package main

// The highest number held per kind (hq issue 488): what the issue tracker's reserve starts and raises its decision
// and research counters above (ADR 0275 rule 8, ADR 0290 rule 5), now that the records live here and hq's folders
// empty. Every number held counts — accepted, proposed, reserved or withdrawn — since each is spent.

import (
	"context"
	"errors"
	"fmt"

	stdio "git.novox.be/novox/mesh-sdk/go"
)

// HighestTool is the module's tool the issue tracker asks.
const HighestTool = "knowledge_highest"

// Highest is the highest number held of each kind, and how many records are held.
type Highest struct {
	Decision int    `json:"decision"`
	Research int    `json:"research"`
	Records  int    `json:"records"`
	Says     string `json:"says"`
}

// HighestHeld is the highest number held per kind. A knowledge base that holds no record answers none: a counter
// started from it would start at 1.
func (k *KB) HighestHeld() (*Highest, error) {
	all, err := k.Store.All(context.Background())
	if err != nil {
		return nil, fmt.Errorf("the knowledge base cannot be read (%v); it answers no highest number", err)
	}
	h := &Highest{Records: len(all)}
	for _, e := range all {
		switch r := e.Current; r.Kind {
		case KindDecision:
			h.Decision = max(h.Decision, r.Number)
		case KindResearch:
			h.Research = max(h.Research, r.Number)
		}
	}
	if h.Records == 0 {
		return nil, errors.New("the knowledge base holds no record yet (it is imported from hq once): it answers no highest number")
	}
	h.Says = fmt.Sprintf("The highest numbers held, of %d records, every number spent counted: decision %04d, research %03d.",
		h.Records, h.Decision, h.Research)
	return h, nil
}

func highestTool(k *KB) stdio.Tool {
	return stdio.Tool{Name: HighestTool,
		Description: "The highest decision number and the highest research number the knowledge base holds, every number spent " +
			"counted: accepted, proposed, reserved or withdrawn. The issue tracker starts and raises its counters above them. " +
			"Refused while the knowledge base holds no record, or cannot be read: a number is never guessed.",
		Input: schema(nil, map[string]any{}),
		Run: func(m map[string]any) (any, error) {
			if _, err := readArgs(HighestTool, m); err != nil {
				return nil, err
			}
			return k.HighestHeld()
		}}
}