(c.Request.Context(), params)
	if err != nil {
		applogger.L().Errorf("Public article list: %v", err)
		response.AbortWithStatusError(c, http.StatusInternalServerError, response.ErrInternal, "failed to list articles")
		return
	}
	for i := range articles {
		articles[i].Portal = *portal
	}

	c.JSON(http.StatusOK, gin.H{
		"payload": publicArticlePayloads(articles, portal.Slug),
		"meta":    gin.H{"articles_count": articlesCount, "current_page": page},
	})
}

// PublicSearch returns public help-center search results for the portal search page.
// GET /hc/:slug/:locale/search
func (h *ArticleHandler) PublicSearch(c *gin.Context) {
	portal, ok := h.resolvePublicPortal(c)
	if !ok {
		return
	}

	page, perPage, offset, ok := publicSearchPagination(c)
	if !ok {
		return
	}
	query := strings.TrimSpace(c.Query("query"))
	if query == "" {
		c.JSON(http.StatusOK, gin.H{"payload": []gin.H{}, "meta": gin.H{"articles_count": 0, "current_page": page}})
		return
	}

	params := repository.ArticleSearchParams{
		PortalID: portal.ID,
		Query:    query,
		Locale:   c.Param("locale"),
		Status:   string(model.ArticleStatusPublished),
		SortBy:   c.Query("sort"),
		Offset:   offset,
		Limit:    perPage,
	}
	articles, count, err := h.svc.Search(c.Request.Context(), params)
	if err != nil {
		applogger.L().Errorf("Public article search: %v", err)
		response.AbortWithStatusError(c, http.StatusInternalServerError, response.ErrInternal, "failed to search articles")
		return
	}

	c.JSON(http.StatusOK, gin.H{
		"payload": publicSearchArticlePayloads(articles, portal.Slug, query),
		"meta":    gin.H{"articles_count": count, "current_page": page},
	})
}

// PublicShow returns a public help-center article by slug.
// GET /hc/:slug/articles/:article_slug
func (h *ArticleHandler) PublicShow(c *gin.Context) {
	portal, article, ok := h.resolvePublicArticle(c)
	if !ok {
		return
	}
	article.Portal = *portal
	c.JSON(http.StatusOK, publicArticlePayload(article, portal.Slug))
}

// PublicArticle dispatches Chatwoot article, markdown, and tracking-pixel suffix paths.
func (h *ArticleHandler) PublicArticle(c *gin.Context) {
	slug := publicArticleSlugRaw(c)
	switch {
	case strings.HasSuffix(slug, ".md"):
		h.PublicMarkdown(c)
	case strings.HasSuffix(slug, ".png"):
		h.PublicTrackingPixel(c)
	default:
		h.PublicShow(c)
	}
}

// PublicMarkdown returns the raw markdown for a published public article.
// GET /hc/:slug/articles/:article_slug.md
func (h *ArticleHandler) PublicMarkdown(c *gin.Context) {
	_, article, ok := h.resolvePublicArticle(c)
	if !ok {
		return
	}
	if article.Status != string(model.ArticleStatusPublished) {
		response.AbortWithStatusError(c, http.StatusNotFound, response.ErrNotFound, "article not found")
		return
	}
	c.Data(http.StatusOK, "text/markdown; charset=utf-8", []byte(article.Content))
}

// PublicTrackingPixel increments views for published articles and serves a 1x1 PNG.
// GET /hc/:slug/articles/:article_slug.png
func (h *ArticleHandler) PublicTrackingPixel(c *gin.Context) {
	_, article, ok := h.resolvePublicArticle(c)
	if !ok {
		return
	}
	if article.Status == string(model.ArticleStatusPublished) {
		if err := h.svc.IncrementViews(c.Request.Context(), article.ID); err != nil {
			applogger.L().Warnf("Increment public article pixel views %d: %v", article.ID, err)
		}
	}
	c.Header("Cache-Control", "private, max-age=86400")
	c.Data(http.StatusOK, "image/png", publicArticleTrackingPixelPNG)
}

// NewArticleHandler creates a new ArticleHandler.
func NewArticleHandler(svc *service.ArticleService, portalSvc ...*service.PortalService) *ArticleHandler {
	h := &ArticleHandler{svc: svc}
	if len(portalSvc) > 0 {
		h.portalSvc = portalSvc[0]
	}
	return h
}

