package v1

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

	"github.com/gin-gonic/gin"
	"gorm.io/gorm"

	"github.com/gochat/gochat/internal/model"
	"github.com/gochat/gochat/internal/repository"
	"github.com/gochat/gochat/internal/search"
	"github.com/gochat/gochat/internal/service"
	"github.com/gochat/gochat/pkg/response"
)

// ContactHandler handles contact-related API endpoints.
// Reference: Chatwoot app/controllers/api/v1/contacts_controller.rb
type ContactHandler struct {
	svc             *service.ContactService
	contactInboxSvc *service.ContactInboxService
	mergeSvc        *service.ContactMergeService
	contactNoteSvc  *service.ContactNoteService
	conversationSvc *service.ConversationService
}

const chatwootContactResultsPerPage = 15

// NewContactHandler creates a new ContactHandler.
func NewContactHandler(svc *service.ContactService, contactInboxSvc *service.ContactInboxService, mergeSvc *service.ContactMergeService, contactNoteSvc *service.ContactNoteService, conversationSvc ...*service.ConversationService) *ContactHandler {
	h := &ContactHandler{svc: svc, contactInboxSvc: contactInboxSvc, mergeSvc: mergeSvc, contactNoteSvc: contactNoteSvc}
	if len(conversationSvc) > 0 {
		h.conversationSvc = conversationSvc[0]
	}
	return h
}

// @Summary List contacts for an account
// @Description Retrieves all contacts for an account with pagination and optional sort
// @Tags Contacts
// @Accept json
// @Produce json
// @Param id path uint true "Account ID"
// @Param sort query string false "Sort field" default(name)
// @Param page query int false "Page number" default(1)
// @Param page_size query int false "Items per page" default(25)
// @Success 200 {object} []model.Contact
// @Failure 400 {object} model.ErrorResponse
// @Failure 401 {object} model.ErrorResponse
// @Failure 500 {object} model.ErrorResponse
// @Security ApiKeyAuth
// @Router /api/v1/accounts/{id}/contacts [get]
// List retrieves all contacts for an account.
// GET /api/v1/accounts/:id/contacts?sort=name&page=1&page_size=25
// Reference: Chatwoot contacts#index (sort param)
func (h *ContactHandler) List(c *gin.Context) {
	accountID := parseAccountIDParam(c)
	if accountID == 0 {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid account id"})
		return
	}

	page := getPage(c)
	perPage := chatwootContactResultsPerPage
	offset := (page - 1) * perPage
	sort := c.DefaultQuery("sort", "")

	contacts, total, svcErr := h.svc.ListByAccount(c.Request.Context(), accountID, offset, perPage, sort, contactLabelsParam(c))
	if svcErr != nil {
		c.JSON(http.StatusUnprocessableEntity, gin.H{"error": "failed to list contacts"})
		return
	}

	c.JSON(http.StatusOK, contactListResponse(c.Request.Context(), h.svc.DB(), contacts, total, page, includeContactInboxes(c), nil))
}

// @Summary Search contacts
// @Description Searches contacts by query string with pagination, sort, and search mode support
// @Tags Contacts
// @Accept json
// @Produce json
// @Param id path uint true "Account ID"
// @Param q query string true "Search query"
// @Param sort query string false "Sort field"
// @Param search_mode query string false "Search mode (prefix/semantic/fulltext)" default(prefix)
// @Param page query int false "Page number" default(1)
// @Param page_size query int false "Items per page" default(25)
// @Success 200 {object} []model.Contact
// @Failure 400 {object} model.ErrorResponse
// @Failure 401 {object} model.ErrorResponse
// @Failure 500 {object} model.ErrorResponse
// @Security ApiKeyAuth
// @Router /api/v1/accounts/{id}/contacts/search [get]
// Search searches contacts by query with sort support.
// GET /api/v1/accounts/:id/contacts/search?q=...&sort=name
// Reference: Chatwoot contacts#search
func (h *ContactHandler) Search(c *gin.Context) {
	accountID := parseAccountIDParam(c)
	if accountID == 0 {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid account id"})
		return
	}

	query := c.Query("q")
	if query == "" {
		c.JSON(http.StatusUnprocessableEntity, gin.H{"error": "Specify search string with parameter q"})
		return
	}
	page := getPage(c)
	perPage := chatwootContactResultsPerPage
	offset := (page - 1) * perPage
	sort := c.DefaultQuery("sort", "")
	searchMode := search.ParseSearchMode(c.DefaultQuery("search_mode", ""))

	contacts, total, svcErr := h.svc.Search(c.Request.Context(), accountID, query, offset, perPage, sort, searchMode, contactLabelsParam(c))
	if svcErr != nil {
		c.JSON(http.StatusUnprocessableEntity, gin.H{"error": "failed to search contacts"})
		return
	}

	hasMore := int64(len(contacts)) < total
	c.JSON(http.StatusOK, contactListResponse(c.Request.Context(), h.svc.DB(), contacts, int64(len(contacts)), page, includeContactInboxes(c), &hasMore))
}

