package provider

import (
	"context"
	"crypto/rand"
	"fmt"
	"strings"

	"github.com/hashicorp/terraform-plugin-framework-jsontypes/jsontypes"
	"github.com/hashicorp/terraform-plugin-framework/resource/schema"
	"github.com/hashicorp/terraform-plugin-framework/types"

	"github.com/maxvojtkov/terraform-provider-dokploy/internal/client"
)

// libSQL is the sixth managed database engine, added in Dokploy v0.30.0.
//
// Its create endpoint is the most awkward in the API: it insists on eleven
// keys being present (several only meaningfully null), it will not generate an
// appName the way the other engines do, and it returns `true` rather than the
// created row. All three are worked around below.

type libsqlModel struct {
	ID            types.String `tfsdk:"id" dokploy:"libsqlId,id"`
	Name          types.String `tfsdk:"name" dokploy:"name"`
	AppName       types.String `tfsdk:"app_name" dokploy:"appName"`
	Description   types.String `tfsdk:"description" dokploy:"description,nullable"`
	EnvironmentID types.String `tfsdk:"environment_id" dokploy:"environmentId"`
	ServerID      types.String `tfsdk:"server_id" dokploy:"serverId,nullable"`

	DatabaseUser     types.String `tfsdk:"database_user" dokploy:"databaseUser"`
	DatabasePassword types.String `tfsdk:"database_password" dokploy:"databasePassword"`
	DockerImage      types.String `tfsdk:"docker_image" dokploy:"dockerImage"`

	SqldNode         types.String `tfsdk:"sqld_node" dokploy:"sqldNode"`
	SqldPrimaryURL   types.String `tfsdk:"sqld_primary_url" dokploy:"sqldPrimaryUrl,nullable"`
	EnableNamespaces types.Bool   `tfsdk:"enable_namespaces" dokploy:"enableNamespaces"`

	Command       types.String `tfsdk:"command" dokploy:"command,nullable"`
	Env           types.String `tfsdk:"env" dokploy:"env,nullable"`
	MemoryReserve types.String `tfsdk:"memory_reservation" dokploy:"memoryReservation,nullable"`
	MemoryLimit   types.String `tfsdk:"memory_limit" dokploy:"memoryLimit,nullable"`
	CPUReserve    types.String `tfsdk:"cpu_reservation" dokploy:"cpuReservation,nullable"`
	CPULimit      types.String `tfsdk:"cpu_limit" dokploy:"cpuLimit,nullable"`
	Replicas      types.Int64  `tfsdk:"replicas" dokploy:"replicas"`

	ExternalPort      types.Int64 `tfsdk:"external_port" dokploy:"externalPort,nullable"`
	ExternalAdminPort types.Int64 `tfsdk:"external_admin_port" dokploy:"externalAdminPort,nullable"`
	ExternalGRPCPort  types.Int64 `tfsdk:"external_grpc_port" dokploy:"externalGRPCPort,nullable"`

	NetworkIDs           types.List `tfsdk:"network_ids" dokploy:"networkIds"`
	DetachDokployNetwork types.Bool `tfsdk:"detach_dokploy_network" dokploy:"detachDokployNetwork"`

	HealthCheckSwarm     jsontypes.Normalized `tfsdk:"health_check_swarm" dokploy:"healthCheckSwarm,nullable"`
	RestartPolicySwarm   jsontypes.Normalized `tfsdk:"restart_policy_swarm" dokploy:"restartPolicySwarm,nullable"`
	PlacementSwarm       jsontypes.Normalized `tfsdk:"placement_swarm" dokploy:"placementSwarm,nullable"`
	UpdateConfigSwarm    jsontypes.Normalized `tfsdk:"update_config_swarm" dokploy:"updateConfigSwarm,nullable"`
	RollbackConfigSwarm  jsontypes.Normalized `tfsdk:"rollback_config_swarm" dokploy:"rollbackConfigSwarm,nullable"`
	ModeSwarm            jsontypes.Normalized `tfsdk:"mode_swarm" dokploy:"modeSwarm,nullable"`
	LabelsSwarm          jsontypes.Normalized `tfsdk:"labels_swarm" dokploy:"labelsSwarm,nullable"`
	NetworkSwarm         jsontypes.Normalized `tfsdk:"network_swarm" dokploy:"networkSwarm,nullable"`
	EndpointSpecSwarm    jsontypes.Normalized `tfsdk:"endpoint_spec_swarm" dokploy:"endpointSpecSwarm,nullable"`
	StopGracePeriodSwarm types.Int64          `tfsdk:"stop_grace_period_swarm" dokploy:"stopGracePeriodSwarm,nullable"`

	ApplicationStatus types.String `tfsdk:"application_status" dokploy:"applicationStatus,ro"`
	CreatedAt         types.String `tfsdk:"created_at" dokploy:"createdAt,ro"`
}

func libsqlResource() ResourceSpec {
	return ResourceSpec{
		Name:              "libsql",
		UpdateAfterCreate: true,
		CreateProc:        "libsql.create",
		ReadProc:          "libsql.one",
		UpdateProc:        "libsql.update",
		DeleteProc:        "libsql.remove",
		NewModel:          func() any { return &libsqlModel{} },

		// `libsql.create` rejects a body that merely omits a key it considers
		// required, even when null is the only sensible value, and it refuses
		// to generate an appName. Fill both in.
		CreateDefaults: func(model any) map[string]any {
			libsql, ok := model.(*libsqlModel)
			if !ok {
				return nil
			}
			defaults := map[string]any{
				"description":    nil,
				"serverId":       nil,
				"sqldPrimaryUrl": nil,
			}
			if libsql.AppName.IsNull() || libsql.AppName.IsUnknown() {
				defaults["appName"] = generateAppName(libsql.Name.ValueString())
			}
			return defaults
		},

