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

package provider

import (
	"context"
	"encoding/json"
	"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/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              = &ServerTrafficBlockResource{}
	_ resource.ResourceWithConfigure = &ServerTrafficBlockResource{}
)

// NewServerTrafficBlockResource creates a new server traffic block resource.
func NewServerTrafficBlockResource() resource.Resource {
	return &ServerTrafficBlockResource{}
}

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

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

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

func (r *ServerTrafficBlockResource) Schema(_ context.Context, _ resource.SchemaRequest, resp *resource.SchemaResponse) {
	resp.Schema = schema.Schema{
		MarkdownDescription: "Manages a traffic block on a VirtFusion server.",
		Attributes: map[string]schema.Attribute{
			"id": schema.Int64Attribute{
				MarkdownDescription: "The identifier of the traffic block.",
				Computed:            true,
				PlanModifiers: []planmodifier.Int64{
					int64planmodifier.UseStateForUnknown(),
				},
			},
			"server_id": schema.Int64Attribute{
				MarkdownDescription: "The ID of the server to add the traffic block to.",
				Required:            true,
				PlanModifiers: []planmodifier.Int64{
					int64planmodifier.RequiresReplace(),
				},
			},
			"type": schema.StringAttribute{
				MarkdownDescription: "The type of traffic block (e.g. `inbound` or `outbound`).",
				Required:            true,
				PlanModifiers: []planmodifier.String{
					stringplanmodifier.RequiresReplace(),
				},
			},
		},
	}
}

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

	blockReq := client.TrafficBlockRequest{
		Type: data.Type.ValueString(),
	}

	apiPath := fmt.Sprintf("/servers/%d/traffic/blocks", data.ServerID.ValueInt64())
	respBody, err := r.client.Post(ctx, apiPath, blockReq)
	if err != nil {
		resp.Diagnostics.AddError(
			"Error Creating Traffic Block",
			fmt.Sprintf("Could not create traffic block on server %d: %s", data.ServerID.ValueInt64(), err),
		)
		return
	}

	var blockResp client.TrafficBlockResponse
	if err := json.Unmarshal(respBody, &blockResp); err != nil {
		resp.Diagnostics.AddError(
			"Error Parsing Response",
			fmt.Sprintf("Could not parse traffic block response: %s", err),
		)
		return
	}

	data.ID = types.Int64Value(blockResp.Data.ID)

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

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

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

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

	apiPath := fmt.Sprintf("/servers/%d/traffic/blocks/%d", data.ServerID.ValueInt64(), data.ID.ValueInt64())
	_, err := r.client.Delete(ctx, apiPath)
	if err != nil {
		var apiErr *client.APIError
		if errors.As(err, &apiErr) && apiErr.IsNotFound() {
			return
		}
		resp.Diagnostics.AddError(
			"Error Deleting Traffic Block",
			fmt.Sprintf("Could not delete traffic block %d on server %d: %s", data.ID.ValueInt64(), data.ServerID.ValueInt64(), err),
		)
		return
	}
}