// stuck.go overlays cad-atlas#11's stuck-state badges onto the pipeline: a
// count badge per stage (Node entries + Stage.StuckCount/AwaitingCount),
// sourced from mathias/cad#14's `cad stuck` query rather than re-implemented
// here. cad's app/domain packages are public Go modules (not internal/) —
// this reuses the exact tested classification logic instead of duplicating
// the taxonomy, per ADR-0002 ("a small coupling surface, not a monolith").
package atlas

import (
	"fmt"

	caddomain "git.d-ma.be/mathias/cad/domain"
)

// stageForCategory maps a cad-stuck taxonomy row onto the existing 9-stage
// pipeline (atlas.json), following the grouping cad-atlas#11 itself proposes:
// Trigger→armed-but-never-fired sits at the human dispatch gate (the label
// that authorizes dispatch is on, nothing has claimed it yet); Claim/Execute
// collapse into the one Execute stage this pipeline already has (there is no
// separate Claim stage); Close maps to the loop-back stage, where a human
// closing the issue is the action that actually completes the loop.
//
// CategoryDoneNotClosed is deliberately absent from the "stuck" class — see
// ApplyStuckOverlay, which reads Class rather than Category to decide the
// visual treatment. It IS present here for stage placement.
var stageForCategory = map[caddomain.StuckCategory]string{
	caddomain.CategoryArmedNeverFired: "STAGE 04",
	caddomain.CategoryClaimedNeverRan: "STAGE 05",
	caddomain.CategoryCeilingHit:      "STAGE 05",
	caddomain.CategoryReFireLoop:      "STAGE 05",
	caddomain.CategoryNearAttemptCap:  "STAGE 05",
	caddomain.CategoryDoneNotClosed:   "STAGE 08",
}

// stuckNodeCls / awaitingNodeCls are the CSS classes the static shell colours
// (cad-atlas.html: .node.stuck, .node.awaiting-human) — the two visual
// classes cad-atlas#11 asks for, kept visually distinct so "awaiting human"
// (a functioning control) never reads as "stuck" (needs intervention).
const (
	stuckNodeCls    = "stuck"
	awaitingNodeCls = "awaiting-human"
)

// ApplyStuckOverlay assigns each finding to the stage stageForCategory names,
// and for every stage in stages marked `"generate":"stuck-badges"`, sets its
// StuckCount/AwaitingCount and prepends one Node per finding assigned there
// (title, class, repo tag, and a URL to the finding's first locator — this
// overlay never adds a control, only a link out to Gitea). Findings whose
// category has no stage mapping are silently omitted from the pipeline view
// rather than misplaced — cad-atlas#11 is a read of the query, not a second
// copy of its taxonomy, so an unmapped category is a gap to notice in
// stageForCategory, not something to guess a stage for.
//
// stages is returned unmodified aside from the stuck-badges stages; this is a
// pure function, no I/O, so it is fixture-testable without a live query.
func ApplyStuckOverlay(stages []Stage, findings []caddomain.StuckFinding) []Stage {
	byStage := make(map[string][]caddomain.StuckFinding)
	for _, f := range findings {
		stageNo, ok := stageForCategory[f.Category]
		if !ok {
			continue
		}
		byStage[stageNo] = append(byStage[stageNo], f)
	}

	out := make([]Stage, len(stages))
	copy(out, stages)
	for i := range out {
		if out[i].Generate != "stuck-badges" {
			continue
		}
		assigned := byStage[out[i].No]
		var stuckN, awaitingN int
		nodes := make([]Node, 0, len(assigned))
		for _, f := range assigned {
			cls := stuckNodeCls
			if f.Class == caddomain.ClassAwaitingHuman {
				cls = awaitingNodeCls
				awaitingN++
			} else {
				stuckN++
			}
			var url string
			if len(f.Locators) > 0 {
				url = f.Locators[0]
			}
			nodes = append(nodes, Node{
				Title: fmt.Sprintf("#%d %s", f.Issue, f.Category),
				Desc:  f.Detail,
				Cls:   cls,
				Tags:  []string{"live · cad-stuck", f.Repo},
				URL:   url,
			})
		}
		out[i].StuckCount = stuckN
		out[i].AwaitingCount = awaitingN
		out[i].Nodes = append(nodes, out[i].Nodes...)
	}
	return out
}