package handlers

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

	"github.com/go-chi/chi/v5"

	"qctextbuilder/internal/buildsvc"
	"qctextbuilder/internal/draftsvc"
	"qctextbuilder/internal/onboarding"
	"qctextbuilder/internal/templatesvc"
)

type API struct {
	templateSvc *templatesvc.Service
	onboardSvc  *onboarding.Service
	draftSvc    *draftsvc.Service
	buildSvc    buildsvc.Service
}

func NewAPI(templateSvc *templatesvc.Service, onboardSvc *onboarding.Service, draftSvc *draftsvc.Service, buildSvc buildsvc.Service) *API {
	return &API{
		templateSvc: templateSvc,
		onboardSvc:  onboardSvc,
		draftSvc:    draftSvc,
		buildSvc:    buildSvc,
	}
}

func (a *API) Health(w http.ResponseWriter, _ *http.Request) {
	writeJSON(w, http.StatusOK, map[string]any{"status": "ok"})
}

func (a *API) SyncTemplates(w http.ResponseWriter, r *http.Request) {
	templates, err := a.templateSvc.SyncAITemplates(r.Context())
	if err != nil {
		writeJSON(w, http.StatusBadGateway, map[string]any{"error": err.Error()})
		return
	}
	writeJSON(w, http.StatusOK, map[string]any{"count": len(templates), "templates": templates})
}

func (a *API) ListTemplates(w http.ResponseWriter, r *http.Request) {
	templates, err := a.templateSvc.ListTemplates(r.Context())
	if err != nil {
		writeJSON(w, http.StatusBadRequest, map[string]any{"error": err.Error()})
		return
	}
	writeJSON(w, http.StatusOK, map[string]any{"count": len(templates), "templates": templates})
}

func (a *API) GetTemplateDetail(w http.ResponseWriter, r *http.Request) {
	rawID := chi.URLParam(r, "id")
	templateID, err := strconv.ParseInt(rawID, 10, 64)
	if err != nil {
		writeJSON(w, http.StatusBadRequest, map[string]any{"error": "invalid template id"})
		return
	}

	detail, err := a.templateSvc.GetTemplateDetail(r.Context(), templateID)
	if err != nil {
		writeJSON(w, http.StatusNotFound, map[string]any{"error": err.Error()})
		return
	}
	writeJSON(w, http.StatusOK, detail)
}

func (a *API) OnboardTemplate(w http.ResponseWriter, r *http.Request) {
	rawID := chi.URLParam(r, "id")
	templateID, err := strconv.ParseInt(rawID, 10, 64)
	if err != nil {
		writeJSON(w, http.StatusBadRequest, map[string]any{"error": "invalid template id"})
		return
	}

	manifest, fields, err := a.onboardSvc.OnboardTemplate(r.Context(), templateID)
	if err != nil {
		writeJSON(w, http.StatusBadRequest, map[string]any{"error": err.Error()})
		return
	}
	writeJSON(w, http.StatusOK, map[string]any{
		"manifestId": manifest.ID,
		"fieldCount": len(fields),
		"status":     "reviewed",
	})
}

type updateTemplateFieldsRequest struct {
	ManifestID string                    `json:"manifestId"`
	Fields     []updateTemplateFieldItem `json:"fields"`
}

type updateTemplateFieldItem struct {
	Path           string  `json:"path"`
	IsEnabled      *bool   `json:"isEnabled,omitempty"`
	IsRequiredByUs *bool   `json:"isRequiredByUs,omitempty"`
	DisplayLabel   *string `json:"displayLabel,omitempty"`
	DisplayOrder   *int    `json:"displayOrder,omitempty"`
	WebsiteSection *string `json:"websiteSection,omitempty"`
	Notes          *string `json:"notes,omitempty"`
}

func (a *API) UpdateTemplateFields(w http.ResponseWriter, r *http.Request) {
	rawID := chi.URLParam(r, "id")
	templateID, err := strconv.ParseInt(rawID, 10, 64)
	if err != nil {
		writeJSON(w, http.StatusBadRequest, map[string]any{"error": "invalid template id"})
		return
	}

	var req updateTemplateFieldsRequest
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		writeJSON(w, http.StatusBadRequest, map[string]any{"error": "invalid JSON body"})
		return
	}
	if len(req.Fields) == 0 {
		writeJSON(w, http.StatusBadRequest, map[string]any{"error": "fields is required"})
		return
	}

	patches := make([]onboarding.FieldPatch, 0, len(req.Fields))
	for _, f := range req.Fields {
		patches = append(patches, onboarding.FieldPatch{
			Path:           f.Path,
			IsEnabled:      f.IsEnabled,
			IsRequiredByUs: f.IsRequiredByUs,
			DisplayLabel:   f.DisplayLabel,
			DisplayOrder:   f.DisplayOrder,
			WebsiteSection: f.WebsiteSection,
			Notes:          f.Notes,
		})
	}

	manifest, fields, err := a.onboardSvc.UpdateTemplateFields(r.Context(), templateID, req.ManifestID, patches)
	if err != nil {
		writeJSON(w, http.StatusBadRequest, map[string]any{"error": err.Error()})
		return
	}

	writeJSON(w, http.StatusOK, map[string]any{
		"templateId": templateID,
		"manifestId": manifest.ID,
		"fieldCount": len(fields),
		"fields":     fields,
	})
}