// @Summary Get a single contact
// @Description Retrieves detailed information about a specific contact within an account
// @Tags Contacts
// @Accept json
// @Produce json
// @Param id path uint true "Account ID"
// @Param contact_id path uint true "Contact ID"
// @Success 200 {object} model.Contact
// @Failure 400 {object} model.ErrorResponse
// @Failure 401 {object} model.ErrorResponse
// @Failure 404 {object} model.ErrorResponse
// @Failure 500 {object} model.ErrorResponse
// @Security ApiKeyAuth
// @Router /api/v1/accounts/{id}/contacts/{contact_id} [get]
// Get retrieves a single contact.
// GET /api/v1/accounts/:id/contacts/:contact_id
func (h *ContactHandler) Get(c *gin.Context) {
	accountID := parseAccountIDParam(c)
	if accountID == 0 {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid account id"})
		return
	}

	contactID, err := parseUintParam(c, "contact_id")
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid contact id"})
		return
	}

	contact, svcErr := h.svc.GetByAccountAndID(c.Request.Context(), accountID, contactID)
	if svcErr != nil {
		c.JSON(http.StatusNotFound, gin.H{"error": "contact not found"})
		return
	}

	c.JSON(http.StatusOK, contactPayloadResponse(c.Request.Context(), h.svc.DB(), contact, includeContactInboxes(c)))
}

// @Summary Create a new contact
// @Description Creates a new contact, optionally auto-creating a ContactInbox when inbox_id is provided
// @Tags Contacts
// @Accept json
// @Produce json
// @Param id path uint true "Account ID"
// @Param body body service.CreateContactRequest true "Contact creation payload"
// @Success 201 {object} model.Contact
// @Failure 400 {object} model.ErrorResponse
// @Failure 401 {object} model.ErrorResponse
// @Failure 500 {object} model.ErrorResponse
// @Security ApiKeyAuth
// @Router /api/v1/accounts/{id}/contacts [post]
// Create creates a new contact, optionally auto-creating a ContactInbox.
// POST /api/v1/accounts/:id/contacts
// Body: {name, email, phone, inbox_id, source_id, ...}
// Reference: Chatwoot contacts#create (auto-creates ContactInbox when inbox_id provided)
func (h *ContactHandler) Create(c *gin.Context) {
	accountID := parseAccountIDParam(c)
	if accountID == 0 {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid account id"})
		return
	}

	var req service.CreateContactRequest
	if bindErr := c.ShouldBindJSON(&req); bindErr != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": bindErr.Error()})
		return
	}

	contact, svcErr := h.svc.Create(c.Request.Context(), accountID, req)
	if svcErr != nil {
		c.JSON(http.StatusUnprocessableEntity, gin.H{"error": "failed to create contact"})
		return
	}

	var contactInbox *model.ContactInbox
	if h.svc.DB() != nil {
		var ci model.ContactInbox
		if err := h.svc.DB().WithContext(c.Request.Context()).Preload("Inbox").Where("contact_id = ?", contact.ID).Order("id DESC").First(&ci).Error; err == nil {
			contactInbox = &ci
		}
	}
	c.JSON(http.StatusOK, contactCreateResponse(c.Request.Context(), h.svc.DB(), contact, contactInbox))
}

// @Summary Update a contact
// @Description Modifies an existing contact's details
// @Tags Contacts
// @Accept json
// @Produce json
// @Param id path uint true "Account ID"
// @Param contact_id path uint true "Contact ID"
// @Param body body service.UpdateContactRequest true "Contact update payload"
// @Success 200 {object} model.Contact
// @Failure 400 {object} model.ErrorResponse
// @Failure 401 {object} model.ErrorResponse
// @Failure 404 {object} model.ErrorResponse
// @Failure 500 {object} model.ErrorResponse
// @Security ApiKeyAuth
// @Router /api/v1/accounts/{id}/contacts/{contact_id} [put]
// Update modifies an existing contact.
// PUT /api/v1/accounts/:id/contacts/:contact_id
func (h *ContactHandler) Update(c *gin.Context) {
	accountID := parseAccountIDParam(c)
	if accountID == 0 {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid account id"})
		return
	}

	contactID, err := parseUintParam(c, "contact_id")
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid contact id"})
		return
	}

	var req service.UpdateContactRequest
	if bindErr := c.ShouldBindJSON(&req); bindErr != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": bindErr.Error()})
		return
	}

	contact, svcErr := h.svc.Update(c.Request.Context(), accountID, contactID, req)
	if svcErr != nil {
		c.JSON(http.StatusUnprocessableEntity, gin.H{"error": "failed to update contact"})
		return
	}

	c.JSON(http.StatusOK, contactPayloadResponse(c.Request.Context(), h.svc.DB(), contact, includeContactInboxes(c)))
}

