// Copyright (c) STACKIT

package foo

import (
	"context"
	"fmt"
	"strings"

	"github.com/hashicorp/terraform-plugin-framework/resource"
	"github.com/hashicorp/terraform-plugin-framework/resource/schema"
	"github.com/hashicorp/terraform-plugin-framework/resource/schema/planmodifier"
	"github.com/hashicorp/terraform-plugin-framework/resource/schema/stringplanmodifier"
	"github.com/hashicorp/terraform-plugin-framework/schema/validator"
	"github.com/hashicorp/terraform-plugin-framework/types"
	"github.com/hashicorp/terraform-plugin-log/tflog"
	"github.com/mhenselin/terraform-provider-stackitprivatepreview/stackit/internal/conversion"
	"github.com/mhenselin/terraform-provider-stackitprivatepreview/stackit/internal/core"
	fooUtils "github.com/mhenselin/terraform-provider-stackitprivatepreview/stackit/internal/services/foo/utils"
	"github.com/mhenselin/terraform-provider-stackitprivatepreview/stackit/internal/utils"

	"github.com/stackitcloud/stackit-sdk-go/services/foo"      // Import service "foo" from the STACKIT SDK for Go
	"github.com/stackitcloud/stackit-sdk-go/services/foo/wait" // Import service "foo" waiters from the STACKIT SDK for Go (in case the service API has asynchronous endpoints)
	// (...)
)

// Ensure the implementation satisfies the expected interfaces.
var (
	_ resource.Resource                = &barResource{}
	_ resource.ResourceWithConfigure   = &barResource{}
	_ resource.ResourceWithImportState = &barResource{}
	_ resource.ResourceWithModifyPlan  = &barResource{} // not needed for global APIs
)

// Model is the internal model of the terraform resource
type Model struct {
	Id              types.String `tfsdk:"id"` // needed by TF
	ProjectId       types.String `tfsdk:"project_id"`
	BarId           types.String `tfsdk:"bar_id"`
	Region          types.String `tfsdk:"region"`
	MyRequiredField types.String `tfsdk:"my_required_field"`
	MyOptionalField types.String `tfsdk:"my_optional_field"`
	MyReadOnlyField types.String `tfsdk:"my_read_only_field"`
}

// NewBarResource is a helper function to simplify the provider implementation.
func NewBarResource() resource.Resource {
	return &barResource{}
}

// barResource is the resource implementation.
type barResource struct {
	client       *foo.APIClient
	providerData core.ProviderData // not needed for global APIs
}

// Metadata returns the resource type name.
func (r *barResource) Metadata(_ context.Context, req resource.MetadataRequest, resp *resource.MetadataResponse) {
	resp.TypeName = req.ProviderTypeName + "_foo_bar"
}

// ModifyPlan implements resource.ResourceWithModifyPlan.
// Use the modifier to set the effective region in the current plan. - FYI: This isn't needed for global APIs.
func (r *barResource) ModifyPlan(ctx context.Context, req resource.ModifyPlanRequest, resp *resource.ModifyPlanResponse) { // nolint:gocritic // function signature required by Terraform
	// FYI: the ModifyPlan implementation is not needed for global APIs
	var configModel Model
	// skip initial empty configuration to avoid follow-up errors
	if req.Config.Raw.IsNull() {
		return
	}
	resp.Diagnostics.Append(req.Config.Get(ctx, &configModel)...)
	if resp.Diagnostics.HasError() {
		return
	}

	var planModel Model
	resp.Diagnostics.Append(req.Plan.Get(ctx, &planModel)...)
	if resp.Diagnostics.HasError() {
		return
	}

	utils.AdaptRegion(ctx, configModel.Region, &planModel.Region, r.providerData.GetRegion(), resp)
	if resp.Diagnostics.HasError() {
		return
	}

	resp.Diagnostics.Append(resp.Plan.Set(ctx, planModel)...)
	if resp.Diagnostics.HasError() {
		return
	}
}