// Create creates a new article.
// POST /portals/:portal_id/articles
func (h *ArticleHandler) Create(c *gin.Context) {
	accountID := getAccountID(c)
	if accountID == 0 {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid account_id")
		return
	}
	portal, ok := h.resolvePortal(c, accountID)
	if !ok {
		return
	}

	var req service.CreateArticleRequest
	if err := bindChatwootPayload(c, "article", &req); err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrValidation, err.Error())
		return
	}

	article, err := h.svc.CreateWithAccount(c.Request.Context(), accountID, portal.ID, currentUserID(c), &req)
	if err != nil {
		applogger.L().Errorf("Create article: %v", err)
		response.AbortWithStatusError(c, http.StatusInternalServerError, response.ErrInternal, "failed to create article")
		return
	}

	c.JSON(http.StatusOK, gin.H{"payload": articlePayload(article)})
}

// Get retrieves an article by ID and increments its view count.
// GET /portals/:portal_id/articles/:id
func (h *ArticleHandler) Get(c *gin.Context) {
	portal, ok := h.resolvePortalForRequest(c)
	if !ok {
		return
	}
	id, err := articleIDParam(c)
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid article id")
		return
	}

	article, err := h.svc.GetByPortalAndID(c.Request.Context(), portal.ID, id)
	if err != nil {
		applogger.L().Errorf("Get article: %v", err)
		response.AbortWithStatusError(c, http.StatusNotFound, response.ErrNotFound, "article not found")
		return
	}

	// Increment views on each read (non-blocking; log error only)
	if err := h.svc.IncrementViews(c.Request.Context(), id); err != nil {
		applogger.L().Warnf("IncrementViews article %d: %v", id, err)
	} else {
		article.Views++
	}

	c.JSON(http.StatusOK, gin.H{"payload": articlePayload(article)})
}

// Edit retrieves an article in edit context (full content without incrementing views).
// GET /portals/:portal_id/articles/:id/edit
func (h *ArticleHandler) Edit(c *gin.Context) {
	portal, ok := h.resolvePortalForRequest(c)
	if !ok {
		return
	}
	id, err := articleIDParam(c)
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid article id")
		return
	}

	article, err := h.svc.GetByPortalAndID(c.Request.Context(), portal.ID, id)
	if err != nil {
		applogger.L().Errorf("Edit article: %v", err)
		response.AbortWithStatusError(c, http.StatusNotFound, response.ErrNotFound, "article not found")
		return
	}

	c.JSON(http.StatusOK, gin.H{"payload": articlePayload(article)})
}

// Update modifies an existing article.
// PUT /portals/:portal_id/articles/:id
func (h *ArticleHandler) Update(c *gin.Context) {
	portal, ok := h.resolvePortalForRequest(c)
	if !ok {
		return
	}
	id, err := articleIDParam(c)
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid article id")
		return
	}

	var req service.UpdateArticleRequest
	if err := bindChatwootPayload(c, "article", &req); err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrValidation, err.Error())
		return
	}

	article, err := h.svc.UpdateScoped(c.Request.Context(), portal.ID, id, &req)
	if err != nil {
		applogger.L().Errorf("Update article: %v", err)
		response.AbortWithStatusError(c, http.StatusUnprocessableEntity, response.ErrInternal, "failed to update article")
		return
	}

	c.JSON(http.StatusOK, gin.H{"payload": articlePayload(article)})
}

// Delete removes an article.
// DELETE /portals/:portal_id/articles/:id
func (h *ArticleHandler) Delete(c *gin.Context) {
	portal, ok := h.resolvePortalForRequest(c)
	if !ok {
		return
	}
	id, err := articleIDParam(c)
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid article id")
		return
	}

	if err := h.svc.DeleteScoped(c.Request.Context(), portal.ID, id); err != nil {
		applogger.L().Errorf("Delete article: %v", err)
		response.AbortWithStatusError(c, http.StatusUnprocessableEntity, response.ErrInternal, "failed to delete article")
		return
	}

	c.Status(http.StatusOK)
}

// List returns all articles for a portal (paginated).
// GET /portals/:portal_id/articles
func (h *ArticleHandler) List(c *gin.Context) {
	accountID := getAccountID(c)
	if accountID == 0 {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid account_id")
		return
	}
	portal, ok := h.resolvePortal(c, accountID)
	if !ok {
		return
	}

