package codegen

import (
	"fmt"
	"path/filepath"

	"github.com/grafana/codejen"
	"github.com/grafana/kindsys"
)

// LatestMajorsOrXJenny returns a jenny that repeats the input for the latest in each major version.
//
// TODO remove forceGroup option, it's a temporary hack to accommodate core kinds
func LatestMajorsOrXJenny(parentdir string, forceGroup bool, inner codejen.OneToOne[SchemaForGen]) OneToMany {
	if inner == nil {
		panic("inner jenny must not be nil")
	}

	return &lmox{
		parentdir:  parentdir,
		inner:      inner,
		forceGroup: forceGroup,
	}
}

type lmox struct {
	parentdir  string
	inner      codejen.OneToOne[SchemaForGen]
	forceGroup bool
}

func (j *lmox) JennyName() string {
	return "LatestMajorsOrXJenny"
}

func (j *lmox) Generate(kind kindsys.Kind) (codejen.Files, error) {
	// TODO remove this once codejen catches nils https://github.com/grafana/codejen/issues/5
	if kind == nil {
		return nil, nil
	}

	comm := kind.Props().Common()
	sfg := SchemaForGen{
		Name:    comm.Name,
		IsGroup: comm.LineageIsGroup,
	}

	if j.forceGroup {
		sfg.IsGroup = true
	}

	do := func(sfg SchemaForGen, infix string) (codejen.Files, error) {
		f, err := j.inner.Generate(sfg)
		if err != nil {
			return nil, fmt.Errorf("%s jenny failed on %s schema for %s: %w", j.inner.JennyName(), sfg.Schema.Version(), kind.Props().Common().Name, err)
		}
		if f == nil || !f.Exists() {
			return nil, nil
		}

		f.RelativePath = filepath.Join(j.parentdir, comm.MachineName, infix, f.RelativePath)
		f.From = append(f.From, j)
		return codejen.Files{*f}, nil
	}

	if comm.Maturity.Less(kindsys.MaturityStable) {
		sfg.Schema = kind.Lineage().Latest()
		return do(sfg, "x")
	}

	var fl codejen.Files
	major := -1
	for sch := kind.Lineage().First(); sch != nil; sch = sch.Successor() {
		if int(sch.Version()[0]) == major {
			continue
		}
		major = int(sch.Version()[0])

		sfg.Schema = sch.LatestInMajor()
		files, err := do(sfg, fmt.Sprintf("v%v", sch.Version()[0]))
		if err != nil {
			return nil, err
		}
		fl = append(fl, files...)
	}
	if fl.Validate() != nil {
		return nil, fl.Validate()
	}
	return fl, nil
}