// Configure adds the provider configured client to the resource.
func (r *barResource) Configure(ctx context.Context, req resource.ConfigureRequest, resp *resource.ConfigureResponse) {
	providerData, ok := conversion.ParseProviderData(ctx, req.ProviderData, &resp.Diagnostics)
	if !ok {
		return
	}

	apiClient := fooUtils.ConfigureClient(ctx, &providerData, &resp.Diagnostics)
	if resp.Diagnostics.HasError() {
		return
	}
	r.client = apiClient
	tflog.Info(ctx, "Foo bar client configured")
}

// Schema defines the schema for the resource.
func (r *barResource) Schema(_ context.Context, _ resource.SchemaRequest, resp *resource.SchemaResponse) {
	descriptions := map[string]string{
		"main":               "Foo bar resource schema.",
		"id":                 "Terraform's internal resource identifier. It is structured as \"`project_id`,`bar_id`\".",
		"project_id":         "STACKIT Project ID to which the bar is associated.",
		"bar_id":             "The bar ID.",
		"region":             "The resource region. If not defined, the provider region is used.",
		"my_required_field":  "My required field description.",
		"my_optional_field":  "My optional field description.",
		"my_read_only_field": "My read-only field description.",
	}

	resp.Schema = schema.Schema{
		Description: descriptions["main"],
		Attributes: map[string]schema.Attribute{
			"id": schema.StringAttribute{
				Description: descriptions["id"],
				Computed:    true,
				PlanModifiers: []planmodifier.String{
					stringplanmodifier.UseStateForUnknown(),
				},
			},
			"project_id": schema.StringAttribute{
				Description: descriptions["project_id"],
				Required:    true,
				PlanModifiers: []planmodifier.String{
					// "RequiresReplace" makes the provider recreate the resource when the field is changed in the configuration
					stringplanmodifier.RequiresReplace(),
				},
				Validators: []validator.String{
					// Validators can be used to validate the values set to a field
					validate.UUID(),
					validate.NoSeparator(),
				},
			},
			"bar_id": schema.StringAttribute{
				Description: descriptions["bar_id"],
				Computed:    true,
			},
			"region": schema.StringAttribute{ // not needed for global APIs
				Optional: true,
				// must be computed to allow for storing the override value from the provider
				Computed:    true,
				Description: descriptions["region"],
				PlanModifiers: []planmodifier.String{
					stringplanmodifier.RequiresReplace(),
				},
			},
			"my_required_field": schema.StringAttribute{
				Description: descriptions["my_required_field"],
				Required:    true,
				PlanModifiers: []planmodifier.String{
					// "RequiresReplace" makes the provider recreate the resource when the field is changed in the configuration
					stringplanmodifier.RequiresReplace(),
				},
			},
			"my_optional_field": schema.StringAttribute{
				Description: descriptions["my_optional_field"],
				Optional:    true,
				Computed:    true,
				PlanModifiers: []planmodifier.String{
					// "UseStateForUnknown" can be used to copy a prior state value into the planned value. It should be used when it is known that an unconfigured value will remain the same after a resource update
					stringplanmodifier.UseStateForUnknown(),
				},
			},
			"my_read_only_field": schema.StringAttribute{
				Description: descriptions["my_read_only_field"],
				Computed:    true,
			},
		},
	}
}

// Create creates the resource and sets the initial Terraform state.
func (r *barResource) Create(ctx context.Context, req resource.CreateRequest, resp *resource.CreateResponse) { // nolint:gocritic // function signature required by Terraform
	var model Model
	resp.Diagnostics.Append(req.Plan.Get(ctx, &model)...)
	if resp.Diagnostics.HasError() {
		return
	}

	ctx = core.InitProviderContext(ctx)

	projectId := model.ProjectId.ValueString()
	region := model.Region.ValueString() // not needed for global APIs
	ctx = tflog.SetField(ctx, "project_id", projectId)
	ctx = tflog.SetField(ctx, "region", region)

