Update docs (very basic yet)

Author: led02

docs/source/dev/data_model.md

@@ -16,73 +16,28 @@ All the data is collected in a directory called `.hermes` located in the root of
 You should not need to interact with this data directly.
 Instead, use {class}`hermes.model.context.HermesContext` and respective subclasses to access the data in a consistent way.
 
-
-## Harvest Data
-
-The data of the havesters is cached in the sub-directory `.hermes/harvest`.
-
-
 ## Data representation
 
-We are trying to be fully JSON-LD compliant. However, there are two special cases, where we are a bit more lazy:
+*hermes* operates on expanded JSON-LD datasets.
+All internal data must be valid JSON-LD datasets in expanded form.
+All internal data must use CodeMeta vocabulary where applicable.
+All vocabulary used in internal datasets must be defined by a JSON-LD context.
 
-- Storing provenance of harvested data (for later curation)
-- Storing alternatives of harvested data (for later curation)
+*hermes* provides classes that facilitate the access to the expanded JSON-LD data.
 
-Internally, `hermes` works with the expanded version of the JSON-LD file.
-However, there are helper classes that allow you to use compact references.
+### *hermes* internal processing data
 
-For the storing of provenance and alternatives, we introduce our own terms.
-Especially, we add a `hermes:meta` key to the top level record.
-This top level key contains a list of additional meta-metadata (i.e., provenance and alternatives).
+*hermes* collects internal processing information in the `hermes-rt` namespace.
 
-Each entry in the meta-metadata list is a dictionary that contains at least a `reference` value and one or more of
-`provenance` and `alternative` keys.
-The `refrence` value should be a valid JSON Path that references the object that is subject to these metadata.
-The `provenance` value should be a JSON dataset that keeps information about where the data came from.
-The `alternative` value should be a list with alternative records.
+## Data cache
 
-Each alternative record contains a `value` and probably an additional `provenance` key.
+For each processing step there exists a command directory in the `.hermes` dir.
+Within this command, there exists one further plugin directory for each plugin.
+Within this plugin diretory, there are up to for files stores:
 
-Example:
+- `codemeta.json`: The (possibly extended) CodeMeta data representation of the dataset.
+  This should be valid compact JSON-LD data.
+- `expanded.json`: The expanded representation of the dataset. This should be valid expanded JSON-LD data.
+- `context.json`: The JSON-LD context that can be used to transform `expanded.json` into `codemeta.json`.
+- `prov.json`: A JSON-LD dataset that contains the provenance collected by *hermes* during the run.
 
-```json
-{
-	"@context": [
-		"https://doi.org/10.5063/schema/codemeta-2.0",
-		{"hermes": "https://schema.software-metadata.pub/hermes/1.0"},
-		{"legalName": {"@id": "schema:name"}}
-	],
-	"@type": "SoftwareSourceCode",
-	"author": [
-		{
-			"@id": "https://orcid.org/0000-0001-6372-3853",
-			"@type": "Person",
-			"affiliation": {
-				"@type": "Organization",
-				"legalName": "German Aerospace Center (DLR)"
-			},
-			"familyName": "Meinel",
-			"givenName": "Michael",
-			"email": "michael.meinel@dlr.de"
-		}
-	],
-	"description": "Tool to automate software publication. Not stable yet.",
-	"identifier": "https://doi.org/10.5281/zenodo.13221384",
-	"license": "https://spdx.org/licenses/Apache-2.0",
-	"name": "hermes",
-	"version": "0.8.1",
-	"hermes:meta": [
-		{
-			"reference": "$",
-			"provenance": { "harvester": "cff", "source": "CITATION.cff" }
-		},
-		{
-			"reference": "$.author.0.affiliation.legalName",
-			"alternative": [
-				{"value": "DLR e.V.", "provenance": { "harvester": "orcid" }}
-			],
-		}
-	]
-}
-```