		// `libsql.create` returns `true`, so the new ID is found by diffing the
		// environment's libSQL list.
		ListIDs: func(ctx context.Context, api *client.Client, model any) (map[string]struct{}, error) {
			libsql, ok := model.(*libsqlModel)
			if !ok {
				return nil, fmt.Errorf("expected *libsqlModel, got %T", model)
			}
			raw, err := api.Query(ctx, "environment.one", map[string]any{
				"environmentId": libsql.EnvironmentID.ValueString(),
			})
			if err != nil {
				return nil, err
			}
			return collectNestedIDs(raw, "libsql", "libsqlId")
		},

		Schema: schema.Schema{
			MarkdownDescription: databaseNote("libSQL") + "\n\n" +
				"libSQL runs as a `sqld` server. A `primary` node owns the data; a `replica` node follows a " +
				"primary named by `sqld_primary_url`.",
			Attributes: map[string]schema.Attribute{
				"id":   computedID("Unique libSQL identifier."),
				"name": requiredString("Display name of the database."),
				"app_name": optionalComputedReplaceString("Unique Docker service name. Generated from `name` when " +
					"omitted, because Dokploy's libSQL endpoint does not generate one. Changing it forces a new database."),
				"description":    optionalString("Free-form description."),
				"environment_id": requiredReplaceString("Environment this database belongs to."),
				"server_id":      optionalReplaceString("Remote server to deploy on. Omit to use the Dokploy host itself."),

				"database_user":     requiredString("Database user to create."),
				"database_password": sensitiveString("Password for the database user.", true),
				"docker_image": requiredString("libSQL server image to run, for example " +
					"`ghcr.io/tursodatabase/libsql-server:latest`."),

				"sqld_node":        enumStringWithDefault("Role this node plays in a libSQL cluster.", sqldNodes, "primary"),
				"sqld_primary_url": optionalString("URL of the primary node, when `sqld_node` is `replica`."),
				"enable_namespaces": optionalComputedBool("Serve multiple logical databases from one instance " +
					"through libSQL namespaces."),

				"command":            optionalString("Override the container entrypoint command."),
				"env":                optionalString("Environment variables in `KEY=value` format, one per line."),
				"memory_reservation": optionalString("Soft memory reservation, for example `256m`."),
				"memory_limit":       optionalString("Hard memory limit, for example `512m`."),
				"cpu_reservation":    optionalString("Soft CPU reservation, for example `0.5`."),
				"cpu_limit":          optionalString("Hard CPU limit, for example `1`."),
				"replicas":           optionalComputedInt("Number of replicas to run."),

				"external_port":       schema.Int64Attribute{Optional: true, MarkdownDescription: "Host port exposing the HTTP API."},
				"external_admin_port": schema.Int64Attribute{Optional: true, MarkdownDescription: "Host port exposing the admin API."},
				"external_grpc_port":  schema.Int64Attribute{Optional: true, MarkdownDescription: "Host port exposing the gRPC replication endpoint."},

				"network_ids":            optionalComputedStringList("IDs of additional Docker networks to attach."),
				"detach_dokploy_network": optionalComputedBool("Detach the service from the shared `dokploy-network`."),

				"health_check_swarm":      optionalJSON("Docker Swarm health check configuration, as a JSON object."),
				"restart_policy_swarm":    optionalJSON("Docker Swarm restart policy, as a JSON object."),
				"placement_swarm":         optionalJSON("Docker Swarm placement constraints, as a JSON object."),
				"update_config_swarm":     optionalJSON("Docker Swarm rolling update configuration, as a JSON object."),
				"rollback_config_swarm":   optionalJSON("Docker Swarm rollback configuration, as a JSON object."),
				"mode_swarm":              optionalJSON("Docker Swarm service mode, as a JSON object."),
				"labels_swarm":            optionalJSON("Docker Swarm service labels, as a JSON object."),
				"network_swarm":           optionalJSON("Docker Swarm network attachments, as a JSON array."),
				"endpoint_spec_swarm":     optionalJSON("Docker Swarm endpoint specification, as a JSON object."),
				"stop_grace_period_swarm": schema.Int64Attribute{Optional: true, MarkdownDescription: "Grace period in nanoseconds before a container is killed."},

				"application_status": computedString("Current status reported by Dokploy: `idle`, `running`, `done` or `error`."),
				"created_at":         computedString("RFC 3339 timestamp of when the database was created."),
			},
		},
	}
}

// generateAppName mirrors how Dokploy names a service: a slug of the display
// name plus a short random suffix, so two databases called "cache" in
// different projects do not collide on the Docker host.
func generateAppName(name string) string {
	var slug strings.Builder
	lastDash := true
	for _, r := range strings.ToLower(name) {
		switch {
		case (r >= 'a' && r <= 'z') || (r >= '0' && r <= '9'):
			slug.WriteRune(r)
			lastDash = false
		case !lastDash:
			slug.WriteByte('-')
			lastDash = true
		}
	}
	base := strings.Trim(slug.String(), "-")
	if base == "" {
		base = "libsql"
	}
	return base + "-" + randomSuffix(6)
}

const suffixAlphabet = "abcdefghijklmnopqrstuvwxyz0123456789"

func randomSuffix(n int) string {
	buf := make([]byte, n)
	if _, err := rand.Read(buf); err != nil {
		// crypto/rand does not fail in practice; a fixed suffix still yields a
		// usable name and Dokploy rejects a genuine collision.
		return strings.Repeat("0", n)
	}
	for i, b := range buf {
		buf[i] = suffixAlphabet[int(b)%len(suffixAlphabet)]
	}
	return string(buf)
}