// Copyright 2022 wanderer <a_mirre at utb dot cz>
// SPDX-License-Identifier: GPL-3.0-or-later

package report

import (
	"log"
	"os"
	"sort"
	"text/template"
	"time"

	"git.dotya.ml/wanderer/math-optim/util"
)

// Pic holds path to pic along with its caption.
type Pic struct {
	Caption  string
	FilePath string
}

// PicList is a structure holding a slice of pics and {bench,algo} metadata.
type PicList struct {
	Algo  string
	Bench string
	Pics  []Pic
}

// NewPic returns a new copy of Pic.
func NewPic() *Pic {
	return &Pic{}
}

// NewPicList returns a new copy of PicList.
func NewPicList() *PicList {
	return &PicList{}
}

// SavePicsToFile saves each pic list for all bench funcs of a specified algo
// to a file.
func SavePicsToFile(pls []PicList, algoName string) {
	var paths []string

	ptf := picTexFiles{Algo: algoName}

	for _, p := range pls {
		safeName := util.SanitiseFName(p.Algo + "-" + p.Bench)
		texPicsFile := GetTexDir() + "pics-" + safeName + ".tex"
		tmplPicsFile := "report/pics.tmpl"

		if _, err := os.Stat(tmplPicsFile); err != nil {
			// TODO(me): fix this, same as in table.go.
			// this block is relevant for the unit test path, somehow the file is
			// not found as defined above.
			log.Println(err, `, weird test behaviour , prepending "../"`)

			tmplPicsFile = "../" + tmplPicsFile
		}

		tmplPics := template.Must(template.ParseFiles(tmplPicsFile))

		paths = append(paths, texPicsFile)
		// keep the slice sorted.
		sort.Strings(paths)

		// make sure the output dir exists, else die early.
		if err := util.CreatePath(GetTexDir()); err != nil {
			log.Fatalln(err)
		}

		f, err := os.Create(texPicsFile)
		if err != nil {
			log.Println(err)
		}
		defer f.Close()

		err = tmplPics.Execute(f, struct {
			Algo      string
			Bench     string
			Pics      []Pic
			Timestamp time.Time
		}{
			Algo:      p.Algo,
			Bench:     p.Bench,
			Pics:      p.Pics,
			Timestamp: time.Now(),
		})

		if err != nil {
			log.Println(err)
		}
	}

	ptf.FilePaths = paths
	allPics.TexFiles = append(allPics.TexFiles, ptf)
}