func (a *API) StartBuild(w http.ResponseWriter, r *http.Request) {
	var req buildsvc.StartBuildRequest
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		writeJSON(w, http.StatusBadRequest, map[string]any{"error": "invalid JSON body"})
		return
	}

	result, err := a.buildSvc.StartBuild(r.Context(), req)
	if err != nil {
		writeJSON(w, http.StatusBadRequest, map[string]any{"error": err.Error()})
		return
	}
	writeJSON(w, http.StatusAccepted, result)
}

type upsertDraftRequest struct {
	TemplateID  int64             `json:"templateId"`
	ManifestID  string            `json:"manifestId"`
	Source      string            `json:"source"`
	RequestName string            `json:"requestName"`
	GlobalData  map[string]any    `json:"globalData"`
	FieldValues map[string]string `json:"fieldValues"`
	Status      string            `json:"status"`
	Notes       string            `json:"notes"`
}

func (a *API) IntakeDraft(w http.ResponseWriter, r *http.Request) {
	var req upsertDraftRequest
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		writeJSON(w, http.StatusBadRequest, map[string]any{"error": "invalid JSON body"})
		return
	}
	draft, err := a.draftSvc.SaveDraft(r.Context(), draftsvc.UpsertDraftRequest{
		TemplateID:  req.TemplateID,
		ManifestID:  req.ManifestID,
		Source:      defaultStr(req.Source, "intake-api"),
		RequestName: req.RequestName,
		GlobalData:  req.GlobalData,
		FieldValues: req.FieldValues,
		Status:      defaultStr(req.Status, "draft"),
		Notes:       req.Notes,
	})
	if err != nil {
		writeJSON(w, http.StatusBadRequest, map[string]any{"error": err.Error()})
		return
	}
	writeJSON(w, http.StatusCreated, draft)
}

func (a *API) ListDrafts(w http.ResponseWriter, r *http.Request) {
	limit, _ := strconv.Atoi(strings.TrimSpace(r.URL.Query().Get("limit")))
	drafts, err := a.draftSvc.ListDrafts(r.Context(), limit)
	if err != nil {
		writeJSON(w, http.StatusBadRequest, map[string]any{"error": err.Error()})
		return
	}
	writeJSON(w, http.StatusOK, map[string]any{"count": len(drafts), "drafts": drafts})
}

func (a *API) GetDraft(w http.ResponseWriter, r *http.Request) {
	draftID := strings.TrimSpace(chi.URLParam(r, "id"))
	draft, err := a.draftSvc.GetDraft(r.Context(), draftID)
	if err != nil {
		writeJSON(w, http.StatusNotFound, map[string]any{"error": err.Error()})
		return
	}
	writeJSON(w, http.StatusOK, draft)
}

func (a *API) UpdateDraft(w http.ResponseWriter, r *http.Request) {
	draftID := strings.TrimSpace(chi.URLParam(r, "id"))
	var req upsertDraftRequest
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		writeJSON(w, http.StatusBadRequest, map[string]any{"error": "invalid JSON body"})
		return
	}
	draft, err := a.draftSvc.SaveDraft(r.Context(), draftsvc.UpsertDraftRequest{
		DraftID:     draftID,
		TemplateID:  req.TemplateID,
		ManifestID:  req.ManifestID,
		Source:      req.Source,
		RequestName: req.RequestName,
		GlobalData:  req.GlobalData,
		FieldValues: req.FieldValues,
		Status:      req.Status,
		Notes:       req.Notes,
	})
	if err != nil {
		writeJSON(w, http.StatusBadRequest, map[string]any{"error": err.Error()})
		return
	}
	writeJSON(w, http.StatusOK, draft)
}

func (a *API) GetBuild(w http.ResponseWriter, r *http.Request) {
	buildID := chi.URLParam(r, "id")
	build, err := a.buildSvc.GetBuild(r.Context(), buildID)
	if err != nil {
		writeJSON(w, http.StatusNotFound, map[string]any{"error": err.Error()})
		return
	}
	writeJSON(w, http.StatusOK, build)
}

func (a *API) PollBuildOnce(w http.ResponseWriter, r *http.Request) {
	buildID := chi.URLParam(r, "id")
	if err := a.buildSvc.PollOnce(r.Context(), buildID); err != nil {
		writeJSON(w, http.StatusBadRequest, map[string]any{"error": err.Error()})
		return
	}

	build, err := a.buildSvc.GetBuild(r.Context(), buildID)
	if err != nil {
		writeJSON(w, http.StatusNotFound, map[string]any{"error": err.Error()})
		return
	}
	writeJSON(w, http.StatusOK, build)
}

func (a *API) FetchBuildEditorURL(w http.ResponseWriter, r *http.Request) {
	buildID := chi.URLParam(r, "id")
	if err := a.buildSvc.FetchEditorURL(r.Context(), buildID); err != nil {
		writeJSON(w, http.StatusBadRequest, map[string]any{"error": err.Error()})
		return
	}

	build, err := a.buildSvc.GetBuild(r.Context(), buildID)
	if err != nil {
		writeJSON(w, http.StatusNotFound, map[string]any{"error": err.Error()})
		return
	}
	writeJSON(w, http.StatusOK, build)
}

func writeJSON(w http.ResponseWriter, status int, v any) {
	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(status)
	_ = json.NewEncoder(w).Encode(v)
}

func defaultStr(v, fallback string) string {
	if strings.TrimSpace(v) == "" {
		return fallback
	}
	return strings.TrimSpace(v)
}