// @Summary Delete a contact
// @Description Soft-deletes a contact from an account
// @Tags Contacts
// @Accept json
// @Produce json
// @Param id path uint true "Account ID"
// @Param contact_id path uint true "Contact ID"
// @Success 200 {object} object
// @Failure 400 {object} model.ErrorResponse
// @Failure 401 {object} model.ErrorResponse
// @Failure 404 {object} model.ErrorResponse
// @Failure 500 {object} model.ErrorResponse
// @Security ApiKeyAuth
// @Router /api/v1/accounts/{id}/contacts/{contact_id} [delete]
// Delete soft-deletes a contact.
// DELETE /api/v1/accounts/:id/contacts/:contact_id
func (h *ContactHandler) Delete(c *gin.Context) {
	accountID := parseAccountIDParam(c)
	if accountID == 0 {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid account id"})
		return
	}

	contactID, err := parseUintParam(c, "contact_id")
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid contact id"})
		return
	}

	if svcErr := h.svc.Delete(c.Request.Context(), accountID, contactID); svcErr != nil {
		c.JSON(http.StatusUnprocessableEntity, gin.H{"error": "failed to delete contact"})
		return
	}

	c.Status(http.StatusOK)
}

func (h *ContactHandler) InitiateCall(c *gin.Context) {
	accountID := parseAccountIDParam(c)
	if accountID == 0 {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid account id"})
		return
	}
	contactID, err := parseUintParam(c, "contact_id")
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid contact id"})
		return
	}
	userID := getUserID(c)
	if userID == 0 {
		c.JSON(http.StatusUnauthorized, gin.H{"error": "user not authenticated"})
		return
	}

	var body struct {
		InboxID        uint  `json:"inbox_id" binding:"required"`
		ConversationID *uint `json:"conversation_id"`
	}
	if bindErr := c.ShouldBindJSON(&body); bindErr != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": bindErr.Error()})
		return
	}

	result, svcErr := h.svc.InitiateCall(c.Request.Context(), accountID, contactID, service.InitiateContactCallRequest{
		InboxID:        body.InboxID,
		ConversationID: body.ConversationID,
		UserID:         userID,
	})
	if svcErr != nil {
		if errors.Is(svcErr, gorm.ErrRecordNotFound) {
			c.JSON(http.StatusNotFound, gin.H{"error": "resource not found"})
			return
		}
		c.JSON(http.StatusUnprocessableEntity, gin.H{"error": svcErr.Error()})
		return
	}
	c.JSON(http.StatusOK, result)
}

func (h *ContactHandler) DeleteAvatar(c *gin.Context) {
	accountID := parseAccountIDParam(c)
	if accountID == 0 {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid account id")
		return
	}
	contactID, err := parseUintParam(c, "contact_id")
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid contact id")
		return
	}
	contact, svcErr := h.svc.DeleteAvatar(c.Request.Context(), accountID, contactID)
	if svcErr != nil {
		handleServiceError(c, svcErr)
		return
	}
	c.JSON(http.StatusOK, contactPayloadResponse(c.Request.Context(), h.svc.DB(), contact, false))
}

func (h *ContactHandler) ListLabels(c *gin.Context) {
	accountID := parseAccountIDParam(c)
	if accountID == 0 {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid account id")
		return
	}
	contactID, err := parseUintParam(c, "contact_id")
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid contact id")
		return
	}
	labels, svcErr := h.svc.GetLabels(c.Request.Context(), accountID, contactID)
	if svcErr != nil {
		handleServiceError(c, svcErr)
		return
	}
	c.JSON(http.StatusOK, gin.H{"payload": labels})
}

func (h *ContactHandler) UpdateLabels(c *gin.Context) {
	accountID := parseAccountIDParam(c)
	if accountID == 0 {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid account id")
		return
	}
	contactID, err := parseUintParam(c, "contact_id")
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid contact id")
		return
	}
	var req struct {
		Labels []string `json:"labels"`
	}
	if err := c.ShouldBindJSON(&req); err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrValidation, err.Error())
		return
	}
	labels, svcErr := h.svc.UpdateLabels(c.Request.Context(), accountID, contactID, req.Labels)
	if svcErr != nil {
		handleServiceError(c, svcErr)
		return
	}
	c.JSON(http.StatusOK, gin.H{"payload": labels})
}

