package cobra

import (
	"fmt"
	"strings"

	commandmeta "gitea.maximumdirect.net/eric/CommandKit/internal/commandmeta"
)

func interpretFlagTokens(argv []string, flags []commandmeta.Flag, aliases []commandmeta.FlagAlias) ([]string, map[string][]string, []commandmeta.FlagOccurrence, *commandmeta.Failure) {
	canonical := make(map[string]commandmeta.Flag, len(flags)*2+2)
	help := commandmeta.Flag{Name: "help", Short: "h", Boolean: true}
	canonical["--help"] = help
	canonical["-h"] = help
	for _, flag := range flags {
		canonical["--"+flag.Name] = flag
		if flag.Short != "" {
			canonical["-"+flag.Short] = flag
		}
	}

	byAlias := make(map[string]commandmeta.Flag, len(aliases))
	for _, alias := range aliases {
		if target, ok := canonical[alias.Target]; ok {
			byAlias[alias.Source] = target
		}
	}

	spellings := make(map[string][]string)
	var occurrences []commandmeta.FlagOccurrence
	var interpreted []string
	for index := 0; index < len(argv); {
		token := argv[index]
		if token == "--" {
			interpreted = append(interpreted, argv[index:]...)
			break
		}
		if strings.HasPrefix(token, "--") && len(token) > 2 {
			body := token[2:]
			equal := strings.IndexByte(body, '=')
			inputName := body
			if equal >= 0 {
				inputName = body[:equal]
			}
			original := "--" + inputName
			flag, ok := canonical[original]
			if !ok {
				flag, ok = byAlias[original]
			}
			if !ok {
				interpreted = append(interpreted, token)
				return interpreted, spellings, occurrences, nil
			}
			spellings[flag.Name] = append(spellings[flag.Name], original)
			if equal >= 0 {
				value := body[equal+1:]
				interpreted = append(interpreted, "--"+flag.Name+"="+value)
				occurrences = append(occurrences, commandmeta.FlagOccurrence{Name: flag.Name, Spelling: original, RawValue: value})
				index++
				continue
			}
			if !flag.Boolean && index+1 < len(argv) {
				value := argv[index+1]
				interpreted = append(interpreted, "--"+flag.Name+"="+value)
				occurrences = append(occurrences, commandmeta.FlagOccurrence{Name: flag.Name, Spelling: original, RawValue: value})
				index += 2
				continue
			}
			if !flag.Boolean {
				return interpreted, spellings, occurrences, &commandmeta.Failure{Message: fmt.Sprintf("flag needs an argument: %s", original)}
			}
			occurrences = append(occurrences, commandmeta.FlagOccurrence{Name: flag.Name, Spelling: original, RawValue: "true"})
			interpreted = append(interpreted, "--"+flag.Name)
			index++
			continue
		}
		if len(token) > 1 && token[0] == '-' {
			if token == "-" {
				interpreted = append(interpreted, token)
				index++
				continue
			}
			consumedNext := false
			for offset := 1; offset < len(token); {
				original := "-" + token[offset:offset+1]
				flag, ok := canonical[original]
				if !ok {
					flag, ok = byAlias[original]
				}
				if !ok {
					interpreted = append(interpreted, "-"+token[offset:])
					return interpreted, spellings, occurrences, nil
				}
				spellings[flag.Name] = append(spellings[flag.Name], original)
				suffix := token[offset+1:]
				if flag.Boolean {
					if strings.HasPrefix(suffix, "=") {
						value := suffix[1:]
						interpreted = append(interpreted, "--"+flag.Name+"="+value)
						occurrences = append(occurrences, commandmeta.FlagOccurrence{Name: flag.Name, Spelling: original, RawValue: value})
						break
					}
					occurrences = append(occurrences, commandmeta.FlagOccurrence{Name: flag.Name, Spelling: original, RawValue: "true"})
					interpreted = append(interpreted, "--"+flag.Name)
					offset++
					continue
				}
				if suffix != "" {
					value := suffix
					if strings.HasPrefix(value, "=") {
						value = value[1:]
					}
					interpreted = append(interpreted, "--"+flag.Name+"="+value)
					occurrences = append(occurrences, commandmeta.FlagOccurrence{Name: flag.Name, Spelling: original, RawValue: value})
					break
				}
				if index+1 < len(argv) {
					value := argv[index+1]
					interpreted = append(interpreted, "--"+flag.Name+"="+value)
					occurrences = append(occurrences, commandmeta.FlagOccurrence{Name: flag.Name, Spelling: original, RawValue: value})
					index += 2
					consumedNext = true
					break
				}
				return interpreted, spellings, occurrences, &commandmeta.Failure{Message: fmt.Sprintf("flag needs an argument: %s", original)}
			}
			if !consumedNext {
				index++
			}
			continue
		}
		interpreted = append(interpreted, token)
		index++
	}
	return interpreted, spellings, occurrences, nil
}