package httpapi

import (
	"fmt"
	"net/http"
	"strconv"
	"strings"
	"time"

	"github.com/descrybe/descrybe-v2/apps/api/internal/feeds"
	"github.com/descrybe/descrybe-v2/apps/api/internal/marketing"
	"github.com/go-chi/chi/v5"
	"github.com/google/uuid"
)

// presentV1ExportFeed shapes an export feed for the legacy public API
// (presentExportFeed + v2 public_token extras).
func presentV1ExportFeed(item map[string]any) map[string]any {
	if item == nil {
		return map[string]any{}
	}
	out := map[string]any{
		"id":                item["id"],
		"name":              item["name"],
		"format":            item["format"],
		"root_xpath":        nil,
		"item_xpath":        nil,
		"mappings":          map[string]any{},
		"structure":         nil,
		"last_generated_at": item["last_generated_at"],
		"created_at":        item["created_at"],
		"updated_at":        item["updated_at"],
		"public_token":      item["public_token"],
		"is_active":         item["is_active"],
		"source_feed_id":    item["source_feed_id"],
	}
	if v, ok := item["template"]; ok && v != nil {
		out["structure"] = v
	}
	if v, ok := item["filters"]; ok && v != nil {
		out["filters"] = v
	}
	if token, _ := item["public_token"].(string); token != "" {
		format := strings.ToLower(strings.TrimSpace(fmt.Sprint(item["format"])))
		ext := "xml"
		if format == "csv" {
			ext = "csv"
		}
		path := "/api/public/export-feeds/" + token + "." + ext
		// Only advertise the matching extension — wrong-format URLs 404 and must not
		// be suggested (also avoids encouraging token-existence probes).
		out["public_urls"] = map[string]string{
			ext:     path,
			"token": path,
		}
	}
	return out
}

func (s *Server) handleV1ListExportFeeds(w http.ResponseWriter, r *http.Request) {
	cid, _ := CompanyIDFromContext(r.Context())
	page, limit, offset := ParsePageLimit(r)
	items, total, err := s.Feeds.ListExportFeeds(r.Context(), cid, limit, offset)
	if err != nil {
		Error(w, http.StatusInternalServerError, "list failed")
		return
	}
	out := make([]map[string]any, 0, len(items))
	for _, item := range items {
		out = append(out, presentV1ExportFeed(item))
	}
	v1OK(w, http.StatusOK, out, map[string]any{
		"page":  page,
		"limit": limit,
		"total": total,
	})
}

func (s *Server) handleV1CreateExportFeed(w http.ResponseWriter, r *http.Request) {
	cid, _ := CompanyIDFromContext(r.Context())
	var body struct {
		Name                string  `json:"name"`
		Format              string  `json:"format"`
		SourceFeedID        *string `json:"source_feed_id"`
		Template            any     `json:"template"`
		Structure           any     `json:"structure"`
		Mappings            any     `json:"mappings"`
		Filters             any     `json:"filters"`
		RootXpath           *string `json:"root_xpath"`
		ItemXpath           *string `json:"item_xpath"`
		OutputPath          *string `json:"output_path"`
		AttributeExportMode any     `json:"attribute_export_mode"`
	}
	if err := DecodeJSON(r, &body); err != nil {
		v1Err(w, http.StatusBadRequest, "validation_error", "invalid json")
		return
	}
	if strings.TrimSpace(body.Name) == "" || strings.TrimSpace(body.Format) == "" {
		v1Err(w, http.StatusBadRequest, "validation_error", "Missing required fields: name, format")
		return
	}
	tpl := body.Template
	if tpl == nil {
		tpl = body.Structure
	}
	if tpl == nil && body.Mappings != nil {
		tpl = map[string]any{"mappings": body.Mappings}
	}
	if tpl == nil && (body.RootXpath != nil || body.ItemXpath != nil) {
		m := map[string]any{}
		if body.RootXpath != nil {
			m["root"] = *body.RootXpath
		}
		if body.ItemXpath != nil {
			m["item"] = *body.ItemXpath
		}
		tpl = m
	}
	item, err := s.Feeds.CreateExportFeed(r.Context(), cid, feeds.CreateExportInput{
		Name: body.Name, SourceFeedID: body.SourceFeedID, Format: body.Format,
		Template: tpl, Filters: body.Filters,
	})
	if err != nil {
		if msg, ok := feeds.ClientError(err); ok {
			v1Err(w, http.StatusBadRequest, "validation_error", msg)
			return
		}
		ClientOrLog(w, http.StatusBadRequest, "could not create export feed", err, feeds.ClientError)
		return
	}
	v1OK(w, http.StatusCreated, presentV1ExportFeed(item), nil)
}