	p := pagination.Parse(c)
	params, ok := h.articleSearchParams(c, portal.ID, p.Offset, p.PerPage)
	if !ok {
		return
	}
	articles, _, svcErr := h.svc.Search(c.Request.Context(), params)
	if svcErr != nil {
		applogger.L().Errorf("List articles: %v", svcErr)
		response.AbortWithStatusError(c, http.StatusInternalServerError, response.ErrInternal, "failed to list articles")
		return
	}
	meta, svcErr := h.svc.ListMeta(c.Request.Context(), params, currentUserID(c))
	if svcErr != nil {
		applogger.L().Errorf("Article list meta: %v", svcErr)
		response.AbortWithStatusError(c, http.StatusInternalServerError, response.ErrInternal, "failed to list articles")
		return
	}

	c.JSON(http.StatusOK, gin.H{"payload": articlePayloads(articles), "meta": articleListMetaPayload(meta, p.Page)})
}

// ListByCategory returns articles for a specific category (paginated).
// GET /portals/:portal_id/categories/:category_id/articles
func (h *ArticleHandler) ListByCategory(c *gin.Context) {
	categoryID, err := strconv.ParseUint(c.Param("category_id"), 10, 64)
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid category_id")
		return
	}

	p := pagination.Parse(c)

	articles, count, svcErr := h.svc.ListByCategoryID(c.Request.Context(), uint(categoryID), p.Page, p.PerPage)
	if svcErr != nil {
		applogger.L().Errorf("List articles by category: %v", svcErr)
		response.AbortWithStatusError(c, http.StatusInternalServerError, response.ErrInternal, "failed to list articles")
		return
	}

	response.OKWithMeta(c, articles, p.Page, p.PerPage, count)
}

// Search returns filtered articles based on query parameters.
// GET /portals/:portal_id/articles/search
func (h *ArticleHandler) Search(c *gin.Context) {
	accountID := getAccountID(c)
	if accountID == 0 {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid account_id")
		return
	}
	portal, ok := h.resolvePortal(c, accountID)
	if !ok {
		return
	}

	p := pagination.Parse(c)
	params, ok := h.articleSearchParams(c, portal.ID, p.Offset, p.PerPage)
	if !ok {
		return
	}

	articles, count, svcErr := h.svc.Search(c.Request.Context(), params)
	if svcErr != nil {
		applogger.L().Errorf("Search articles: %v", svcErr)
		response.AbortWithStatusError(c, http.StatusInternalServerError, response.ErrInternal, "failed to search articles")
		return
	}

	meta, svcErr := h.svc.ListMeta(c.Request.Context(), params, currentUserID(c))
	if svcErr != nil {
		applogger.L().Errorf("Article search meta: %v", svcErr)
		response.AbortWithStatusError(c, http.StatusInternalServerError, response.ErrInternal, "failed to search articles")
		return
	}
	meta.ArticlesCount = count
	c.JSON(http.StatusOK, gin.H{"payload": articlePayloads(articles), "meta": articleListMetaPayload(meta, p.Page)})
}

// SemanticSearch performs AI-powered semantic search on help center articles.
// Uses LLM embeddings + pgvector cosine similarity to find articles by meaning,
// not just keyword matching.
//
// GET /portals/:portal_id/articles/semantic_search?query=how+to+reset+password
func (h *ArticleHandler) SemanticSearch(c *gin.Context) {
	accountID := getAccountID(c)
	if accountID == 0 {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid account_id")
		return
	}
	portal, ok := h.resolvePortal(c, accountID)
	if !ok {
		return
	}

	query := strings.TrimSpace(c.Query("query"))
	if query == "" {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "query parameter is required")
		return
	}

	limit := 10
	if l := c.Query("limit"); l != "" {
		if parsed, err := strconv.Atoi(l); err == nil && parsed > 0 && parsed <= 50 {
			limit = parsed
		}
	}

	articles, err := h.svc.SemanticSearch(c.Request.Context(), portal.ID, query, limit)
	if err != nil {
		applogger.L().Errorf("SemanticSearch articles: %v", err)
		response.AbortWithStatusError(c, http.StatusInternalServerError, response.ErrInternal, "failed to perform semantic search")
		return
	}

	c.JSON(http.StatusOK, gin.H{"payload": articlePayloads(articles)})
}

// StatusCounts returns article counts grouped by status.
// GET /portals/:portal_id/articles/status_counts
func (h *ArticleHandler) StatusCounts(c *gin.Context) {
	portalID, err := strconv.ParseUint(c.Param("portal_id"), 10, 64)
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid portal_id")
		return
	}