// ListContactInboxes retrieves all contact_inboxes for a contact.
// GET /api/v1/accounts/:id/contacts/:contact_id/contact_inboxes
// Reference: Chatwoot contacts#contact_inboxes (nested resource)
func (h *ContactHandler) ListContactInboxes(c *gin.Context) {
	contactID, err := parseUintParam(c, "contact_id")
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid contact id"})
		return
	}

	contactInboxes, svcErr := h.svc.ListContactInboxes(c.Request.Context(), contactID)
	if svcErr != nil {
		c.JSON(http.StatusUnprocessableEntity, gin.H{"error": "failed to list contact inboxes"})
		return
	}

	payload := make([]any, 0, len(contactInboxes))
	for i := range contactInboxes {
		payload = append(payload, serializeContactInbox(&contactInboxes[i]))
	}
	c.JSON(http.StatusOK, gin.H{"payload": payload, "meta": gin.H{"count": len(payload)}})
}

// ListConversations retrieves recent conversations for a contact.
// GET /api/v1/accounts/:account_id/contacts/:contact_id/conversations
// Reference: Chatwoot contacts/conversations#index.
func (h *ContactHandler) ListConversations(c *gin.Context) {
	accountID := parseAccountIDParam(c)
	if accountID == 0 {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid account id"})
		return
	}

	contactID, err := parseUintParam(c, "contact_id")
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid contact id"})
		return
	}

	if !h.svc.Ready() || h.conversationSvc == nil {
		c.JSON(http.StatusUnprocessableEntity, gin.H{"error": "failed to list contact conversations"})
		return
	}
	if _, svcErr := h.svc.GetByAccountAndID(c.Request.Context(), accountID, contactID); svcErr != nil {
		handleServiceError(c, svcErr)
		return
	}

	var inboxID *uint
	if rawInboxID := c.Query("inbox_id"); rawInboxID != "" {
		parsed, parseErr := strconv.ParseUint(rawInboxID, 10, 32)
		if parseErr != nil {
			c.JSON(http.StatusBadRequest, gin.H{"error": "invalid inbox id"})
			return
		}
		id := uint(parsed)
		inboxID = &id
	}

	conversations, svcErr := h.conversationSvc.ListRecentByContact(c.Request.Context(), accountID, contactID, inboxID, 20)
	if svcErr != nil {
		c.JSON(http.StatusUnprocessableEntity, gin.H{"error": "failed to list contact conversations"})
		return
	}

	c.JSON(http.StatusOK, gin.H{"payload": serializeConversationPayloads(c.Request.Context(), h.svc.DB(), conversations)})
}

// ListNotes retrieves notes for a contact.
// GET /api/v1/accounts/:id/contacts/:contact_id/notes
// Reference: Chatwoot contacts#notes
func (h *ContactHandler) ListNotes(c *gin.Context) {
	accountID := parseAccountIDParam(c)
	if accountID == 0 {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid account id"})
		return
	}

	contactID, err := parseUintParam(c, "contact_id")
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid contact id"})
		return
	}

	notes, svcErr := h.svc.ListNotes(c.Request.Context(), accountID, contactID)
	if svcErr != nil {
		c.JSON(http.StatusUnprocessableEntity, gin.H{"error": "failed to list notes"})
		return
	}

	c.JSON(http.StatusOK, contactNotesResponse(notes))
}

// CreateNote creates a note for a contact.
// POST /api/v1/accounts/:id/contacts/:contact_id/notes
// Reference: Chatwoot contacts#create_note
func (h *ContactHandler) CreateNote(c *gin.Context) {
	accountID := parseAccountIDParam(c)
	if accountID == 0 {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid account id"})
		return
	}

	contactID, err := parseUintParam(c, "contact_id")
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid contact id"})
		return
	}

	userID := getUserID(c)
	if userID == 0 {
		c.JSON(http.StatusUnauthorized, gin.H{"error": "user not authenticated"})
		return
	}

	req, bindErr := bindContactNoteRequest(c)
	if bindErr != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": bindErr.Error()})
		return
	}

	note, svcErr := h.svc.CreateNote(c.Request.Context(), accountID, contactID, userID, req)
	if svcErr != nil {
		c.JSON(http.StatusUnprocessableEntity, gin.H{"error": "failed to create note"})
		return
	}

	c.JSON(http.StatusOK, serializeContactNote(note))
}

// ShowNote retrieves a single note for a contact.
// GET /api/v1/accounts/:account_id/contacts/:contact_id/notes/:id
func (h *ContactHandler) ShowNote(c *gin.Context) {
	accountID := parseAccountIDParam(c)
	if accountID == 0 {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid account id")
		return
	}

	noteID, err := parseUintParam(c, "note_id")
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid note id")
		return
	}

