// Copyright (c) Tailscale Inc & AUTHORS
// SPDX-License-Identifier: BSD-3-Clause

// Package policytest contains test helpers for the syspolicy packages.
package policytest

import (
	"fmt"
	"time"

	"tailscale.com/util/syspolicy/pkey"
	"tailscale.com/util/syspolicy/policyclient"
	"tailscale.com/util/syspolicy/ptype"
)

// Config is a [policyclient.Client] implementation with a static mapping of
// values.
//
// It is used for testing purposes to simulate policy client behavior.
//
// It panics if a value is Set with one type and then accessed with a different
// expected type and/or value. Some accessors such as GetPreferenceOption and
// GetVisibility support either a ptype.PreferenceOption/ptype.Visibility in the
// map, or the string representation as supported by their UnmarshalText
// methods.
//
// The map value may be an error to return that error value from the accessor.
type Config map[pkey.Key]any

var _ policyclient.Client = Config{}

func (c *Config) Set(key pkey.Key, value any) {
	if *c == nil {
		*c = make(map[pkey.Key]any)
	}
	(*c)[key] = value
}

func (c Config) GetStringArray(key pkey.Key, defaultVal []string) ([]string, error) {
	if val, ok := c[key]; ok {
		switch val := val.(type) {
		case []string:
			return val, nil
		case error:
			return nil, val
		default:
			panic(fmt.Sprintf("key %s is not a []string; got %T", key, val))
		}
	}
	return defaultVal, nil
}

func (c Config) GetString(key pkey.Key, defaultVal string) (string, error) {
	if val, ok := c[key]; ok {
		switch val := val.(type) {
		case string:
			return val, nil
		case error:
			return "", val
		default:
			panic(fmt.Sprintf("key %s is not a string; got %T", key, val))
		}
	}
	return defaultVal, nil
}

func (c Config) GetBoolean(key pkey.Key, defaultVal bool) (bool, error) {
	if val, ok := c[key]; ok {
		switch val := val.(type) {
		case bool:
			return val, nil
		case error:
			return false, val
		default:
			panic(fmt.Sprintf("key %s is not a bool; got %T", key, val))
		}
	}
	return defaultVal, nil
}

func (c Config) GetUint64(key pkey.Key, defaultVal uint64) (uint64, error) {
	if val, ok := c[key]; ok {
		switch val := val.(type) {
		case uint64:
			return val, nil
		case error:
			return 0, val
		default:
			panic(fmt.Sprintf("key %s is not a uint64; got %T", key, val))
		}
	}
	return defaultVal, nil
}

func (c Config) GetDuration(key pkey.Key, defaultVal time.Duration) (time.Duration, error) {
	if val, ok := c[key]; ok {
		switch val := val.(type) {
		case time.Duration:
			return val, nil
		case error:
			return 0, val
		default:
			panic(fmt.Sprintf("key %s is not a time.Duration; got %T", key, val))
		}
	}
	return defaultVal, nil
}

func (c Config) GetPreferenceOption(key pkey.Key, defaultVal ptype.PreferenceOption) (ptype.PreferenceOption, error) {
	if val, ok := c[key]; ok {
		switch val := val.(type) {
		case ptype.PreferenceOption:
			return val, nil
		case error:
			var zero ptype.PreferenceOption
			return zero, val
		case string:
			var p ptype.PreferenceOption
			err := p.UnmarshalText(([]byte)(val))
			return p, err
		default:
			panic(fmt.Sprintf("key %s is not a ptype.PreferenceOption", key))
		}
	}
	return defaultVal, nil
}

func (c Config) GetVisibility(key pkey.Key) (ptype.Visibility, error) {
	if val, ok := c[key]; ok {
		switch val := val.(type) {
		case ptype.Visibility:
			return val, nil
		case error:
			var zero ptype.Visibility
			return zero, val
		case string:
			var p ptype.Visibility
			err := p.UnmarshalText(([]byte)(val))
			return p, err
		default:
			panic(fmt.Sprintf("key %s is not a ptype.Visibility", key))
		}
	}
	return ptype.Visibility(ptype.ShowChoiceByPolicy), nil
}

func (c Config) HasAnyOf(keys ...pkey.Key) (bool, error) {
	for _, key := range keys {
		if _, ok := c[key]; ok {
			return true, nil
		}
	}
	return false, nil
}

func (sp Config) RegisterChangeCallback(callback func(policyclient.PolicyChange)) (func(), error) {
	return func() {}, nil
}

func (sp Config) SetDebugLoggingEnabled(enabled bool) {}