	counts, svcErr := h.svc.StatusCounts(c.Request.Context(), uint(portalID))
	if svcErr != nil {
		applogger.L().Errorf("StatusCounts: %v", svcErr)
		response.AbortWithStatusError(c, http.StatusInternalServerError, response.ErrInternal, "failed to get status counts")
		return
	}

	response.OK(c, counts)
}

// reorderRequest is the JSON payload for the Reorder endpoint.
type reorderRequest struct {
	Positions []positionEntry `json:"positions"`
}

// positionEntry maps an article ID to its new position value.
type positionEntry struct {
	ID       uint `json:"id"`
	Position int  `json:"position"`
}

// Reorder batch-updates article positions.
// POST /portals/:portal_id/articles/reorder
func (h *ArticleHandler) Reorder(c *gin.Context) {
	portal, ok := h.resolvePortalForRequest(c)
	if !ok {
		return
	}
	positions, err := bindArticleReorder(c)
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrValidation, err.Error())
		return
	}

	if err := h.svc.ReorderScoped(c.Request.Context(), portal.ID, positions); err != nil {
		applogger.L().Errorf("Reorder articles: %v", err)
		response.AbortWithStatusError(c, http.StatusInternalServerError, response.ErrInternal, "failed to reorder articles")
		return
	}

	c.Status(http.StatusOK)
}

// bulkUpdateStatusRequest is the JSON payload for BulkUpdateStatus.
type bulkUpdateStatusRequest struct {
	IDs    []uint `json:"ids"`
	Status string `json:"status"`
}

// BulkUpdateStatus updates the status of multiple articles at once.
// POST /portals/:portal_id/articles/bulk_update_status
func (h *ArticleHandler) BulkUpdateStatus(c *gin.Context) {
	portal, ok := h.resolvePortalForRequest(c)
	if !ok {
		return
	}
	var req bulkUpdateStatusRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrValidation, err.Error())
		return
	}

	if err := h.svc.BulkUpdateStatusScoped(c.Request.Context(), portal.ID, req.IDs, req.Status); err != nil {
		applogger.L().Errorf("BulkUpdateStatus articles: %v", err)
		renderArticleBulkError(c, err)
		return
	}

	c.Status(http.StatusOK)
}

type bulkUpdateCategoryRequest struct {
	IDs        []uint `json:"ids"`
	CategoryID uint   `json:"category_id"`
}

func (h *ArticleHandler) BulkUpdateCategory(c *gin.Context) {
	portal, ok := h.resolvePortalForRequest(c)
	if !ok {
		return
	}
	var req bulkUpdateCategoryRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrValidation, err.Error())
		return
	}
	if err := h.svc.BulkUpdateCategoryScoped(c.Request.Context(), portal.ID, req.IDs, req.CategoryID); err != nil {
		applogger.L().Errorf("BulkUpdateCategory articles: %v", err)
		renderArticleBulkError(c, err)
		return
	}
	c.Status(http.StatusOK)
}

// bulkDeleteRequest is the JSON payload for BulkDelete.
type bulkDeleteRequest struct {
	IDs []uint `json:"ids"`
}

// BulkDelete deletes multiple articles at once.
// POST /portals/:portal_id/articles/bulk_delete
func (h *ArticleHandler) BulkDelete(c *gin.Context) {
	portal, ok := h.resolvePortalForRequest(c)
	if !ok {
		return
	}
	var req bulkDeleteRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrValidation, err.Error())
		return
	}

	if err := h.svc.BulkDeleteScoped(c.Request.Context(), portal.ID, req.IDs); err != nil {
		applogger.L().Errorf("BulkDelete articles: %v", err)
		renderArticleBulkError(c, err)
		return
	}

	c.Status(http.StatusOK)
}

func (h *ArticleHandler) BulkTranslate(c *gin.Context) {
	portal, ok := h.resolvePortalForRequest(c)
	if !ok {
		return
	}
	var req service.BulkTranslateRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrValidation, err.Error())
		return
	}
	if err := h.svc.BulkTranslate(c.Request.Context(), portal.AccountID, portal, currentUserID(c), req); err != nil {
		var conflict *service.ArticleTranslationConflictError
		if errors.As(err, &conflict) {
			c.JSON(http.StatusConflict, gin.H{"duplicate_articles": conflict.Duplicates})
			return
		}
		renderArticleBulkError(c, err)
		return
	}
	c.Status(http.StatusOK)
}