	contactID, err := parseUintParam(c, "contact_id")
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid contact id")
		return
	}

	note, svcErr := h.svc.GetNote(c.Request.Context(), accountID, contactID, noteID)
	if svcErr != nil {
		handleServiceError(c, svcErr)
		return
	}

	c.JSON(http.StatusOK, serializeContactNote(note))
}

// UpdateNote updates a note on a contact.
// PATCH /api/v1/accounts/:account_id/contacts/:contact_id/notes/:id
func (h *ContactHandler) UpdateNote(c *gin.Context) {
	accountID := parseAccountIDParam(c)
	if accountID == 0 {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid account id")
		return
	}

	noteID, err := parseUintParam(c, "note_id")
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid note id")
		return
	}

	contactID, err := parseUintParam(c, "contact_id")
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid contact id")
		return
	}

	req, bindErr := bindContactNoteRequest(c)
	if bindErr != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrValidation, bindErr.Error())
		return
	}

	note, svcErr := h.svc.UpdateNote(c.Request.Context(), accountID, contactID, noteID, req)
	if svcErr != nil {
		handleServiceError(c, svcErr)
		return
	}

	c.JSON(http.StatusOK, serializeContactNote(note))
}

// DestroyNote deletes a note on a contact.
// DELETE /api/v1/accounts/:account_id/contacts/:contact_id/notes/:id
func (h *ContactHandler) DestroyNote(c *gin.Context) {
	accountID := parseAccountIDParam(c)
	if accountID == 0 {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid account id")
		return
	}

	noteID, err := parseUintParam(c, "note_id")
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid note id")
		return
	}

	contactID, err := parseUintParam(c, "contact_id")
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid contact id")
		return
	}

	if svcErr := h.svc.DeleteNote(c.Request.Context(), accountID, contactID, noteID); svcErr != nil {
		handleServiceError(c, svcErr)
		return
	}

	c.Status(http.StatusOK)
}

func bindContactNoteRequest(c *gin.Context) (service.CreateNoteRequest, error) {
	var body struct {
		Content string `json:"content"`
		Note    struct {
			Content string `json:"content"`
		} `json:"note"`
	}
	if err := c.ShouldBindJSON(&body); err != nil {
		return service.CreateNoteRequest{}, err
	}
	content := body.Content
	if content == "" {
		content = body.Note.Content
	}
	return service.CreateNoteRequest{Content: content}, nil
}

func includeContactInboxes(c *gin.Context) bool {
	if raw := c.Query("include_contact_inboxes"); raw != "" {
		return raw == "true"
	}
	return true
}

func contactLabelsParam(c *gin.Context) []string {
	labels := c.QueryArray("labels[]")
	labels = append(labels, c.QueryArray("labels")...)
	return labels
}

// parseIntOrDefault parses an integer query parameter with a default value.
func parseIntOrDefault(c *gin.Context, key string, defaultVal int) int {
	val := c.Query(key)
	if val == "" {
		return defaultVal
	}
	n, err := strconv.Atoi(val)
	if err != nil {
		return defaultVal
	}
	return n
}

// CreateContactInbox adds a contact-inbox association (linking a contact to an inbox).
// POST /api/v1/accounts/:id/contacts/:contact_id/contact_inboxes
// Reference: Chatwoot contact_inboxes#create
func (h *ContactHandler) CreateContactInbox(c *gin.Context) {
	accountID := parseAccountIDParam(c)
	if accountID == 0 {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid account id"})
		return
	}

	contactID, err := parseUintParam(c, "contact_id")
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid contact id"})
		return
	}

	contact, svcErr := h.svc.GetByAccountAndID(c.Request.Context(), accountID, contactID)
	if svcErr != nil {
		c.JSON(http.StatusNotFound, gin.H{"error": "contact not found"})
		return
	}

	req, bindErr := parseNestedContactInboxCreateParams(c)
	if bindErr != nil || req.InboxID == 0 {
		c.JSON(http.StatusBadRequest, gin.H{"error": "inbox_id is required"})
		return
	}

	var inbox model.Inbox
	db := h.svc.DB()
	if db == nil || db.WithContext(c.Request.Context()).Where("account_id = ? AND id = ?", accountID, req.InboxID).First(&inbox).Error != nil {
		c.JSON(http.StatusNotFound, gin.H{"error": "inbox not found"})
		return
	}

	ci, svcErr := h.contactInboxSvc.Create(c.Request.Context(), service.CreateContactInboxRequest{
		ContactID:    contact.ID,
		InboxID:      inbox.ID,
		SourceID:     req.SourceID,
		HMACVerified: req.HMACVerified,
		Contact:      contact,
		Inbox:        &inbox,
	})
	if svcErr != nil {
		c.JSON(http.StatusUnprocessableEntity, gin.H{"error": "failed to create contact inbox"})
		return
	}

