// skate-resolve-journal-name works on TSV where one column (-f, 1-indexed) is
// a release schema (json). It will inspect the container name and will resolve
// journal name abbreviations and will augment the release document with data
// in extra containing the resolved name (e.g. in
// extra.skate.resolved_container_name).
//
// The abbreviation file format currently is a JSONL format, each document
// containing a "name" (required) and "abbrev" (optional), e.g. like:
// https://git.archive.org/martin/cgraph/-/raw/master/extra/abbrev/jabbrev.json.
package main

import (
	"bufio"
	"bytes"
	"flag"
	"fmt"
	"io"
	"log"
	"os"
	"runtime"
	"strings"

	"git.archive.org/martin/cgraph/skate"
	"git.archive.org/martin/cgraph/skate/parallel"
	"git.archive.org/martin/cgraph/skate/set"
	json "github.com/segmentio/encoding/json"
)

var (
	numWorkers       = flag.Int("w", runtime.NumCPU(), "number of workers")
	batchSize        = flag.Int("b", 100000, "batch size")
	column           = flag.Int("f", 2, "column to find the release schema document in (1-indexed)")
	sep              = flag.String("d", "\t", "delimiter to use")
	bestEffort       = flag.Bool("B", false, "only log errors, do not halt")
	abbrevFile       = flag.String("A", "", "path to abbreviations file")
	keepResolvedOnly = flag.Bool("R", false, "keep only lines, where we could resolve an abbreviation")
)

func main() {
	flag.Parse()
	ms, m, err := createAbbreviationMatchSet(*abbrevFile)
	if err != nil {
		log.Fatal(err)
	}
	log.Printf("found %d abbreviation mappings", len(m))
	pp := parallel.NewProcessor(os.Stdin, os.Stdout, func(p []byte) ([]byte, error) {
		var (
			release *skate.Release
			err     error
		)
		fields := bytes.Split(p, []byte(*sep))
		if *column > len(fields) {
			return nil, fmt.Errorf("column mismatch")
		}
		if err = json.Unmarshal(fields[*column-1], &release); err != nil {
			if *bestEffort {
				log.Printf("failed to unmarshal: %v", string(p))
			} else {
				return nil, err
			}
		}
		// XXX: we do not need to do any lookup w/o container name anyway.
		if *keepResolvedOnly && release.ContainerName == "" {
			return nil, nil
		}
		name := strings.ToLower(release.ContainerName)
		results := ms.Lookup(name, -1)
		if len(results) != 1 {
			// To many or too few matches? We return the document unchanged
			if *keepResolvedOnly {
				return nil, nil
			} else {
				return p, nil
			}
		}
		resolved := m[results[0]]
		if len(resolved) != 1 {
			// Abbreviation mapping to different full names? Not sure how
			// common, or why, but skip.
			if *keepResolvedOnly {
				return nil, nil
			} else {
				return p, nil
			}
		}
		release.Extra.Skate.ResolvedContainerName = resolved[0]
		b, err := json.Marshal(release)
		if err != nil {
			return nil, err
		}
		if len(fields) == *column {
			// In case this is the last field, we want our newline back.
			b = append(b, []byte("\n")...)
		}
		fields[*column-1] = b
		return bytes.Join(fields, []byte(*sep)), nil
	})
	pp.NumWorkers = *numWorkers
	pp.BatchSize = *batchSize
	if err := pp.Run(); err != nil {
		log.Fatal(err)
	}
}

// createAbbreviationMatchSet creates a match set from JSONL abbreviations
// file. It also returns a mapping from abbreviations to full journal names for
// that abbreviation.
func createAbbreviationMatchSet(filename string) (*skate.MatchSet, map[string][]string, error) {
	f, err := os.Open(filename)
	if err != nil {
		return nil, nil, err
	}
	defer f.Close()
	var (
		sm         = make(map[string]set.Set)
		m          = make(map[string][]string)
		br         = bufio.NewReader(f)
		nameAbbrev struct {
			Name   string `json:"name"`
			Abbrev string `json:"abbrev"`
		}
		abbrevs []string
		key     string
	)
	for {
		b, err := br.ReadBytes('\n')
		if err == io.EOF {
			break
		}
		if err != nil {
			return nil, nil, err
		}
		if err := json.Unmarshal(b, &nameAbbrev); err != nil {
			return nil, nil, err
		}
		key = strings.ToLower(nameAbbrev.Abbrev)
		if _, ok := sm[key]; !ok {
			sm[key] = set.New()
		}
		sm[key].Add(strings.ToLower(nameAbbrev.Name))
	}
	for k, v := range sm {
		abbrevs = append(abbrevs, k)
		m[k] = v.Slice()
	}
	matchSet := skate.NewMatchSet(abbrevs)
	return matchSet, m, nil
}