// BulkActions performs a bulk operation (publish/archive/delete) on multiple articles.
// POST /api/v1/accounts/:account_id/portals/:portal_id/articles/bulk_actions
func (h *ArticleHandler) BulkActions(c *gin.Context) {
	var req service.BulkActionsRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrValidation, err.Error())
		return
	}

	if len(req.IDs) == 0 {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "ids must not be empty")
		return
	}

	if err := h.svc.BulkActions(c.Request.Context(), &req); err != nil {
		applogger.L().Errorf("BulkActions articles: %v", err)
		response.AbortWithStatusError(c, http.StatusInternalServerError, response.ErrInternal, "failed to perform bulk action")
		return
	}

	response.OK(c, gin.H{"action": req.Action, "ids": req.IDs})
}

func (h *ArticleHandler) resolvePortalForRequest(c *gin.Context) (*model.Portal, bool) {
	accountID := getAccountID(c)
	if accountID == 0 {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid account_id")
		return nil, false
	}
	return h.resolvePortal(c, accountID)
}

func (h *ArticleHandler) resolvePortal(c *gin.Context, accountID uint) (*model.Portal, bool) {
	if h.portalSvc != nil {
		portal, err := h.portalSvc.ResolveByAccountAndRouteID(c.Request.Context(), accountID, c.Param("portal_id"))
		if err != nil {
			response.AbortWithStatusError(c, http.StatusNotFound, response.ErrNotFound, "portal not found")
			return nil, false
		}
		return portal, true
	}
	portalID, err := strconv.ParseUint(c.Param("portal_id"), 10, 64)
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid portal_id")
		return nil, false
	}
	return &model.Portal{Base: model.Base{ID: uint(portalID)}, AccountID: accountID}, true
}

func (h *ArticleHandler) resolvePublicPortal(c *gin.Context) (*model.Portal, bool) {
	if h.portalSvc == nil {
		response.AbortWithStatusError(c, http.StatusNotFound, response.ErrNotFound, "portal not found")
		return nil, false
	}
	portal, err := h.portalSvc.ResolvePublicBySlug(c.Request.Context(), c.Param("slug"))
	if err != nil {
		response.AbortWithStatusError(c, http.StatusNotFound, response.ErrNotFound, "portal not found")
		return nil, false
	}
	return portal, true
}

func (h *ArticleHandler) resolvePublicArticle(c *gin.Context) (*model.Portal, *model.Article, bool) {
	portal, ok := h.resolvePublicPortal(c)
	if !ok {
		return nil, nil, false
	}
	slug := publicArticleSlugParam(c)
	article, err := h.svc.GetByPortalAndSlug(c.Request.Context(), portal.ID, slug)
	if err != nil {
		response.AbortWithStatusError(c, http.StatusNotFound, response.ErrNotFound, "article not found")
		return nil, nil, false
	}
	return portal, article, true
}

func publicArticleSlugParam(c *gin.Context) string {
	value := publicArticleSlugRaw(c)
	return strings.TrimSuffix(strings.TrimSuffix(value, ".md"), ".png")
}

func publicArticleSlugRaw(c *gin.Context) string {
	for _, key := range []string{"article_slug", "article_slug.md", "article_slug.png"} {
		if value := c.Param(key); value != "" {
			return value
		}
	}
	return ""
}

var publicArticleTrackingPixelPNG = []byte{
	0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a,
	0x00, 0x00, 0x00, 0x0d, 0x49, 0x48, 0x44, 0x52,
	0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x01,
	0x08, 0x06, 0x00, 0x00, 0x00, 0x1f, 0x15, 0xc4,
	0x89, 0x00, 0x00, 0x00, 0x0a, 0x49, 0x44, 0x41,
	0x54, 0x78, 0x9c, 0x63, 0x00, 0x01, 0x00, 0x00,
	0x05, 0x00, 0x01, 0x0d, 0x0a, 0x2d, 0xb4, 0x00,
	0x00, 0x00, 0x00, 0x49, 0x45, 0x4e, 0x44, 0xae,
	0x42, 0x60, 0x82,
}

