package main

import (
	"bytes"
	"context"
	"encoding/json"
	"fmt"
	"io"
	"net/http"

	"github.com/hashicorp/terraform-plugin-sdk/v2/diag"
	"github.com/hashicorp/terraform-plugin-sdk/v2/helper/schema"
)

// ClusterPayload represents the JSON body sent to /createcluster.
type ClusterPayload struct {
	Name            string `json:"Name"`
	ClusterID       string `json:"ClusterID"`
	ControlPlane    string `json:"ControlPlane"`
	Status          string `json:"Status"`
	Cpu             string `json:"Cpu"`
	Memory          string `json:"Memory"`
	PlatformVersion string `json:"PlatformVersion"`
	HealthCheck     string `json:"HealthCheck"`
	Alert           string `json:"Alert"`
	EndPoint        string `json:"EndPoint"`
	ClusterType     string `json:"ClusterType"`
	CoreDNSCpu      string `json:"CoreDNSCpu"`
	CoreDNSMemory   string `json:"CoreDNSMemory"`
	ApiServerCpu    string `json:"ApiServerCpu"`
	ApiServerMemory string `json:"ApiServerMemory"`
}

// resourceCluster defines the vcluster_cluster resource schema and CRUD.
func resourceCluster() *schema.Resource {
	return &schema.Resource{
		CreateContext: resourceClusterCreate,
		ReadContext:   resourceClusterRead,
		UpdateContext: resourceClusterUpdate,
		DeleteContext: resourceClusterDelete,

		Schema: map[string]*schema.Schema{
			"name":             {Type: schema.TypeString, Required: true},
			"cluster_id":       {Type: schema.TypeString, Required: true},
			"control_plane":    {Type: schema.TypeString, Required: true},
			"status":           {Type: schema.TypeString, Optional: true, Default: "Progressing"},
			"cpu":              {Type: schema.TypeString, Required: true},
			"memory":           {Type: schema.TypeString, Required: true},
			"platform_version": {Type: schema.TypeString, Required: true},
			"health_check":     {Type: schema.TypeString, Optional: true},
			"alert":            {Type: schema.TypeString, Optional: true},
			"endpoint":         {Type: schema.TypeString, Optional: true, Computed: true},
			"cluster_type":     {Type: schema.TypeString, Required: true},
			"coredns_cpu":      {Type: schema.TypeString, Required: true},
			"coredns_memory":   {Type: schema.TypeString, Required: true},
			"apiserver_cpu":    {Type: schema.TypeString, Required: true},
			"apiserver_memory": {Type: schema.TypeString, Required: true},
		},
	}
}

// buildPayload converts Terraform state to API payload.
func buildPayload(d *schema.ResourceData) ClusterPayload {
	return ClusterPayload{
		Name:            d.Get("name").(string),
		ClusterID:       d.Get("cluster_id").(string),
		ControlPlane:    d.Get("control_plane").(string),
		Status:          d.Get("status").(string),
		Cpu:             d.Get("cpu").(string),
		Memory:          d.Get("memory").(string),
		PlatformVersion: d.Get("platform_version").(string),
		HealthCheck:     d.Get("health_check").(string),
		Alert:           d.Get("alert").(string),
		EndPoint:        d.Get("endpoint").(string),
		ClusterType:     d.Get("cluster_type").(string),
		CoreDNSCpu:      d.Get("coredns_cpu").(string),
		CoreDNSMemory:   d.Get("coredns_memory").(string),
		ApiServerCpu:    d.Get("apiserver_cpu").(string),
		ApiServerMemory: d.Get("apiserver_memory").(string),
	}
}

// resourceClusterCreate calls POST /createcluster.
func resourceClusterCreate(ctx context.Context, d *schema.ResourceData, m interface{}) diag.Diagnostics {
	client, ok := m.(*apiClient)
	if !ok || client == nil {
		return diag.Errorf("invalid API client configuration")
	}

	payload := buildPayload(d)
	body, err := json.Marshal(payload)
	if err != nil {
		return diag.FromErr(err)
	}

	req, err := http.NewRequestWithContext(ctx, http.MethodPost, fmt.Sprintf("%s/createcluster", client.BaseURL), bytes.NewReader(body))
	if err != nil {
		return diag.FromErr(err)
	}
	req.Header.Set("Content-Type", "application/json")
	// Set Authorization header with raw token as provided by the login API usage.
	req.Header.Set("Authorization", client.Token)

	resp, err := http.DefaultClient.Do(req)
	if err != nil {
		return diag.FromErr(err)
	}
	defer resp.Body.Close()

	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
		b, _ := io.ReadAll(resp.Body)
		return diag.Errorf("createcluster failed: %s: %s", resp.Status, string(b))
	}

	// Use ClusterID as Terraform resource ID.
	d.SetId(payload.ClusterID)
	return resourceClusterRead(ctx, d, m)
}

// resourceClusterRead is a stub until a read API is available.
func resourceClusterRead(ctx context.Context, d *schema.ResourceData, m interface{}) diag.Diagnostics {
	// TODO: Implement GET call to sync state from API if/when available.
	return nil
}

// resourceClusterUpdate is a stub; you can extend it to call an update endpoint.
func resourceClusterUpdate(ctx context.Context, d *schema.ResourceData, m interface{}) diag.Diagnostics {
	// TODO: Implement update behavior when API supports it.
	return resourceClusterRead(ctx, d, m)
}

// resourceClusterDelete clears state; extend to call delete endpoint when available.
func resourceClusterDelete(ctx context.Context, d *schema.ResourceData, m interface{}) diag.Diagnostics {
	// TODO: Implement delete behavior when API supports it.
	d.SetId("")
	return nil
}