import {
    createTenantContext,
    NullTenantContext,
    type Tenant,
    type TenantContext,
    type TenantResolver,
} from "@suaveplan/api-tenant";
import type { Context } from "hono";
import {
    TENANT_PLUGIN_CODES,
    TenantPluginError,
} from "../error-codes/error-codes.js";
import { getTenantPluginInstruments } from "../otel/instruments.js";
import type {
    CreateTenantInput,
    ListTenantsQuery,
    TenantStore,
    UpdateTenantInput,
} from "../store/store.js";

/**
 * Inputs required to build the canonical `TenantService` implementation.
 * The resolver is always present (composed at `onInit`); the store is
 * optional — when absent, CRUD methods throw STORE_NOT_CONFIGURED.
 */
export interface CreateTenantServiceOptions {
    readonly resolver: TenantResolver;
    readonly store?: TenantStore;
}

/**
 * Service slot registered by `createTenantPlugin` in the host
 * `ServiceRegistry`. Downstream plugins and route handlers call
 * `ctx.getService("tenantService")` for the helper bag of tenant ops.
 */
export interface TenantService {
    /** Look up the tenant for the current request by re-running the resolver chain. */
    resolveFrom(c: Context): Promise<TenantContext>;
    /** Same as {@link resolveFrom} but throws when no tenant is resolved. */
    requireFrom(c: Context): TenantContext;
    /** Read the tenant set on the Hono context by the middleware (or NullTenantContext). */
    current(c: Context): TenantContext;
    /** Direct store lookup. Returns `null` when store is absent. */
    getById(id: string): Promise<Tenant | null>;
    /** Store-backed listing. Throws STORE_NOT_CONFIGURED when no store. */
    listAll(query?: ListTenantsQuery): Promise<readonly Tenant[]>;
    /** Store-backed create. Throws STORE_NOT_CONFIGURED when no store. */
    createTenant(input: CreateTenantInput): Promise<Tenant>;
    /** Store-backed update. Throws STORE_NOT_CONFIGURED when no store. */
    updateTenant(id: string, patch: UpdateTenantInput): Promise<Tenant>;
    /** Store-backed soft-delete. Throws STORE_NOT_CONFIGURED when no store. */
    deleteTenant(id: string): Promise<void>;
    /** The composed resolver — exposed for diagnostics + advanced use. */
    getResolver(): TenantResolver;
}

function requireStore(store: TenantStore | undefined, op: string): TenantStore {
    if (store === undefined) {
        throw new TenantPluginError(
            TENANT_PLUGIN_CODES.STORE_NOT_CONFIGURED,
            `tenantService.${op} requires a TenantStore but none was configured`,
            { context: { op, statusCode: 500 } }
        );
    }
    return store;
}

/**
 * Construct the canonical `TenantService` backed by the supplied
 * resolver chain and optional store. Every CRUD method increments
 * `tenant_plugin.management_ops_total` with the resolved outcome.
 */
export function createTenantService(
    options: CreateTenantServiceOptions
): TenantService {
    const { resolver, store } = options;

    return {
        async resolveFrom(c) {
            const tenant = await resolver.resolve(c);
            return tenant ? createTenantContext(tenant) : NullTenantContext;
        },
        requireFrom(c) {
            const tenant = c.get("tenant");
            if (tenant === undefined) {
                throw new TenantPluginError(
                    TENANT_PLUGIN_CODES.TENANT_NOT_FOUND,
                    "No tenant resolved for the current request",
                    { context: { statusCode: 404 } }
                );
            }
            return createTenantContext(tenant);
        },
        current(c) {
            const tenant = c.get("tenant");
            return tenant ? createTenantContext(tenant) : NullTenantContext;
        },
        async getById(id) {
            const instruments = getTenantPluginInstruments();
            if (store === undefined) {
                instruments.managementOpsTotal.add(1, {
                    op: "read",
                    outcome: "failure",
                });
                throw new TenantPluginError(
                    TENANT_PLUGIN_CODES.STORE_NOT_CONFIGURED,
                    "tenantService.getById requires a TenantStore but none was configured",
                    { context: { op: "read", statusCode: 500 } }
                );
            }
            try {
                const result = await store.getById(id);
                instruments.managementOpsTotal.add(1, {
                    op: "read",
                    outcome: "success",
                });
                return result;
            } catch (err) {
                instruments.managementOpsTotal.add(1, {
                    op: "read",
                    outcome: "failure",
                });
                throw err;
            }
        },
        async listAll(query) {
            const instruments = getTenantPluginInstruments();
            const s = requireStore(store, "listAll");
            try {
                const rows = await s.listAll(query);
                instruments.managementOpsTotal.add(1, {
                    op: "list",
                    outcome: "success",
                });
                return rows;
            } catch (err) {
                instruments.managementOpsTotal.add(1, {
                    op: "list",
                    outcome: "failure",
                });
                throw err;
            }
        },
        async createTenant(input) {
            const instruments = getTenantPluginInstruments();
            const s = requireStore(store, "createTenant");
            try {
                const tenant = await s.create(input);
                instruments.managementOpsTotal.add(1, {
                    op: "create",
                    outcome: "success",
                });
                return tenant;
            } catch (err) {
                instruments.managementOpsTotal.add(1, {
                    op: "create",
                    outcome: "failure",
                });
                throw err;
            }
        },
        async updateTenant(id, patch) {
            const instruments = getTenantPluginInstruments();
            const s = requireStore(store, "updateTenant");
            try {
                const tenant = await s.update(id, patch);
                instruments.managementOpsTotal.add(1, {
                    op: "update",
                    outcome: "success",
                });
                return tenant;
            } catch (err) {
                instruments.managementOpsTotal.add(1, {
                    op: "update",
                    outcome: "failure",
                });
                throw err;
            }
        },
        async deleteTenant(id) {
            const instruments = getTenantPluginInstruments();
            const s = requireStore(store, "deleteTenant");
            try {
                await s.delete(id);
                instruments.managementOpsTotal.add(1, {
                    op: "delete",
                    outcome: "success",
                });
            } catch (err) {
                instruments.managementOpsTotal.add(1, {
                    op: "delete",
                    outcome: "failure",
                });
                throw err;
            }
        },
        getResolver() {
            return resolver;
        },
    };
}