package argus

import (
	"context"
	"fmt"
	"net/http"

	"github.com/hashicorp/terraform-plugin-framework-validators/stringvalidator"
	"github.com/hashicorp/terraform-plugin-framework/datasource"
	"github.com/hashicorp/terraform-plugin-framework/datasource/schema"
	"github.com/hashicorp/terraform-plugin-framework/schema/validator"
	"github.com/hashicorp/terraform-plugin-framework/types"
	"github.com/hashicorp/terraform-plugin-log/tflog"
	"github.com/stackitcloud/stackit-sdk-go/core/config"
	"github.com/stackitcloud/stackit-sdk-go/core/oapierror"
	"github.com/stackitcloud/stackit-sdk-go/services/argus"
	"github.com/stackitcloud/stackit-sdk-go/services/argus/wait"
	"github.com/stackitcloud/terraform-provider-stackit/stackit/internal/core"
	"github.com/stackitcloud/terraform-provider-stackit/stackit/internal/validate"
)

// Ensure the implementation satisfies the expected interfaces.
var (
	_ datasource.DataSource = &instanceDataSource{}
)

// NewInstanceDataSource is a helper function to simplify the provider implementation.
func NewInstanceDataSource() datasource.DataSource {
	return &instanceDataSource{}
}

// instanceDataSource is the data source implementation.
type instanceDataSource struct {
	client *argus.APIClient
}

// Metadata returns the data source type name.
func (d *instanceDataSource) Metadata(_ context.Context, req datasource.MetadataRequest, resp *datasource.MetadataResponse) {
	resp.TypeName = req.ProviderTypeName + "_argus_instance"
}

func (d *instanceDataSource) Configure(ctx context.Context, req datasource.ConfigureRequest, resp *datasource.ConfigureResponse) {
	// Prevent panic if the provider has not been configured.
	if req.ProviderData == nil {
		return
	}

	var apiClient *argus.APIClient
	var err error

	providerData, ok := req.ProviderData.(core.ProviderData)
	if !ok {
		core.LogAndAddError(ctx, &resp.Diagnostics, "Error configuring API client", fmt.Sprintf("Expected configure type stackit.ProviderData, got %T", req.ProviderData))
		return
	}

	if providerData.ArgusCustomEndpoint != "" {
		apiClient, err = argus.NewAPIClient(
			config.WithCustomAuth(providerData.RoundTripper),
			config.WithEndpoint(providerData.ArgusCustomEndpoint),
		)
	} else {
		apiClient, err = argus.NewAPIClient(
			config.WithCustomAuth(providerData.RoundTripper),
			config.WithRegion(providerData.Region),
		)
	}
	if err != nil {
		core.LogAndAddError(ctx, &resp.Diagnostics, "Error configuring API client", fmt.Sprintf("Configuring client: %v. This is an error related to the provider configuration, not to the data source configuration", err))
		return
	}
	d.client = apiClient
	tflog.Info(ctx, "Argus instance client configured")
}

