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

package provider

import (
	"context"
	"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/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"
)

// Ensure provider-defined types fully satisfy framework interfaces.
var (
	_ resource.Resource              = &IPBlockRangeResource{}
	_ resource.ResourceWithConfigure = &IPBlockRangeResource{}
)

// NewIPBlockRangeResource creates a new IP block range resource.
func NewIPBlockRangeResource() resource.Resource {
	return &IPBlockRangeResource{}
}

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

// IPBlockRangeResourceModel describes the resource data model.
type IPBlockRangeResourceModel struct {
	ID        types.String `tfsdk:"id"`
	IPBlockID types.Int64  `tfsdk:"ip_block_id"`
	StartIP   types.String `tfsdk:"start_ip"`
	EndIP     types.String `tfsdk:"end_ip"`
	Gateway   types.String `tfsdk:"gateway"`
	Netmask   types.String `tfsdk:"netmask"`
}

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

func (r *IPBlockRangeResource) Schema(_ context.Context, _ resource.SchemaRequest, resp *resource.SchemaResponse) {
	resp.Schema = schema.Schema{
		MarkdownDescription: "Adds an IPv4 address range to a VirtFusion IP block. This is a create-only resource — ranges cannot be deleted via the API.",
		Attributes: map[string]schema.Attribute{
			"id": schema.StringAttribute{
				MarkdownDescription: "The identifier of the IP block range.",
				Computed:            true,
				PlanModifiers: []planmodifier.String{
					stringplanmodifier.UseStateForUnknown(),
				},
			},
			"ip_block_id": schema.Int64Attribute{
				MarkdownDescription: "The ID of the IP block to add the range to.",
				Required:            true,
				PlanModifiers: []planmodifier.Int64{
					int64planmodifier.RequiresReplace(),
				},
			},
			"start_ip": schema.StringAttribute{
				MarkdownDescription: "The starting IP address of the range.",
				Required:            true,
				PlanModifiers: []planmodifier.String{
					stringplanmodifier.RequiresReplace(),
				},
			},
			"end_ip": schema.StringAttribute{
				MarkdownDescription: "The ending IP address of the range.",
				Required:            true,
				PlanModifiers: []planmodifier.String{
					stringplanmodifier.RequiresReplace(),
				},
			},
			"gateway": schema.StringAttribute{
				MarkdownDescription: "The gateway address for the range.",
				Required:            true,
				PlanModifiers: []planmodifier.String{
					stringplanmodifier.RequiresReplace(),
				},
			},
			"netmask": schema.StringAttribute{
				MarkdownDescription: "The netmask for the range.",
				Required:            true,
				PlanModifiers: []planmodifier.String{
					stringplanmodifier.RequiresReplace(),
				},
			},
		},
	}
}

func (r *IPBlockRangeResource) 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. Please report this issue to the provider developers.", req.ProviderData),
		)
		return
	}

	r.client = c
}

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

	rangeReq := client.IPBlockRangeRequest{
		StartIP: data.StartIP.ValueString(),
		EndIP:   data.EndIP.ValueString(),
		Gateway: data.Gateway.ValueString(),
		Netmask: data.Netmask.ValueString(),
	}

	apiPath := fmt.Sprintf("/connectivity/ipblocks/%d/ipv4", data.IPBlockID.ValueInt64())
	_, err := r.client.Post(ctx, apiPath, rangeReq)
	if err != nil {
		resp.Diagnostics.AddError(
			"Error Creating IP Block Range",
			fmt.Sprintf("Could not create IP block range on block %d: %s", data.IPBlockID.ValueInt64(), err),
		)
		return
	}

	// Generate a composite ID since the API does not return one.
	data.ID = types.StringValue(fmt.Sprintf("%d/%s-%s", data.IPBlockID.ValueInt64(), data.StartIP.ValueString(), data.EndIP.ValueString()))

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

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

func (r *IPBlockRangeResource) Update(_ context.Context, _ resource.UpdateRequest, _ *resource.UpdateResponse) {
	// All attributes require replacement — updates are never called.
}

func (r *IPBlockRangeResource) Delete(_ context.Context, _ resource.DeleteRequest, _ *resource.DeleteResponse) {
	// No delete API — removing from state only.
}