func publicArticlePagination(c *gin.Context) (int, int, int, bool) {
	page := 1
	if raw := c.Query("page"); raw != "" {
		parsed, err := strconv.Atoi(raw)
		if err != nil {
			response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid page")
			return 0, 0, 0, false
		}
		if parsed > 0 {
			page = parsed
		}
	}
	perPage := 0
	if raw := c.Query("per_page"); raw != "" {
		parsed, err := strconv.Atoi(raw)
		if err != nil {
			response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid per_page")
			return 0, 0, 0, false
		}
		perPage = parsed
		if perPage < 1 {
			perPage = 25
		}
		if perPage > 100 {
			perPage = 100
		}
	}
	offset := 0
	if perPage > 0 {
		offset = (page - 1) * perPage
	}
	return page, perPage, offset, true
}

func publicSearchPagination(c *gin.Context) (int, int, int, bool) {
	page := 1
	if raw := c.Query("page"); raw != "" {
		parsed, err := strconv.Atoi(raw)
		if err != nil {
			response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid page")
			return 0, 0, 0, false
		}
		if parsed > 0 {
			page = parsed
		}
	}
	perPage := 10
	offset := (page - 1) * perPage
	return page, perPage, offset, true
}

func (h *ArticleHandler) articleSearchParams(c *gin.Context, portalID uint, offset, limit int) (repository.ArticleSearchParams, bool) {
	params := repository.ArticleSearchParams{
		PortalID:     portalID,
		Query:        c.Query("query"),
		CategorySlug: c.Query("category_slug"),
		Locale:       c.Query("locale"),
		Status:       normalizeArticleStatusFilter(c.Query("status")),
		SortBy:       c.Query("sort_by"),
		Offset:       offset,
		Limit:        limit,
	}
	if params.SortBy == "" {
		params.SortBy = c.Query("sort")
	}
	if authorIDStr := c.Query("author_id"); authorIDStr != "" {
		aid, parseErr := strconv.ParseUint(authorIDStr, 10, 64)
		if parseErr != nil {
			response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid author_id")
			return params, false
		}
		aidUint := uint(aid)
		params.AuthorID = &aidUint
	}
	return params, true
}

func normalizeArticleStatusFilter(status string) string {
	switch strings.TrimSpace(status) {
	case "0":
		return string(model.ArticleStatusDraft)
	case "1":
		return string(model.ArticleStatusPublished)
	case "2":
		return string(model.ArticleStatusArchived)
	default:
		return status
	}
}

func articleIDParam(c *gin.Context) (uint, error) {
	if id, err := parseUintAnyParam(c, "article_id", "id"); err == nil && id != 0 {
		return id, nil
	} else if err != nil {
		return 0, err
	}
	return 0, strconv.ErrSyntax
}

func bindArticleReorder(c *gin.Context) (map[uint]int, error) {
	var req struct {
		PositionsHash map[string]int  `json:"positions_hash"`
		Positions     []positionEntry `json:"positions"`
	}
	if err := c.ShouldBindJSON(&req); err != nil {
		return nil, err
	}
	positions := make(map[uint]int, len(req.PositionsHash)+len(req.Positions))
	for id, position := range req.PositionsHash {
		parsed, err := strconv.ParseUint(id, 10, 32)
		if err != nil {
			return nil, err
		}
		positions[uint(parsed)] = position
	}
	for _, entry := range req.Positions {
		positions[entry.ID] = entry.Position
	}
	return positions, nil
}

func articlePayloads(articles []model.Article) []gin.H {
	payload := make([]gin.H, 0, len(articles))
	for i := range articles {
		payload = append(payload, articlePayload(&articles[i]))
	}
	return payload
}

func articlePayload(article *model.Article) gin.H {
	if article == nil {
		return gin.H{}
	}
	payload := gin.H{
		"id":                  article.ID,
		"slug":                article.Slug,
		"title":               article.Title,
		"content":             article.Content,
		"description":         article.Description,
		"status":              article.Status,
		"position":            article.Position,
		"account_id":          article.AccountID,
		"updated_at":          article.UpdatedAt.Unix(),
		"meta":                articleMetaPayload(article.Meta),
		"category":            articleCategoryPayload(article),
		"views":               article.Views,
		"associated_articles": associatedArticlePayloads(article.AssociatedArticles),
	}
	if article.Author != nil && article.Author.ID != 0 {
		payload["author"] = serializeAgentUser(article.Author, article.AccountID, article.Author.Role, "", false, 0)
	}
	return payload
}