	// prepare the payload struct for the create bar request
	payload, err := toCreatePayload(&model)
	if err != nil {
		core.LogAndAddError(ctx, &resp.Diagnostics, "Error creating credential", fmt.Sprintf("Creating API payload: %v", err))
		return
	}

	// Create new bar
	barResp, err := r.client.CreateBar(ctx, projectId, region).CreateBarPayload(*payload).Execute()
	if err != nil {
		core.LogAndAddError(ctx, &resp.Diagnostics, "Error creating bar", fmt.Sprintf("Calling API: %v", err))
		return
	}

	ctx = core.LogResponse(ctx)

	// only in case the create bar API call is asynchronous (Make sure to include *ALL* fields which are part of the
	// internal terraform resource id! And please include the comment below in your code):
	// Write id attributes to state before polling via the wait handler - just in case anything goes wrong during the wait handler
	ctx = utils.SetAndLogStateFields(ctx, &resp.Diagnostics, &resp.State, map[string]interface{}{
		"project_id": projectId,
		"region":     region,
		"bar_id":     resp.BarId,
	})
	if resp.Diagnostics.HasError() {
		return
	}
	// only in case the create bar API request is synchronous: just log the bar id field instead
	ctx = tflog.SetField(ctx, "bar_id", resp.BarId)

	// only in case the create bar API call is asynchronous: use a wait handler to wait for the create process to complete
	barResp, err := wait.CreateBarWaitHandler(ctx, r.client, projectId, region, resp.BarId).WaitWithContext(ctx)
	if err != nil {
		core.LogAndAddError(ctx, &resp.Diagnostics, "Error creating bar", fmt.Sprintf("Bar creation waiting: %v", err))
		return
	}

	// No matter if the API request is synchronous or asynchronous: Map response body to schema
	err = mapFields(resp, &model)
	if err != nil {
		core.LogAndAddError(ctx, &resp.Diagnostics, "Error creating bar", fmt.Sprintf("Processing API payload: %v", err))
		return
	}
	resp.Diagnostics.Append(resp.State.Set(ctx, model)...)
	if resp.Diagnostics.HasError() {
		return
	}
	tflog.Info(ctx, "Foo bar created")
}

// Read refreshes the Terraform state with the latest data.
func (r *barResource) Read(ctx context.Context, req resource.ReadRequest, resp *resource.ReadResponse) { // nolint:gocritic // function signature required by Terraform
	var model Model
	resp.Diagnostics.Append(req.State.Get(ctx, &model)...)
	if resp.Diagnostics.HasError() {
		return
	}

	ctx = core.InitProviderContext(ctx)

	projectId := model.ProjectId.ValueString()
	region := r.providerData.GetRegionWithOverride(model.Region)
	barId := model.BarId.ValueString()
	ctx = tflog.SetField(ctx, "project_id", projectId)
	ctx = tflog.SetField(ctx, "region", region)
	ctx = tflog.SetField(ctx, "bar_id", barId)

	barResp, err := r.client.GetBar(ctx, projectId, region, barId).Execute()
	if err != nil {
		core.LogAndAddError(ctx, &resp.Diagnostics, "Error reading bar", fmt.Sprintf("Calling API: %v", err))
		return
	}

	ctx = core.LogResponse(ctx)

	// Map response body to schema
	err = mapFields(barResp, &model)
	if err != nil {
		core.LogAndAddError(ctx, &resp.Diagnostics, "Error reading bar", fmt.Sprintf("Processing API payload: %v", err))
		return
	}

	// Set refreshed state
	resp.Diagnostics.Append(resp.State.Set(ctx, model)...)
	if resp.Diagnostics.HasError() {
		return
	}
	tflog.Info(ctx, "Foo bar read")
}

// Update updates the resource and sets the updated Terraform state on success.
func (r *barResource) Update(ctx context.Context, _ resource.UpdateRequest, resp *resource.UpdateResponse) { // nolint:gocritic // function signature required by Terraform
	// Similar to Create method, calls r.client.UpdateBar (and wait.UpdateBarWaitHandler if needed) instead
}

