// Package docs — генерация ops-документации.
package docs

import (
	"encoding/json"
	"fmt"
	"os"
	"strings"

	"ops-generator/internal/types"
)

// Entry — запись в индексе документации.
type Entry struct {
	ServiceID int
	Name      string
	File      string
	Title     string
	OpCount   int
}

// ServiceDoc генерирует Markdown-документацию операций сервиса.
func ServiceDoc(path string, spec types.ServiceOpsSpec) error {
	var b strings.Builder
	b.WriteString(fmt.Sprintf("# Operations for nubes_%s\n\n", spec.Name))
	b.WriteString(fmt.Sprintf("Service ID: `%d`\n\n", spec.ServiceID))

	if t := Title(spec); t != "" {
		b.WriteString(fmt.Sprintf("Service: %s\n\n", t))
	}

	if strings.TrimSpace(spec.ServiceMan) != "" {
		b.WriteString("## UI description\n\n")
		b.WriteString(spec.ServiceMan)
		b.WriteString("\n\n")
	}

	b.WriteString("## Operations\n\n")
	b.WriteString("Non-CRUD operations are typically executed via an action resource.\n")
	b.WriteString("Domain operations (for example create_user, create_database) are best modeled as separate resources.\n\n")
	if len(spec.Operations) == 0 {
		b.WriteString("No operations found.\n")
		return os.WriteFile(path, []byte(b.String()), 0o644)
	}

	for _, op := range spec.Operations {
		b.WriteString(fmt.Sprintf("- `%s` (id: %d)\n", op.Name, op.ID))
	}
	b.WriteString("\n")

	for _, op := range spec.Operations {
		b.WriteString(fmt.Sprintf("## Operation: %s\n\n", op.Name))
		b.WriteString(fmt.Sprintf("Operation ID: `%d`\n\n", op.ID))
		if strings.TrimSpace(op.Man) != "" {
			b.WriteString(op.Man)
			b.WriteString("\n\n")
		}
		if len(op.Params) == 0 {
			b.WriteString("No parameters.\n\n")
			continue
		}

		b.WriteString("| Code | Type | Required | Default | ID | RefSvcId | ValueList | Func | Regex | Min | Max | Sensitive | DependsOn |\n")
		b.WriteString("|---|---|---|---|---|---|---|---|---|---|---|---|---|\n")
		for _, p := range op.Params {
			b.WriteString(fmt.Sprintf("| `%s` | `%s` | `%t` | `%s` | `%d` | `%s` | `%s` | `%s` | `%s` | `%s` | `%s` | `%t` | `%s` |\n",
				Esc(p.Code),
				Esc(p.DataType),
				p.Required,
				Esc(Value(p.Default)),
				p.ID,
				Esc(Ref(p.RefSvcId)),
				Esc(List(p.ValueList)),
				Esc(p.Func),
				Esc(p.Regex),
				Esc(Value(p.MinValue)),
				Esc(Value(p.MaxValue)),
				p.IsSensitive,
				Esc(Value(p.DependsOn)),
			))
		}
		b.WriteString("\n")
	}

	return os.WriteFile(path, []byte(b.String()), 0o644)
}

// Index генерирует index.md со списком всех операций.
func Index(path string, entries []Entry) error {
	var b strings.Builder
	b.WriteString("# Operations by service\n\n")
	b.WriteString("Auto-generated list of available operations per service.\n\n")
	b.WriteString("Note: non-CRUD operations should be invoked via an action resource,\n")
	b.WriteString("and domain operations are best represented as dedicated resources.\n\n")
	for _, e := range entries {
		b.WriteString(fmt.Sprintf("- %d - nubes_%s (%d ops): [%s](%s)\n", e.ServiceID, e.Name, e.OpCount, e.Title, e.File))
	}
	return os.WriteFile(path, []byte(b.String()), 0o644)
}

// Name нормализует имя файла.
func Name(name string) string {
	name = strings.ToLower(strings.TrimSpace(name))
	name = strings.ReplaceAll(name, " ", "_")
	name = strings.ReplaceAll(name, "/", "_")
	name = strings.ReplaceAll(name, "\\", "_")
	name = strings.ReplaceAll(name, ":", "_")
	name = strings.ReplaceAll(name, "-", "_")
	return name
}

// Title возвращает отображаемое имя сервиса.
func Title(spec types.ServiceOpsSpec) string {
	if strings.TrimSpace(spec.ServiceDisplayName) != "" {
		return spec.ServiceDisplayName
	}
	if strings.TrimSpace(spec.ServiceShortName) != "" {
		return spec.ServiceShortName
	}
	return ""
}

// List форматирует список значений.
func List(items []string) string {
	if len(items) == 0 {
		return ""
	}
	return strings.Join(items, ",")
}

// Ref форматирует RefSvcId.
func Ref(value *int) string {
	if value == nil {
		return ""
	}
	return fmt.Sprintf("%d", *value)
}

// Value форматирует значение параметра.
func Value(value interface{}) string {
	if value == nil {
		return ""
	}
	switch t := value.(type) {
	case string:
		return t
	default:
		b, err := json.Marshal(t)
		if err != nil {
			return fmt.Sprintf("%v", value)
		}
		return string(b)
	}
}

// Esc экранирует pipe-символы для Markdown-таблиц.
func Esc(value string) string {
	return strings.ReplaceAll(value, "|", "\\|")
}