package v3

import (
	"encoding/json"
	"htwkalender/service/functions"
	"log/slog"
	"net/http"
)

/*

{
  "@context": "/api/contexts/Modul",
  "@id": "/api/module",
  "@type": "hydra:Collection",
  "hydra:totalItems": 1678,
  "hydra:member": [
    {
      "@id": "/api/module/0055CE2545A3411A00C32F30A645463B",
      "@type": "Modul",
      "id": "0055CE2545A3411A00C32F30A645463B",
      "semester": "/api/semester/ws",
      "fakultaet": "/api/fakultaeten/9B89016985E5156B1C033BB0FD3AF9B4",
      "kuerzel": "PPKMSBM&SMM&STM3",
      "bezeichnung": "W833 Produkt- und Prozesskostenmanagement  SBM & SMM & STM 3. FS (wpf)",
      "hinweisOne": "",
      "internalUpdatedAt": "2023-03-07T07:35:34+01:00"
    }
  ],
  "hydra:view": {
    "@id": "/api/module?itemsPerPage=100&page=1",
    "@type": "hydra:PartialCollectionView",
    "hydra:first": "/api/module?itemsPerPage=100&page=1",
    "hydra:last": "/api/module?itemsPerPage=100&page=17",
    "hydra:next": "/api/module?itemsPerPage=100&page=2"
  },
  "hydra:search": {
    "@type": "hydra:IriTemplate",
    "hydra:template": "/api/module{?veranstaltungen,veranstaltungen[]}",
    "hydra:variableRepresentation": "BasicRepresentation",
    "hydra:mapping": [
      {
        "@type": "IriTemplateMapping",
        "variable": "veranstaltungen",
        "property": "veranstaltungen",
        "required": false
      },
      {
        "@type": "IriTemplateMapping",
        "variable": "veranstaltungen[]",
        "property": "veranstaltungen",
        "required": false
      }
    ]
  }
}


*/

// Module Model for fetching json data

type Modules struct {
	TotalItems int      `json:"hydra:totalItems"`
	Modules    []Module `json:"hydra:member"`
}

type Module struct {
	ID       string `json:"id"`
	Semester string `json:"semester"`
	Faculty  string `json:"fakultaet"`
	ShortCut string `json:"kuerzel"`
	Name     string `json:"bezeichnung"`
	Note     string `json:"hinweisOne"`
	Internal string `json:"internalUpdatedAt"`
}

func parseModules(url string, client *http.Client) (Modules, error) {

	// the url is paginated, so we need to fetch all pages
	// example url: https://luna.htwk-leipzig.de/api/module?page=1&itemsPerPage=100
	// the itemsPerPage is set to 100, so we need to fetch all pages until we get an empty response

	var fetchedModules Modules
	var itemsPerPage = 999

	responses, err := paginatedFetch(url, itemsPerPage, client)

	if err != nil {
		slog.Error("Error while fetching modules", err)
		return Modules{}, err
	}

	for _, response := range responses {
		var modules Modules
		err = json.Unmarshal([]byte(response), &modules)
		if err != nil {
			slog.Error("Error while unmarshalling modules", err)
			return Modules{}, err
		}

		// cut api iri prefix
		for i, module := range modules.Modules {

			modules.Modules[i].Faculty = functions.RemoveIriPrefix(module.Faculty, 32)
			modules.Modules[i].Semester = functions.RemoveIriPrefix(module.Semester, 2)
		}

		fetchedModules.Modules = append(fetchedModules.Modules, modules.Modules...)
		fetchedModules.TotalItems = modules.TotalItems
	}

	return fetchedModules, nil
}