func articleCategoryPayload(article *model.Article) gin.H {
	payload := gin.H{"id": article.CategoryID, "name": nil, "slug": nil, "locale": nil}
	if article.Category != nil {
		payload["name"] = article.Category.Name
		payload["slug"] = article.Category.Slug
		payload["locale"] = article.Category.Locale
	}
	return payload
}

func associatedArticlePayloads(articles []model.Article) []gin.H {
	payload := make([]gin.H, 0, len(articles))
	for i := range articles {
		article := &articles[i]
		item := gin.H{
			"id":          article.ID,
			"category_id": article.CategoryID,
			"title":       article.Title,
			"content":     article.Content,
			"description": article.Description,
			"status":      article.Status,
			"account_id":  article.AccountID,
			"views":       article.Views,
		}
		if article.Portal.ID != 0 {
			item["portal"] = portalPayload(&article.Portal, article.Locale, 0)
		}
		if article.Author != nil && article.Author.ID != 0 {
			item["author"] = serializeAgentUser(article.Author, article.AccountID, article.Author.Role, "", false, 0)
		}
		payload = append(payload, item)
	}
	return payload
}

func publicArticlePayloads(articles []model.Article, portalSlug string) []gin.H {
	payload := make([]gin.H, 0, len(articles))
	for i := range articles {
		payload = append(payload, publicArticlePayload(&articles[i], portalSlug))
	}
	return payload
}

func publicArticlePayload(article *model.Article, portalSlug string) gin.H {
	if article == nil {
		return gin.H{}
	}
	if article.Portal.Slug != "" {
		portalSlug = article.Portal.Slug
	}
	payload := gin.H{
		"id":                  article.ID,
		"category_id":         article.CategoryID,
		"title":               article.Title,
		"content":             article.Content,
		"description":         article.Description,
		"status":              article.Status,
		"position":            article.Position,
		"account_id":          article.AccountID,
		"last_updated_at":     article.UpdatedAt,
		"slug":                article.Slug,
		"views":               article.Views,
		"associated_articles": publicAssociatedArticlePayloads(article.AssociatedArticles),
		"link":                "hc/" + portalSlug + "/articles/" + article.Slug,
	}
	if article.Portal.ID != 0 {
		payload["portal"] = publicPortalPayload(&article.Portal)
	}
	if article.Category != nil && article.Category.ID != 0 {
		payload["category"] = gin.H{"id": article.Category.ID, "slug": article.Category.Slug, "locale": article.Category.Locale}
	}
	if article.Author != nil && article.Author.ID != 0 {
		payload["author"] = publicAuthorPayload(article.Author)
	}
	return payload
}

func publicSearchArticlePayloads(articles []model.Article, portalSlug, query string) []gin.H {
	payload := make([]gin.H, 0, len(articles))
	for i := range articles {
		payload = append(payload, publicSearchArticlePayload(&articles[i], portalSlug, query))
	}
	return payload
}

func publicSearchArticlePayload(article *model.Article, portalSlug, query string) gin.H {
	if article == nil {
		return gin.H{}
	}
	return gin.H{
		"id":          article.ID,
		"category_id": article.CategoryID,
		"title":       article.Title,
		"content":     publicSearchArticleSnippet(article.Content, query),
		"link":        "/hc/" + portalSlug + "/articles/" + article.Slug,
	}
}

var publicSearchHTMLTagPattern = regexp.MustCompile(`<[^>]*>`)

func publicSearchArticleSnippet(content, query string) string {
	plain := publicSearchPlainText(content)
	if plain == "" {
		return ""
	}
	lowerPlain := strings.ToLower(plain)
	lowerQuery := strings.ToLower(strings.TrimSpace(query))
	if lowerQuery != "" {
		if idx := strings.Index(lowerPlain, lowerQuery); idx >= 0 {
			start := idx - 110
			if start < 0 {
				start = 0
			}
			end := idx + len(query) + 110
			if end > len(plain) {
				end = len(plain)
			}
			snippet := strings.TrimSpace(plain[start:end])
			if start > 0 {
				snippet = "..." + snippet
			}
			if end < len(plain) {
				snippet += "..."
			}
			return snippet
		}
	}
	return publicSearchTruncate(plain, 220)
}

