package mapping

import (
	"strings"

	sdk "code.gitea.io/sdk/gitea"

	"git.noodles.cam/claude-skills/marketplace/cli/internal/issue"
)

// How the taxonomy is painted in Gitea's UI. A hex code says nothing about what
// an issue IS, which is exactly why the table lives here and not in the domain
// — internal/issue/taxonomy.go says as much where the labels themselves are.
//
// The keys are the canonical set and nothing else. TestEveryCanonicalLabelHasA
// Color walks issue.CanonicalLabels() and fails on a gap, so a type or a
// severity added over there cannot quietly arrive here as grey.
var labelColors = map[string]string{
	"type/bug":             "#ee0701",
	"type/task":            "#0e8a16",
	"type/refactor":        "#1d76db",
	"type/test":            "#fbca04",
	"type/feature":         "#5319e7",
	"type/draft":           "#cccccc",
	"severity/low":         "#c2e0c6",
	"severity/medium":      "#fbca04",
	"severity/high":        "#eb6420",
	"severity/showstopper": "#ee0701",
	"severity/critical":    "#b60205",
}

// DefaultColor paints everything outside the canonical set. `tech/*` and
// `comp/*` are project-specific and have no preset, so guessing a color for one
// would be inventing a meaning it does not have.
const DefaultColor = "#ededed"

// LabelColor is the hex code a label is painted with in the tracker.
func LabelColor(name string) string {
	if c, ok := labelColors[name]; ok {
		return c
	}
	return DefaultColor
}

// LabelSpecs is the request body for each name, in the order given.
//
// The SDK's own CreateLabelOption and not a shape of this package's own: it is
// field for field what a label create takes, and a second spelling of it would
// mean the bootstrap command copying four fields across on its way to the
// transport. It is what an EDIT is built from too — see Client.EditLabel — so
// one value says what a label should be, whether or not it exists yet.
// Exclusivity and meaning come from the domain taxonomy; only the color is
// decided here.
//
// A slice and not a map: the order is the taxonomy's, and a bootstrap prints
// its plan in that order — a map would shuffle the plan on every run and make
// two identical runs look like different ones.
func LabelSpecs(names []string) []sdk.CreateLabelOption {
	ns := exclusiveNamespaces()
	out := make([]sdk.CreateLabelOption, 0, len(names))
	for _, name := range names {
		out = append(out, sdk.CreateLabelOption{
			Name:        name,
			Color:       LabelColor(name),
			Description: typeMeaning(name),
			Exclusive:   hasAnyPrefix(name, ns),
		})
	}
	return out
}

// CanonicalLabelSpecs is the set a repository needs before a push can attach
// anything.
//
// Derived from the domain's own list rather than restated: add a type over in
// the taxonomy and the next bootstrap creates it, with no line changing here
// except the color it is painted with.
func CanonicalLabelSpecs() []sdk.CreateLabelOption { return LabelSpecs(issue.CanonicalLabels()) }

// exclusiveNamespaces are the namespaces at most one label may come from, read
// off the canonical set rather than listed again — the domain publishes exactly
// the exclusive namespaces there, in full, and that is what makes the set
// canonical.
//
// A prefix test and not a membership test, on purpose: a project's own
// `type/spike` is still exclusive. Being one of a set of alternatives is a
// property of the namespace, not of the members the taxonomy happens to know.
func exclusiveNamespaces() []string {
	var out []string
	seen := map[string]bool{}
	for _, name := range issue.CanonicalLabels() {
		ns, _, ok := strings.Cut(name, "/")
		if !ok || seen[ns] {
			continue
		}
		seen[ns] = true
		out = append(out, ns+"/")
	}
	return out
}

// typeMeaning is the description a `type/*` label carries into the tracker, so
// the meaning a reader needs is on the chip rather than in this repository.
// Nothing else gets one: a severity explains itself, and a project's own
// namespaces are not ours to describe.
func typeMeaning(name string) string {
	tail, ok := strings.CutPrefix(name, "type/")
	if !ok {
		return ""
	}
	for _, t := range issue.Types {
		if t.Name == tail {
			return t.Meaning
		}
	}
	return ""
}

func hasAnyPrefix(s string, prefixes []string) bool {
	for _, p := range prefixes {
		if strings.HasPrefix(s, p) {
			return true
		}
	}
	return false
}