// Schema defines the schema for the data source.
func (d *instanceDataSource) Schema(_ context.Context, _ datasource.SchemaRequest, resp *datasource.SchemaResponse) {
	resp.Schema = schema.Schema{
		Description: "Argus instance data source schema. Must have a `region` specified in the provider configuration.",
		Attributes: map[string]schema.Attribute{
			"id": schema.StringAttribute{
				Description: "Terraform's internal data source. ID. It is structured as \"`project_id`,`instance_id`\".",
				Computed:    true,
			},
			"project_id": schema.StringAttribute{
				Description: "STACKIT project ID to which the instance is associated.",
				Required:    true,
				Validators: []validator.String{
					validate.UUID(),
					validate.NoSeparator(),
				},
			},
			"instance_id": schema.StringAttribute{
				Description: "The Argus instance ID.",
				Required:    true,
				Validators: []validator.String{
					validate.UUID(),
					validate.NoSeparator(),
				},
			},
			"name": schema.StringAttribute{
				Description: "The name of the Argus instance.",
				Computed:    true,
				Validators: []validator.String{
					stringvalidator.LengthAtLeast(1),
					stringvalidator.LengthAtMost(300),
				},
			},
			"plan_name": schema.StringAttribute{
				Description: "Specifies the Argus plan. E.g. `Monitoring-Medium-EU01`.",
				Computed:    true,
				Validators: []validator.String{
					stringvalidator.LengthAtLeast(1),
					stringvalidator.LengthAtMost(200),
				},
			},
			"plan_id": schema.StringAttribute{
				Description: "The Argus plan ID.",
				Computed:    true,
				Validators: []validator.String{
					validate.UUID(),
				},
			},
			"parameters": schema.MapAttribute{
				Description: "Additional parameters.",
				Computed:    true,
				ElementType: types.StringType,
			},
			"dashboard_url": schema.StringAttribute{
				Description: "Specifies Argus instance dashboard URL.",
				Computed:    true,
			},
			"is_updatable": schema.BoolAttribute{
				Description: "Specifies if the instance can be updated.",
				Computed:    true,
			},
			"grafana_public_read_access": schema.BoolAttribute{
				Description: "If true, anyone can access Grafana dashboards without logging in.",
				Computed:    true,
			},
			"grafana_url": schema.StringAttribute{
				Description: "Specifies Grafana URL.",
				Computed:    true,
			},
			"grafana_initial_admin_user": schema.StringAttribute{
				Description: "Specifies an initial Grafana admin username.",
				Computed:    true,
			},
			"grafana_initial_admin_password": schema.StringAttribute{
				Description: "Specifies an initial Grafana admin password.",
				Computed:    true,
				Sensitive:   true,
			},
			"metrics_retention_days": schema.Int64Attribute{
				Description: "Specifies for how many days the raw metrics are kept.",
				Computed:    true,
			},
			"metrics_retention_days_5m_downsampling": schema.Int64Attribute{
				Description: "Specifies for how many days the 5m downsampled metrics are kept. must be less than the value of the general retention. Default is set to `0` (disabled).",
				Computed:    true,
			},
			"metrics_retention_days_1h_downsampling": schema.Int64Attribute{
				Description: "Specifies for how many days the 1h downsampled metrics are kept. must be less than the value of the 5m downsampling retention. Default is set to `0` (disabled).",
				Computed:    true,
			},
			"metrics_url": schema.StringAttribute{
				Description: "Specifies metrics URL.",
				Computed:    true,
			},
			"metrics_push_url": schema.StringAttribute{
				Description: "Specifies URL for pushing metrics.",
				Computed:    true,
			},
			"targets_url": schema.StringAttribute{
				Description: "Specifies Targets URL.",
				Computed:    true,
			},
			"alerting_url": schema.StringAttribute{
				Description: "Specifies Alerting URL.",
				Computed:    true,
			},
			"logs_url": schema.StringAttribute{
				Description: "Specifies Logs URL.",
				Computed:    true,
			},
			"logs_push_url": schema.StringAttribute{
				Description: "Specifies URL for pushing logs.",
				Computed:    true,
			},
			"jaeger_traces_url": schema.StringAttribute{
				Computed: true,
			},
			"jaeger_ui_url": schema.StringAttribute{
				Computed: true,
			},
			"otlp_traces_url": schema.StringAttribute{
				Computed: true,
			},
			"zipkin_spans_url": schema.StringAttribute{
				Computed: true,
			},
			"acl": schema.SetAttribute{
				Description: "The access control list for this instance. Each entry is an IP address range that is permitted to access, in CIDR notation.",
				ElementType: types.StringType,
				Computed:    true,
			},
		},
	}
}

// Read refreshes the Terraform state with the latest data.
func (d *instanceDataSource) Read(ctx context.Context, req datasource.ReadRequest, resp *datasource.ReadResponse) { // nolint:gocritic // function signature required by Terraform
	var model Model
	diags := req.Config.Get(ctx, &model)
	resp.Diagnostics.Append(diags...)
	if resp.Diagnostics.HasError() {
		return
	}
	projectId := model.ProjectId.ValueString()
	instanceId := model.InstanceId.ValueString()
	instanceResp, err := d.client.GetInstance(ctx, instanceId, projectId).Execute()
	if err != nil {
		oapiErr, ok := err.(*oapierror.GenericOpenAPIError) //nolint:errorlint //complaining that error.As should be used to catch wrapped errors, but this error should not be wrapped
		if ok && oapiErr.StatusCode == http.StatusNotFound {
			resp.State.RemoveResource(ctx)
		}
		core.LogAndAddError(ctx, &resp.Diagnostics, "Error reading instance", fmt.Sprintf("Calling API: %v", err))
		return
	}
	if instanceResp != nil && instanceResp.Status != nil && *instanceResp.Status == wait.DeleteSuccess {
		resp.State.RemoveResource(ctx)
		core.LogAndAddError(ctx, &resp.Diagnostics, "Error reading instance", "Instance was deleted successfully")
		return
	}

	aclListResp, err := d.client.ListACL(ctx, instanceId, projectId).Execute()
	if err != nil {
		core.LogAndAddError(ctx, &resp.Diagnostics, "Error reading instance", fmt.Sprintf("Calling API to list ACL data: %v", err))
		return
	}

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

	diags = resp.State.Set(ctx, model)
	resp.Diagnostics.Append(diags...)
	if resp.Diagnostics.HasError() {
		return
	}
	tflog.Info(ctx, "Argus instance read")
}