// Copyright (c) EZSCALE.
// SPDX-License-Identifier: MPL-2.0

package provider

import (
	"context"
	"errors"
	"fmt"

	"terraform-provider-virtfusion/internal/client"

	"github.com/hashicorp/terraform-plugin-framework/resource"
	"github.com/hashicorp/terraform-plugin-framework/resource/schema"
	"github.com/hashicorp/terraform-plugin-framework/resource/schema/int64default"
	"github.com/hashicorp/terraform-plugin-framework/resource/schema/int64planmodifier"
	"github.com/hashicorp/terraform-plugin-framework/resource/schema/planmodifier"
	"github.com/hashicorp/terraform-plugin-framework/resource/schema/stringplanmodifier"
	"github.com/hashicorp/terraform-plugin-framework/types"
)

var (
	_ resource.Resource              = &ServerIPv4Resource{}
	_ resource.ResourceWithConfigure = &ServerIPv4Resource{}
)

// NewServerIPv4Resource returns a new resource for managing server IPv4 addresses.
func NewServerIPv4Resource() resource.Resource {
	return &ServerIPv4Resource{}
}

// ServerIPv4Resource defines the resource implementation.
type ServerIPv4Resource struct {
	client *client.Client
}

// ServerIPv4ResourceModel describes the resource data model.
type ServerIPv4ResourceModel struct {
	ID       types.String `tfsdk:"id"`
	ServerID types.Int64  `tfsdk:"server_id"`
	Quantity types.Int64  `tfsdk:"quantity"`
}

func (r *ServerIPv4Resource) Metadata(_ context.Context, req resource.MetadataRequest, resp *resource.MetadataResponse) {
	resp.TypeName = req.ProviderTypeName + "_server_ipv4"
}

func (r *ServerIPv4Resource) Schema(_ context.Context, _ resource.SchemaRequest, resp *resource.SchemaResponse) {
	resp.Schema = schema.Schema{
		MarkdownDescription: "Adds IPv4 addresses to a VirtFusion server.",
		Attributes: map[string]schema.Attribute{
			"id": schema.StringAttribute{
				MarkdownDescription: "Resource identifier.",
				Computed:            true,
				PlanModifiers: []planmodifier.String{
					stringplanmodifier.UseStateForUnknown(),
				},
			},
			"server_id": schema.Int64Attribute{
				MarkdownDescription: "The ID of the server. Changing this forces a new resource to be created.",
				Required:            true,
				PlanModifiers: []planmodifier.Int64{
					int64planmodifier.RequiresReplace(),
				},
			},
			"quantity": schema.Int64Attribute{
				MarkdownDescription: "The number of IPv4 addresses to add. Defaults to `1`. Changing this forces a new resource to be created.",
				Optional:            true,
				Computed:            true,
				Default:             int64default.StaticInt64(1),
				PlanModifiers: []planmodifier.Int64{
					int64planmodifier.RequiresReplace(),
				},
			},
		},
	}
}

func (r *ServerIPv4Resource) Configure(_ context.Context, req resource.ConfigureRequest, resp *resource.ConfigureResponse) {
	if req.ProviderData == nil {
		return
	}

	c, ok := req.ProviderData.(*client.Client)
	if !ok {
		resp.Diagnostics.AddError(
			"Unexpected Resource Configure Type",
			fmt.Sprintf("Expected *client.Client, got: %T.", req.ProviderData),
		)
		return
	}

	r.client = c
}

func (r *ServerIPv4Resource) Create(ctx context.Context, req resource.CreateRequest, resp *resource.CreateResponse) {
	var data ServerIPv4ResourceModel
	resp.Diagnostics.Append(req.Plan.Get(ctx, &data)...)
	if resp.Diagnostics.HasError() {
		return
	}

	serverID := data.ServerID.ValueInt64()
	quantity := data.Quantity.ValueInt64()

	var body interface{}
	if quantity > 1 {
		body = client.ServerIPv4AddRequest{
			Quantity: quantity,
		}
	}

	_, err := r.client.Post(ctx, fmt.Sprintf("/servers/%d/ipv4", serverID), body)
	if err != nil {
		resp.Diagnostics.AddError("Error adding IPv4 to server", err.Error())
		return
	}

	data.ID = types.StringValue(fmt.Sprintf("%d/ipv4/%d", serverID, quantity))

	resp.Diagnostics.Append(resp.State.Set(ctx, &data)...)
}

func (r *ServerIPv4Resource) Read(ctx context.Context, req resource.ReadRequest, resp *resource.ReadResponse) {
	var data ServerIPv4ResourceModel
	resp.Diagnostics.Append(req.State.Get(ctx, &data)...)
	if resp.Diagnostics.HasError() {
		return
	}

	// No dedicated read endpoint; return stored state as-is.
	resp.Diagnostics.Append(resp.State.Set(ctx, &data)...)
}

func (r *ServerIPv4Resource) Update(_ context.Context, _ resource.UpdateRequest, resp *resource.UpdateResponse) {
	// All attributes have RequiresReplace, so Update should never be called.
	resp.Diagnostics.AddError(
		"Update Not Supported",
		"All attributes of virtfusion_server_ipv4 require replacement. This function should not be called.",
	)
}

func (r *ServerIPv4Resource) Delete(ctx context.Context, req resource.DeleteRequest, resp *resource.DeleteResponse) {
	var data ServerIPv4ResourceModel
	resp.Diagnostics.Append(req.State.Get(ctx, &data)...)
	if resp.Diagnostics.HasError() {
		return
	}

	serverID := data.ServerID.ValueInt64()

	_, err := r.client.Delete(ctx, fmt.Sprintf("/servers/%d/ipv4", serverID))
	if err != nil {
		var apiErr *client.APIError
		if errors.As(err, &apiErr) && apiErr.IsNotFound() {
			return
		}
		resp.Diagnostics.AddError("Error removing IPv4 from server", err.Error())
	}
}