// 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/float64planmodifier"
	"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              = &SelfServiceCreditResource{}
	_ resource.ResourceWithConfigure = &SelfServiceCreditResource{}
)

// NewSelfServiceCreditResource creates a new self-service credit resource.
func NewSelfServiceCreditResource() resource.Resource {
	return &SelfServiceCreditResource{}
}

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

// SelfServiceCreditResourceModel describes the resource data model.
type SelfServiceCreditResourceModel struct {
	ID           types.Int64   `tfsdk:"id"`
	Amount       types.Float64 `tfsdk:"amount"`
	CurrencyCode types.String  `tfsdk:"currency_code"`
	UserID       types.Int64   `tfsdk:"user_id"`
}

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

func (r *SelfServiceCreditResource) Schema(_ context.Context, _ resource.SchemaRequest, resp *resource.SchemaResponse) {
	resp.Schema = schema.Schema{
		MarkdownDescription: "Manages self-service credit in VirtFusion. Deleting this resource cancels the credit.",
		Attributes: map[string]schema.Attribute{
			"id": schema.Int64Attribute{
				MarkdownDescription: "The identifier of the credit entry.",
				Computed:            true,
				PlanModifiers: []planmodifier.Int64{
					int64planmodifier.UseStateForUnknown(),
				},
			},
			"amount": schema.Float64Attribute{
				MarkdownDescription: "The credit amount.",
				Required:            true,
				PlanModifiers: []planmodifier.Float64{
					float64planmodifier.RequiresReplace(),
				},
			},
			"currency_code": schema.StringAttribute{
				MarkdownDescription: "The currency code (e.g. `USD`, `EUR`).",
				Required:            true,
				PlanModifiers: []planmodifier.String{
					stringplanmodifier.RequiresReplace(),
				},
			},
			"user_id": schema.Int64Attribute{
				MarkdownDescription: "The ID of the user to add credit to.",
				Required:            true,
				PlanModifiers: []planmodifier.Int64{
					int64planmodifier.RequiresReplace(),
				},
			},
		},
	}
}

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

	creditReq := client.SelfServiceCreditRequest{
		Amount:       data.Amount.ValueFloat64(),
		CurrencyCode: data.CurrencyCode.ValueString(),
		UserID:       data.UserID.ValueInt64(),
	}

	respBody, err := r.client.Post(ctx, "/selfService/credit", creditReq)
	if err != nil {
		resp.Diagnostics.AddError(
			"Error Creating Credit",
			fmt.Sprintf("Could not create credit for user %d: %s", data.UserID.ValueInt64(), err),
		)
		return
	}

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

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

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

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

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

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

	apiPath := fmt.Sprintf("/selfService/credit/%d", 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 Cancelling Credit",
			fmt.Sprintf("Could not cancel credit %d: %s", data.ID.ValueInt64(), err),
		)
		return
	}
}