	c.JSON(http.StatusOK, serializeContactInbox(ci))
}

type nestedContactInboxCreateParams struct {
	InboxID      uint
	SourceID     string
	HMACVerified bool
}

func parseNestedContactInboxCreateParams(c *gin.Context) (nestedContactInboxCreateParams, error) {
	params := nestedContactInboxCreateParams{}
	if strings.Contains(strings.ToLower(c.GetHeader("Content-Type")), "application/json") {
		var body map[string]any
		if err := c.ShouldBindJSON(&body); err != nil && !errors.Is(err, io.EOF) {
			return params, err
		}
		params.InboxID = uintValue(body["inbox_id"])
		params.SourceID = stringValue(body["source_id"])
		params.HMACVerified = boolValue(body["hmac_verified"])
	} else {
		if err := c.Request.ParseForm(); err != nil {
			return params, err
		}
		params.InboxID = uintStringValue(c.PostForm("inbox_id"))
		params.SourceID = c.PostForm("source_id")
		params.HMACVerified = boolStringValue(c.PostForm("hmac_verified"))
	}
	if value := c.Query("inbox_id"); value != "" {
		params.InboxID = uintStringValue(value)
	}
	if value := c.Query("source_id"); value != "" {
		params.SourceID = value
	}
	if value := c.Query("hmac_verified"); value != "" {
		params.HMACVerified = boolStringValue(value)
	}
	return params, nil
}

func uintValue(value any) uint {
	switch v := value.(type) {
	case float64:
		return uint(v)
	case json.Number:
		if n, err := strconv.ParseUint(string(v), 10, 64); err == nil {
			return uint(n)
		}
	case string:
		return uintStringValue(v)
	}
	return 0
}

func uintStringValue(value string) uint {
	n, err := strconv.ParseUint(strings.TrimSpace(value), 10, 64)
	if err != nil {
		return 0
	}
	return uint(n)
}

func stringValue(value any) string {
	if v, ok := value.(string); ok {
		return v
	}
	return ""
}

func boolValue(value any) bool {
	switch v := value.(type) {
	case bool:
		return v
	case string:
		return boolStringValue(v)
	}
	return false
}

func boolStringValue(value string) bool {
	parsed, err := strconv.ParseBool(strings.TrimSpace(value))
	return err == nil && parsed
}

// DeleteContactInbox removes a contact-inbox association.
// DELETE /api/v1/accounts/:id/contacts/:contact_id/contact_inboxes/:inbox_id
// Reference: Chatwoot contact_inboxes#destroy
func (h *ContactHandler) DeleteContactInbox(c *gin.Context) {
	contactID, err := parseUintParam(c, "contact_id")
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid contact id"})
		return
	}

	inboxID, err := parseUintParam(c, "inbox_id")
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid inbox id"})
		return
	}

	if svcErr := h.contactInboxSvc.DeleteByContactAndInbox(c.Request.Context(), contactID, inboxID); svcErr != nil {
		c.JSON(http.StatusUnprocessableEntity, gin.H{"error": "failed to delete contact inbox"})
		return
	}

	c.JSON(http.StatusOK, gin.H{"contact_id": contactID, "inbox_id": inboxID, "deleted": true})
}

// Active retrieves contacts with recent activity.
// GET /api/v1/accounts/:id/contacts/active?sort=name&page=1
// Reference: Chatwoot contacts#active
func (h *ContactHandler) Active(c *gin.Context) {
	accountID := parseAccountIDParam(c)
	if accountID == 0 {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid account id"})
		return
	}

	page := getPage(c)
	perPage := chatwootContactResultsPerPage
	offset := (page - 1) * perPage
	sort := c.DefaultQuery("sort", "")
	if !h.svc.Ready() {
		c.JSON(http.StatusUnprocessableEntity, gin.H{"error": "failed to list active contacts"})
		return
	}

	contacts, total, svcErr := h.svc.ListActive(c.Request.Context(), accountID, offset, perPage, sort)
	if svcErr != nil {
		c.JSON(http.StatusUnprocessableEntity, gin.H{"error": "failed to list active contacts"})
		return
	}

	c.JSON(http.StatusOK, contactListResponse(c.Request.Context(), h.svc.DB(), contacts, total, page, includeContactInboxes(c), nil))
}

// Export downloads contacts as CSV.
// GET /api/v1/accounts/:id/contacts/export
// Reference: Chatwoot contacts#export
func (h *ContactHandler) Export(c *gin.Context) {
	accountID := parseAccountIDParam(c)
	if accountID == 0 {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid account id"})
		return
	}

	c.Header("Content-Type", "text/csv")
	c.Header("Content-Disposition", "attachment; filename=contacts.csv")

	if svcErr := h.svc.ExportCSV(c.Request.Context(), accountID, c.Writer); svcErr != nil {
		c.JSON(http.StatusUnprocessableEntity, gin.H{"error": "failed to export contacts"})
		return
	}
}

