/*
Copyright 2024 The Cozystack Authors.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package config

import (
	"fmt"
	"os"

	"gopkg.in/yaml.v2"
)

// ResourceConfig represents the structure of the configuration file.
type ResourceConfig struct {
	Resources []Resource `yaml:"resources"`
}

// Resource describes an individual resource.
type Resource struct {
	Application ApplicationConfig `yaml:"application"`
	Release     ReleaseConfig     `yaml:"release"`
}

// ApplicationConfig contains the application settings.
type ApplicationConfig struct {
	Kind       string   `yaml:"kind"`
	Singular   string   `yaml:"singular"`
	Plural     string   `yaml:"plural"`
	ShortNames []string `yaml:"shortNames"`
}

// ReleaseConfig contains the release settings.
type ReleaseConfig struct {
	Prefix string            `yaml:"prefix"`
	Labels map[string]string `yaml:"labels"`
	Chart  ChartConfig       `yaml:"chart"`
}

// ChartConfig contains the chart settings.
type ChartConfig struct {
	Name      string          `yaml:"name"`
	SourceRef SourceRefConfig `yaml:"sourceRef"`
}

// SourceRefConfig contains the reference to the chart source.
type SourceRefConfig struct {
	Kind      string `yaml:"kind"`
	Name      string `yaml:"name"`
	Namespace string `yaml:"namespace"`
}

// LoadConfig loads the configuration from the specified path and validates it.
func LoadConfig(path string) (*ResourceConfig, error) {
	data, err := os.ReadFile(path)
	if err != nil {
		return nil, err
	}

	var config ResourceConfig
	if err := yaml.Unmarshal(data, &config); err != nil {
		return nil, err
	}

	// Validate the configuration.
	for i, res := range config.Resources {
		if res.Application.Kind == "" {
			return nil, fmt.Errorf("resource at index %d has an empty kind", i)
		}
		if res.Application.Plural == "" {
			return nil, fmt.Errorf("resource at index %d has an empty plural", i)
		}
		if res.Release.Chart.Name == "" {
			return nil, fmt.Errorf("resource at index %d has an empty chart name in release", i)
		}
		if res.Release.Chart.SourceRef.Kind == "" || res.Release.Chart.SourceRef.Name == "" || res.Release.Chart.SourceRef.Namespace == "" {
			return nil, fmt.Errorf("resource at index %d has an incomplete sourceRef for chart in release", i)
		}
	}
	return &config, nil
}