func (s *Server) handleV1GenerateExportFeed(w http.ResponseWriter, r *http.Request) {
	cid, _ := CompanyIDFromContext(r.Context())
	id, err := uuid.Parse(chi.URLParam(r, "id"))
	if err != nil {
		v1Err(w, http.StatusBadRequest, "validation_error", "invalid id")
		return
	}
	feed, err := s.Feeds.GetExportFeed(r.Context(), cid, id)
	if err != nil {
		v1Err(w, http.StatusNotFound, "not_found", "Export feed not found")
		return
	}
	result, err := s.Feeds.GenerateExportFeed(r.Context(), cid, id)
	if err != nil {
		if msg, ok := feeds.ClientError(err); ok {
			v1Err(w, http.StatusBadRequest, "generation_failed", msg)
			return
		}
		v1Err(w, http.StatusInternalServerError, "generation_failed", "Failed to generate export feed")
		return
	}
	format := strings.ToLower(strings.TrimSpace(fmt.Sprint(feed["format"])))
	if format == "" {
		format = strings.ToLower(strings.TrimSpace(fmt.Sprint(result["format"])))
	}
	ext := "xml"
	if format == "csv" {
		ext = "csv"
	}
	token, _ := feed["public_token"].(string)
	downloadURL := fmt.Sprintf("/api/export-feeds/%s/%s", id.String(), ext)
	if token != "" {
		downloadURL = fmt.Sprintf("/api/public/export-feeds/%s.%s", token, ext)
	}
	v1OK(w, http.StatusOK, map[string]any{
		"generated":         true,
		"format":            format,
		"filePath":          nil,
		"downloadUrl":       downloadURL,
		"products_exported": result["products_exported"],
		"last_generated_at": result["last_generated_at"],
		"status":            result["status"],
	}, nil)
}

// handleV1ListCampaigns is the legacy alias for GET /marketing/calendar
// (seasonal export prep — not email /api/campaigns).
func (s *Server) handleV1ListCampaigns(w http.ResponseWriter, r *http.Request) {
	payload, status, errCode, errMsg := s.v1MarketingCalendar(r)
	if errMsg != "" {
		v1Err(w, status, errCode, errMsg)
		return
	}
	v1OK(w, http.StatusOK, payload, nil)
}

// handleV1PrepareCampaign is the legacy alias for POST /marketing/calendar/prepare.
func (s *Server) handleV1PrepareCampaign(w http.ResponseWriter, r *http.Request) {
	cid, _ := CompanyIDFromContext(r.Context())
	var body struct {
		PresetID string `json:"preset_id"`
		Year     int    `json:"year"`
		Format   string `json:"format"`
		ForceNew bool   `json:"force_new"`
	}
	if err := DecodeJSON(r, &body); err != nil {
		v1Err(w, http.StatusBadRequest, "validation_error", "invalid json")
		return
	}
	campaign, err := s.marketingService().PrepareCampaign(r.Context(), cid, marketing.PrepareInput{
		PresetID: marketing.PresetID(body.PresetID),
		Year:     body.Year,
		Format:   body.Format,
		ForceNew: body.ForceNew,
	})
	if err != nil {
		if msg, ok := marketing.ClientError(err); ok {
			v1Err(w, http.StatusBadRequest, "validation_error", msg)
			return
		}
		ClientOrLog(w, http.StatusBadRequest, "could not prepare campaign", err, marketing.ClientError)
		return
	}
	status := http.StatusOK
	if campaign.Created {
		status = http.StatusCreated
	}
	v1OK(w, status, map[string]any{
		"preset_id":        campaign.PresetID,
		"name":             campaign.Name,
		"start_date":       campaign.StartDate,
		"end_date":         campaign.EndDate,
		"year":             campaign.Year,
		"export_feed_id":   campaign.ExportFeedID,
		"export_feed_name": campaign.ExportFeedName,
		"created":          campaign.Created,
	}, nil)
}

func (s *Server) v1MarketingCalendar(r *http.Request) (payload map[string]any, status int, errCode, errMsg string) {
	cid, _ := CompanyIDFromContext(r.Context())
	year := time.Now().UTC().Year()
	if y := r.URL.Query().Get("year"); y != "" {
		parsed, err := strconv.Atoi(y)
		if err != nil || parsed < 2000 || parsed > 2100 {
			return nil, http.StatusBadRequest, "validation_error", "Invalid year"
		}
		year = parsed
	}
	prepared, err := s.marketingService().ListPreparedCampaigns(r.Context(), cid)
	if err != nil {
		return nil, http.StatusInternalServerError, "list_failed", "list failed"
	}
	preparedOut := make([]map[string]any, 0, len(prepared))
	for _, c := range prepared {
		preparedOut = append(preparedOut, map[string]any{
			"preset_id":        c.PresetID,
			"name":             c.Name,
			"start_date":       c.StartDate,
			"end_date":         c.EndDate,
			"year":             c.Year,
			"export_feed_id":   c.ExportFeedID,
			"export_feed_name": c.ExportFeedName,
		})
	}
	return map[string]any{
		"year":     year,
		"presets":  marketing.ListPresets(year),
		"prepared": preparedOut,
	}, http.StatusOK, "", ""
}