// ExportRequest accepts Chatwoot's asynchronous contact export request.
// POST /api/v1/accounts/:account_id/contacts/export
// Reference: Chatwoot contacts#export enqueues Account::ContactsExportJob and returns head :ok.
func (h *ContactHandler) ExportRequest(c *gin.Context) {
	accountID := parseAccountIDParam(c)
	if accountID == 0 {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid account id"})
		return
	}
	if !h.svc.Ready() {
		c.JSON(http.StatusUnprocessableEntity, gin.H{"error": "failed to export contacts"})
		return
	}

	var req service.ContactExportRequest
	if err := c.ShouldBindJSON(&req); err != nil && err != io.EOF {
		c.JSON(http.StatusUnprocessableEntity, gin.H{"error": "failed to export contacts"})
		return
	}

	if _, svcErr := h.svc.ExportContacts(c.Request.Context(), accountID, getUserID(c), req); svcErr != nil {
		c.JSON(http.StatusUnprocessableEntity, gin.H{"error": "failed to export contacts"})
		return
	}

	c.Status(http.StatusOK)
}

// DownloadExport streams a previously generated contacts export artifact.
func (h *ContactHandler) DownloadExport(c *gin.Context) {
	accountID := parseAccountIDParam(c)
	if accountID == 0 {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid account id"})
		return
	}
	exportID, err := parseUintParam(c, "export_id")
	if err != nil || exportID == 0 {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid export id"})
		return
	}
	export, svcErr := h.svc.GetContactExport(c.Request.Context(), accountID, exportID)
	if svcErr != nil || len(export.CSVData) == 0 {
		c.JSON(http.StatusNotFound, gin.H{"error": "export not found"})
		return
	}
	c.Header("Content-Disposition", "attachment; filename="+export.FileName)
	c.Data(http.StatusOK, export.ContentType, export.CSVData)
}

// Import uploads contacts from a CSV file.
// POST /api/v1/accounts/:id/contacts/import
// Reference: Chatwoot contacts#import
func (h *ContactHandler) Import(c *gin.Context) {
	accountID := parseAccountIDParam(c)
	if accountID == 0 {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid account id"})
		return
	}

	file, _, fileErr := c.Request.FormFile("import_file")
	if fileErr != nil {
		file, _, fileErr = c.Request.FormFile("file")
	}
	if fileErr != nil {
		c.JSON(http.StatusUnprocessableEntity, gin.H{"error": "failed to import contacts"})
		return
	}
	defer file.Close()

	_, svcErr := h.svc.ImportContacts(c.Request.Context(), accountID, getUserID(c), file)
	if svcErr != nil {
		c.JSON(http.StatusUnprocessableEntity, gin.H{"error": "failed to import contacts"})
		return
	}

	c.Status(http.StatusOK)
}

// ContactableInboxes returns inboxes that a contact can be associated with.
// GET /api/v1/accounts/:id/contacts/:contact_id/contactable_inboxes
// Reference: Chatwoot contacts#contactable_inboxes
func (h *ContactHandler) ContactableInboxes(c *gin.Context) {
	accountID := parseAccountIDParam(c)
	if accountID == 0 {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid account id"})
		return
	}

	contactID, err := parseUintParam(c, "contact_id")
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid contact id"})
		return
	}

	inboxes, svcErr := h.svc.GetContactableInboxes(c.Request.Context(), accountID, contactID)
	if svcErr != nil {
		c.JSON(http.StatusUnprocessableEntity, gin.H{"error": "failed to get contactable inboxes"})
		return
	}

	payload := make([]any, 0, len(inboxes))
	for _, item := range inboxes {
		payload = append(payload, map[string]any{"inbox": serializeInboxSlim(&item.Inbox), "source_id": item.SourceID})
	}
	c.JSON(http.StatusOK, gin.H{"payload": payload})
}

// ListAttachments returns a contact's shared files across all visible conversations.
// GET /api/v1/accounts/:id/contacts/:contact_id/attachments
// Reference: Chatwoot Api::V1::Accounts::Contacts::AttachmentsController#index
func (h *ContactHandler) ListAttachments(c *gin.Context) {
	accountID := parseAccountIDParam(c)
	if accountID == 0 {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid account id"})
		return
	}

	contactID, err := parseUintParam(c, "contact_id")
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid contact id"})
		return
	}

