package autofillcache

import (
	"encoding/json"
	"os"
	"path/filepath"
	"slices"
	"strings"
	"time"
)

type BindingsFile struct {
	UpdatedAt string            `json:"updatedAt"`
	Apps      map[string]string `json:"apps,omitempty"`
}

func ReadBindings(path string) (BindingsFile, error) {
	data, err := os.ReadFile(path)
	if err != nil {
		if os.IsNotExist(err) {
			return BindingsFile{}, nil
		}
		return BindingsFile{}, err
	}
	var bindings BindingsFile
	if err := json.Unmarshal(data, &bindings); err != nil {
		return BindingsFile{}, err
	}
	if bindings.Apps == nil {
		bindings.Apps = make(map[string]string)
	}
	return bindings, nil
}

func RememberBinding(path, rawTarget, entryID string, now time.Time) error {
	bindings, err := ReadBindings(path)
	if err != nil {
		return err
	}
	if bindings.Apps == nil {
		bindings.Apps = make(map[string]string)
	}
	target := strings.TrimSpace(rawTarget)
	id := strings.TrimSpace(entryID)
	if target == "" || id == "" {
		return nil
	}
	bindings.Apps[target] = id
	bindings.UpdatedAt = now.UTC().Format(time.RFC3339)
	data, err := json.MarshalIndent(bindings, "", "  ")
	if err != nil {
		return err
	}
	if err := os.MkdirAll(filepath.Dir(path), 0o755); err != nil {
		return err
	}
	return os.WriteFile(path, data, 0o600)
}

func ResolveWithBindings(cache File, bindings BindingsFile, rawTarget string) MatchResult {
	target := strings.TrimSpace(rawTarget)
	if entryID := strings.TrimSpace(bindings.Apps[target]); entryID != "" {
		for _, entry := range cache.Entries {
			if entry.ID == entryID {
				return MatchResult{Status: MatchStatusFound, Entry: entry}
			}
		}
	}
	return Resolve(cache, rawTarget)
}

func ChooserCandidates(cache File, rawTarget string) []Entry {
	if result := Resolve(cache, rawTarget); result.Status == MatchStatusFound {
		return []Entry{result.Entry}
	}
	candidates := append([]Entry(nil), cache.Entries...)
	slices.SortFunc(candidates, func(left, right Entry) int {
		if cmp := strings.Compare(strings.ToLower(strings.TrimSpace(left.Title)), strings.ToLower(strings.TrimSpace(right.Title))); cmp != 0 {
			return cmp
		}
		if cmp := strings.Compare(strings.ToLower(strings.Join(left.Path, "/")), strings.ToLower(strings.Join(right.Path, "/"))); cmp != 0 {
			return cmp
		}
		return strings.Compare(left.ID, right.ID)
	})
	return candidates
}