func publicSearchPlainText(content string) string {
	text := publicSearchHTMLTagPattern.ReplaceAllString(content, " ")
	replacements := []string{"#", "*", "_", "`", ">", "[", "]", "(", ")", "!"}
	for _, old := range replacements {
		text = strings.ReplaceAll(text, old, " ")
	}
	return strings.Join(strings.Fields(text), " ")
}

func publicSearchTruncate(text string, limit int) string {
	if limit <= 0 || len(text) <= limit {
		return text
	}
	cut := text[:limit]
	if idx := strings.LastIndex(cut, " "); idx > 0 {
		cut = cut[:idx]
	}
	return strings.TrimSpace(cut) + "..."
}

func publicAssociatedArticlePayloads(articles []model.Article) []gin.H {
	payload := make([]gin.H, 0, len(articles))
	for i := range articles {
		article := &articles[i]
		item := gin.H{
			"id":              article.ID,
			"category_id":     article.CategoryID,
			"title":           article.Title,
			"content":         article.Content,
			"description":     article.Description,
			"status":          article.Status,
			"account_id":      article.AccountID,
			"last_updated_at": article.UpdatedAt,
			"views":           article.Views,
		}
		if article.Author != nil && article.Author.ID != 0 {
			item["author"] = publicAuthorPayload(article.Author)
		}
		payload = append(payload, item)
	}
	return payload
}

func publicPortalPayload(portal *model.Portal) gin.H {
	if portal == nil {
		return gin.H{}
	}
	categories := make([]gin.H, 0, len(portal.Categories))
	for i := range portal.Categories {
		categories = append(categories, publicCategoryPayload(&portal.Categories[i]))
	}
	payload := gin.H{
		"custom_domain": portal.CustomDomain,
		"header_text":   portal.HeaderText,
		"homepage_link": portal.HomepageLink,
		"name":          portal.Name,
		"page_title":    portal.PageTitle,
		"slug":          portal.Slug,
		"categories":    categories,
		"meta": gin.H{
			"articles_count":   publicPortalPublishedArticleCount(portal.Articles),
			"categories_count": len(portal.Categories),
			"default_locale":   portalDefaultLocale(portal),
		},
	}
	if portal.LogoURL != "" {
		payload["logo"] = gin.H{"file_url": portal.LogoURL, "portal_id": portal.ID, "account_id": portal.AccountID}
	}
	return payload
}

func publicPortalPublishedArticleCount(articles []model.Article) int {
	count := 0
	for _, article := range articles {
		if article.Status == string(model.ArticleStatusPublished) {
			count++
		}
	}
	return count
}

func publicAuthorPayload(user *model.User) gin.H {
	if user == nil {
		return gin.H{}
	}
	availableName := user.DisplayName
	if availableName == "" {
		availableName = user.Name
	}
	return gin.H{"available_name": availableName, "name": user.Name, "thumbnail": user.AvatarURL}
}

func articleListMetaPayload(meta *service.ArticleListMeta, currentPage int) gin.H {
	return gin.H{
		"all_articles_count":      meta.AllArticlesCount,
		"archived_articles_count": meta.ArchivedArticlesCount,
		"articles_count":          meta.ArticlesCount,
		"current_page":            currentPage,
		"draft_articles_count":    meta.DraftArticlesCount,
		"mine_articles_count":     meta.MineArticlesCount,
		"published_count":         meta.PublishedCount,
	}
}

func articleMetaPayload(raw json.RawMessage) map[string]any {
	if len(raw) == 0 {
		return map[string]any{}
	}
	var obj map[string]any
	if err := json.Unmarshal(raw, &obj); err != nil || obj == nil {
		return map[string]any{}
	}
	return obj
}

func renderArticleBulkError(c *gin.Context, err error) {
	message := "failed to update articles"
	switch {
	case errors.Is(err, service.ErrArticleBulkNoArticles):
		message = "No articles found"
	case errors.Is(err, service.ErrArticleBulkInvalidStatus):
		message = "Invalid status"
	case errors.Is(err, service.ErrArticleBulkCategoryNotFound):
		message = "Category not found"
	case errors.Is(err, service.ErrArticleBulkCaptainNotAvailable):
		message = "Captain is not available"
	case errors.Is(err, service.ErrArticleBulkLocaleNotAvailable):
		message = "Locale is not available"
	default:
		message = err.Error()
	}
	c.JSON(http.StatusUnprocessableEntity, gin.H{"error": message})
}