package com.example.aiapp

/**
 * What a session with no model of its own is called, in the button and in the list it opens.
 *
 * One constant rather than a literal in each place, because the two have to agree: a picker whose
 * options cannot say every state its button can display is one you can leave and not get back to.
 * It is also the Claude CLI's own word for "whatever is configured".
 */
const val DEFAULT_MODEL = "default"

/**
 * A model's name as a person reads it.
 *
 * Providers answer with their own full identifier -- Claude Code resolves `haiku` to `claude-
 * haiku-4-5-20251001` and reports that, which is the honest answer to "what is this session using"
 * and far too long for a button in a row that also holds Stop and Send.
 *
 * So the two ends that identify nothing are dropped and nothing else is: the vendor prefix, which
 * is the same on every model this app can show, and the release date, which distinguishes builds of
 * one model rather than one model from another. Anything that does not look like that is returned
 * untouched.
 *
 * A llama.cpp session's model is not an identifier at all -- it is `owner/repo/file.gguf`, where
 * the file was downloaded from -- so what is kept is the file, which is the part that tells two
 * models apart, and the extension goes with the directories. The model's *own* name is better still
 * and is not derivable here: it is inside the file, and only the server has ever opened it. Where a
 * screen has the server's answer it should prefer it; this is the floor under every screen that
 * does not.
 *
 * A display decision, not a correction: the full name is what the session reports.
 */
fun modelLabel(model: String?): String {
    val name = model?.takeIf { it.isNotBlank() } ?: return DEFAULT_MODEL
    if (name.endsWith(GGUF)) {
        return name.substringAfterLast('/').removeSuffix(GGUF)
    }
    return name.removePrefix("claude-").replace(DATED_SUFFIX, "")
}

/** A trailing `-YYYYMMDD`, which is how these identifiers carry their release date. */
private val DATED_SUFFIX = Regex("""-\d{8}$""")

/** What every model a llama.cpp session can run is stored as. */
private const val GGUF = ".gguf"