// Delete deletes the resource and removes the Terraform state on success.
func (r *barResource) Delete(ctx context.Context, req resource.DeleteRequest, resp *resource.DeleteResponse) { // nolint:gocritic // function signature required by Terraform
	var model Model
	diags := req.State.Get(ctx, &model)
	resp.Diagnostics.Append(diags...)
	if resp.Diagnostics.HasError() {
		return
	}

	ctx = core.InitProviderContext(ctx)

	projectId := model.ProjectId.ValueString()
	region := model.Region.ValueString()
	barId := model.BarId.ValueString()
	ctx = tflog.SetField(ctx, "project_id", projectId)
	ctx = tflog.SetField(ctx, "region", region)
	ctx = tflog.SetField(ctx, "bar_id", barId)

	// Delete existing bar
	_, err := r.client.DeleteBar(ctx, projectId, region, barId).Execute()
	if err != nil {
		core.LogAndAddError(ctx, &resp.Diagnostics, "Error deleting bar", fmt.Sprintf("Calling API: %v", err))
	}

	ctx = core.LogResponse(ctx)

	// only in case the bar delete API endpoint is asynchronous: use a wait handler to wait for the delete operation to complete
	_, err = wait.DeleteBarWaitHandler(ctx, r.client, projectId, region, barId).WaitWithContext(ctx)
	if err != nil {
		core.LogAndAddError(ctx, &resp.Diagnostics, "Error deleting bar", fmt.Sprintf("Bar deletion waiting: %v", err))
		return
	}

	tflog.Info(ctx, "Foo bar deleted")
}

// ImportState imports a resource into the Terraform state on success.
// The expected format of the bar resource import identifier is: project_id,bar_id
func (r *barResource) ImportState(ctx context.Context, req resource.ImportStateRequest, resp *resource.ImportStateResponse) {
	idParts := strings.Split(req.ID, core.Separator)
	if len(idParts) != 3 || idParts[0] == "" || idParts[1] == "" || idParts[2] == "" {
		core.LogAndAddError(ctx, &resp.Diagnostics,
			"Error importing bar",
			fmt.Sprintf("Expected import identifier with format [project_id],[region],[bar_id], got %q", req.ID),
		)
		return
	}

	ctx = utils.SetAndLogStateFields(ctx, &resp.Diagnostics, &resp.State, map[string]any{
		"project_id": idParts[0],
		"region":     idParts[1],
		"bar_id":     idParts[2],
	})

	tflog.Info(ctx, "Foo bar state imported")
}

// Maps bar fields to the provider's internal model
func mapFields(barResp *foo.GetBarResponse, model *Model) error {
	if barResp == nil {
		return fmt.Errorf("response input is nil")
	}
	if barResp.Bar == nil {
		return fmt.Errorf("response bar is nil")
	}
	if model == nil {
		return fmt.Errorf("model input is nil")
	}
	bar := barResp.Bar
	model.BarId = types.StringPointerValue(bar.BarId)

	model.Id = utils.BuildInternalTerraformId(
		model.ProjectId.ValueString(),
		model.Region.ValueString(),
		model.BarId.ValueString(),
	)

	model.MyRequiredField = types.StringPointerValue(bar.MyRequiredField)
	model.MyOptionalField = types.StringPointerValue(bar.MyOptionalField)
	model.MyReadOnlyField = types.StringPointerValue(bar.MyOtherField)
	return nil
}

// Build CreateBarPayload from provider's model
func toCreatePayload(model *Model) (*foo.CreateBarPayload, error) {
	if model == nil {
		return nil, fmt.Errorf("nil model")
	}

	myRequiredFieldValue := conversion.StringValueToPointer(model.MyRequiredField)
	myOptionalFieldValue := conversion.StringValueToPointer(model.MyOptionalField)
	return &foo.CreateBarPayload{
		MyRequiredField: myRequiredFieldValue,
		MyOptionalField: myOptionalFieldValue,
	}, nil
}