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

package provider

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

	"terraform-provider-virtfusion/internal/client"

	"github.com/hashicorp/terraform-plugin-framework/attr"
	"github.com/hashicorp/terraform-plugin-framework/datasource"
	"github.com/hashicorp/terraform-plugin-framework/datasource/schema"
	"github.com/hashicorp/terraform-plugin-framework/types"
)

var _ datasource.DataSource = &ServersDataSource{}
var _ datasource.DataSourceWithConfigure = &ServersDataSource{}

// NewServersDataSource returns a new data source for listing all servers.
func NewServersDataSource() datasource.DataSource {
	return &ServersDataSource{}
}

// ServersDataSource defines the data source implementation.
type ServersDataSource struct {
	client *client.Client
}

// ServersDataSourceModel describes the data source data model.
type ServersDataSourceModel struct {
	Results types.Int64 `tfsdk:"results"`
	Servers types.List  `tfsdk:"servers"`
}

func (d *ServersDataSource) Metadata(_ context.Context, req datasource.MetadataRequest, resp *datasource.MetadataResponse) {
	resp.TypeName = req.ProviderTypeName + "_servers"
}

func (d *ServersDataSource) Schema(_ context.Context, _ datasource.SchemaRequest, resp *datasource.SchemaResponse) {
	resp.Schema = schema.Schema{
		MarkdownDescription: "Use this data source to list all VirtFusion servers.",
		Attributes: map[string]schema.Attribute{
			"results": resultsSchemaAttribute(),
			"servers": schema.ListNestedAttribute{
				MarkdownDescription: "The list of servers.",
				Computed:            true,
				NestedObject: schema.NestedAttributeObject{
					Attributes: serverDataSourceSchemaAttributes(),
				},
			},
		},
	}
}

func (d *ServersDataSource) Configure(_ context.Context, req datasource.ConfigureRequest, resp *datasource.ConfigureResponse) {
	if req.ProviderData == nil {
		return
	}

	c, ok := req.ProviderData.(*client.Client)
	if !ok {
		resp.Diagnostics.AddError(
			"Unexpected Data Source Configure Type",
			fmt.Sprintf("Expected *client.Client, got: %T. Please report this issue to the provider developers.", req.ProviderData),
		)
		return
	}

	d.client = c
}

func (d *ServersDataSource) Read(ctx context.Context, req datasource.ReadRequest, resp *datasource.ReadResponse) {
	var data ServersDataSourceModel
	resp.Diagnostics.Append(req.Config.Get(ctx, &data)...)
	if resp.Diagnostics.HasError() {
		return
	}

	result, err := d.client.GetAllPages(ctx, fmt.Sprintf("/servers?%s", resultsQueryParam(data.Results)))
	if err != nil {
		resp.Diagnostics.AddError("Error Reading Servers", err.Error())
		return
	}

	var listResp client.ServerListResponse
	if err := json.Unmarshal(result, &listResp); err != nil {
		resp.Diagnostics.AddError("Error Parsing Servers Response", err.Error())
		return
	}

	serverObjects := make([]attr.Value, len(listResp.Data))
	for i, s := range listResp.Data {
		obj, diags := types.ObjectValue(
			serverDataSourceAttrTypes(),
			serverDataToAttrValues(s),
		)
		resp.Diagnostics.Append(diags...)
		if resp.Diagnostics.HasError() {
			return
		}
		serverObjects[i] = obj
	}

	serversList, diags := types.ListValue(types.ObjectType{AttrTypes: serverDataSourceAttrTypes()}, serverObjects)
	resp.Diagnostics.Append(diags...)
	if resp.Diagnostics.HasError() {
		return
	}

	data.Servers = serversList

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

// serverDataSourceSchemaAttributes returns the schema attributes for a server object
// used in list data sources.
func serverDataSourceSchemaAttributes() map[string]schema.Attribute {
	return map[string]schema.Attribute{
		"id": schema.Int64Attribute{
			MarkdownDescription: "The server ID.",
			Computed:            true,
		},
		"uuid": schema.StringAttribute{
			MarkdownDescription: "The server UUID.",
			Computed:            true,
		},
		"name": schema.StringAttribute{
			MarkdownDescription: "The server display name.",
			Computed:            true,
		},
		"hostname": schema.StringAttribute{
			MarkdownDescription: "The server hostname.",
			Computed:            true,
		},
		"owner_id": schema.Int64Attribute{
			MarkdownDescription: "The owner (user) ID who owns the server.",
			Computed:            true,
		},
		"hypervisor_id": schema.Int64Attribute{
			MarkdownDescription: "The hypervisor ID where the server is hosted.",
			Computed:            true,
		},
		"suspended": schema.BoolAttribute{
			MarkdownDescription: "Whether the server is suspended.",
			Computed:            true,
		},
	}
}

// serverDataSourceAttrTypes returns the attribute types for a server object.
func serverDataSourceAttrTypes() map[string]attr.Type {
	return map[string]attr.Type{
		"id":            types.Int64Type,
		"uuid":          types.StringType,
		"name":          types.StringType,
		"hostname":      types.StringType,
		"owner_id":      types.Int64Type,
		"hypervisor_id": types.Int64Type,
		"suspended":     types.BoolType,
	}
}

// serverDataToAttrValues converts a client.ServerData to a map of attribute values.
func serverDataToAttrValues(s client.ServerData) map[string]attr.Value {
	return map[string]attr.Value{
		"id":            types.Int64Value(s.ID),
		"uuid":          types.StringValue(s.UUID),
		"name":          types.StringValue(s.Name),
		"hostname":      types.StringValue(s.Hostname),
		"owner_id":      types.Int64Value(s.OwnerID),
		"hypervisor_id": types.Int64Value(s.HypervisorID),
		"suspended":     types.BoolValue(s.Suspended),
	}
}