	_, offset := fixedPageOffset(c, chatwootAttachmentResultsPerPage)
	attachments, total, svcErr := h.svc.ListAttachments(c.Request.Context(), accountID, contactID, offset, chatwootAttachmentResultsPerPage)
	if svcErr != nil {
		c.JSON(http.StatusUnprocessableEntity, gin.H{"error": "failed to list contact attachments"})
		return
	}

	payload := make([]any, 0, len(attachments))
	for i := range attachments {
		payload = append(payload, serializeAttachmentWithConversation(c.Request.Context(), h.svc.DB(), &attachments[i]))
	}
	c.JSON(http.StatusOK, gin.H{"meta": gin.H{"total_count": total}, "payload": payload})
}

// DeleteCustomAttributes removes all custom attributes from a contact.
// DELETE /api/v1/accounts/:id/contacts/:contact_id/custom_attributes
// Reference: Chatwoot contacts#destroy_custom_attributes
func (h *ContactHandler) DeleteCustomAttributes(c *gin.Context) {
	accountID := parseAccountIDParam(c)
	if accountID == 0 {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid account id"})
		return
	}

	contactID, err := parseUintParam(c, "contact_id")
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid contact id"})
		return
	}

	if svcErr := h.svc.DeleteCustomAttributes(c.Request.Context(), accountID, contactID); svcErr != nil {
		c.JSON(http.StatusUnprocessableEntity, gin.H{"error": "failed to delete custom attributes"})
		return
	}

	contact, svcErr := h.svc.GetByAccountAndID(c.Request.Context(), accountID, contactID)
	if svcErr != nil {
		c.JSON(http.StatusUnprocessableEntity, gin.H{"error": "failed to load contact"})
		return
	}
	c.JSON(http.StatusOK, contactPayloadResponse(c.Request.Context(), h.svc.DB(), contact, true))
}

// Merge two contacts into one. The base contact survives, mergee is deleted.
// POST /api/v1/accounts/:id/contacts/merge
// Reference: Chatwoot app/controllers/api/v1/accounts/actions/contact_merges_controller.rb
func (h *ContactHandler) Merge(c *gin.Context) {
	accountID := parseAccountIDParam(c)
	if accountID == 0 {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid account id"})
		return
	}

	var req service.MergeRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid request: base_contact_id and mergee_contact_id required"})
		return
	}

	result, svcErr := h.mergeSvc.MergeWithRequest(c.Request.Context(), accountID, req)
	if svcErr != nil {
		handleServiceError(c, svcErr)
		return
	}

	c.JSON(http.StatusOK, serializeCRMContact(c.Request.Context(), h.svc.DB(), result, false))
}

// Filter retrieves contacts matching advanced filter criteria.
// POST /api/v1/accounts/:id/contacts/filter
// Reference: Chatwoot contacts#filter — uses ContactFilterService with payload params.
func (h *ContactHandler) Filter(c *gin.Context) {
	accountID := parseAccountIDParam(c)
	if accountID == 0 {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid account id"})
		return
	}

	var params repository.ContactFilterParams
	if err := c.ShouldBindJSON(&params); err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, err.Error())
		return
	}

	page := getPage(c)
	perPage := chatwootContactResultsPerPage
	offset := (page - 1) * perPage
	contacts, total, svcErr := h.svc.Filter(c.Request.Context(), accountID, params, offset, perPage)
	if svcErr != nil {
		c.JSON(http.StatusUnprocessableEntity, gin.H{"error": "failed to filter contacts"})
		return
	}

	c.JSON(http.StatusOK, contactListResponse(c.Request.Context(), h.svc.DB(), contacts, total, page, includeContactInboxes(c), nil))
}

// DestroyCustomAttributes removes all custom attributes from a contact.
// POST /api/v1/accounts/:id/contacts/:contact_id/destroy_custom_attributes
// Reference: Chatwoot contacts#destroy_custom_attributes — uses POST method.
// This is an alias for DeleteCustomAttributes (which uses DELETE method) to match Chatwoot's API.
func (h *ContactHandler) DestroyCustomAttributes(c *gin.Context) {
	accountID := parseAccountIDParam(c)
	if accountID == 0 {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid account id"})
		return
	}

	contactID, err := parseUintParam(c, "contact_id")
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid contact id"})
		return
	}

	var req struct {
		CustomAttributes []string `json:"custom_attributes"`
	}
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}
	contact, svcErr := h.svc.DestroyCustomAttributes(c.Request.Context(), accountID, contactID, req.CustomAttributes)
	if svcErr != nil {
		c.JSON(http.StatusUnprocessableEntity, gin.H{"error": "failed to destroy custom attributes"})
		return
	}

	c.JSON(http.StatusOK, contactPayloadResponse(c.Request.Context(), h.svc.DB(), contact, true))
}