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

package provider

import (
	"context"
	"encoding/json"
	"errors"
	"fmt"
	"strconv"

	"terraform-provider-virtfusion/internal/client"

	"github.com/hashicorp/terraform-plugin-framework/path"
	"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                = &SSHKeyResource{}
	_ resource.ResourceWithConfigure   = &SSHKeyResource{}
	_ resource.ResourceWithImportState = &SSHKeyResource{}
)

// NewSSHKeyResource creates a new SSH key resource.
func NewSSHKeyResource() resource.Resource {
	return &SSHKeyResource{}
}

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

// SSHKeyResourceModel describes the resource data model.
type SSHKeyResourceModel struct {
	ID        types.Int64  `tfsdk:"id"`
	UserID    types.Int64  `tfsdk:"user_id"`
	Name      types.String `tfsdk:"name"`
	PublicKey types.String `tfsdk:"public_key"`
}

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

func (r *SSHKeyResource) Schema(_ context.Context, _ resource.SchemaRequest, resp *resource.SchemaResponse) {
	resp.Schema = schema.Schema{
		MarkdownDescription: "Manages a VirtFusion SSH key.",
		Attributes: map[string]schema.Attribute{
			"id": schema.Int64Attribute{
				MarkdownDescription: "The ID of the SSH key.",
				Computed:            true,
				PlanModifiers: []planmodifier.Int64{
					int64planmodifier.UseStateForUnknown(),
				},
			},
			"user_id": schema.Int64Attribute{
				MarkdownDescription: "The ID of the user who owns this SSH key.",
				Required:            true,
				PlanModifiers: []planmodifier.Int64{
					int64planmodifier.RequiresReplace(),
				},
			},
			"name": schema.StringAttribute{
				MarkdownDescription: "The name of the SSH key.",
				Required:            true,
				PlanModifiers: []planmodifier.String{
					stringplanmodifier.RequiresReplace(),
				},
			},
			"public_key": schema.StringAttribute{
				MarkdownDescription: "The public key content.",
				Required:            true,
				PlanModifiers: []planmodifier.String{
					stringplanmodifier.RequiresReplace(),
				},
			},
		},
	}
}

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

	createReq := client.SSHKeyCreateRequest{
		UserID:    data.UserID.ValueInt64(),
		Name:      data.Name.ValueString(),
		PublicKey: data.PublicKey.ValueString(),
	}

	respBody, err := r.client.Post(ctx, "/ssh_keys", createReq)
	if err != nil {
		resp.Diagnostics.AddError(
			"Error Creating SSH Key",
			fmt.Sprintf("Could not create SSH key: %s", err),
		)
		return
	}

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

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

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

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

	apiPath := fmt.Sprintf("/ssh_keys/%d", data.ID.ValueInt64())
	respBody, err := r.client.Get(ctx, apiPath)
	if err != nil {
		var apiErr *client.APIError
		if errors.As(err, &apiErr) && apiErr.IsNotFound() {
			// SSH key no longer exists, remove from state.
			resp.State.RemoveResource(ctx)
			return
		}

		resp.Diagnostics.AddError(
			"Error Reading SSH Key",
			fmt.Sprintf("Could not read SSH key %d: %s", data.ID.ValueInt64(), err),
		)
		return
	}

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

	// Update state from API response.
	data.Name = types.StringValue(sshKeyResp.Data.Name)

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

func (r *SSHKeyResource) Update(ctx context.Context, req resource.UpdateRequest, resp *resource.UpdateResponse) {
	var data SSHKeyResourceModel
	resp.Diagnostics.Append(req.Plan.Get(ctx, &data)...)
	if resp.Diagnostics.HasError() {
		return
	}

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

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

	apiPath := fmt.Sprintf("/ssh_keys/%d", data.ID.ValueInt64())
	_, err := r.client.Delete(ctx, apiPath)
	if err != nil {
		var apiErr *client.APIError
		if errors.As(err, &apiErr) && apiErr.IsNotFound() {
			// Already deleted, nothing to do.
			return
		}

		resp.Diagnostics.AddError(
			"Error Deleting SSH Key",
			fmt.Sprintf("Could not delete SSH key %d: %s", data.ID.ValueInt64(), err),
		)
		return
	}
}

func (r *SSHKeyResource) ImportState(ctx context.Context, req resource.ImportStateRequest, resp *resource.ImportStateResponse) {
	id, err := strconv.ParseInt(req.ID, 10, 64)
	if err != nil {
		resp.Diagnostics.AddError(
			"Invalid Import ID",
			fmt.Sprintf("Could not parse SSH key ID %q as integer: %s", req.ID, err),
		)
		return
	}

	resp.Diagnostics.Append(resp.State.SetAttribute(ctx, path.Root("id"), types.Int64Value(id))...)
}