// SPDX-License-Identifier: BUSL-1.1
// Copyright (c) 2025 StellaOps
// Sprint: SPRINT_20260122_039_Scanner_runtime_linkage_verification
// Task: RLV-009 - Platform API: Function Map Endpoints

using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Routing;
using StellaOps.Auth.ServerIntegration.Tenancy;
using StellaOps.Platform.WebService.Constants;
using StellaOps.Platform.WebService.Contracts;
using StellaOps.Platform.WebService.Services;

namespace StellaOps.Platform.WebService.Endpoints;

/// <summary>
/// Function map management API endpoints.
/// </summary>
public static class FunctionMapEndpoints
{
    /// <summary>
    /// Maps function-map-related endpoints.
    /// </summary>
    public static IEndpointRouteBuilder MapFunctionMapEndpoints(this IEndpointRouteBuilder app)
    {
        var maps = app.MapGroup("/api/v1/function-maps")
            .WithTags("Function Maps")
            .RequireAuthorization(PlatformPolicies.FunctionMapRead)
            .RequireTenant();

        MapCrudEndpoints(maps);
        MapVerifyEndpoints(maps);

        return app;
    }

    private static void MapCrudEndpoints(IEndpointRouteBuilder maps)
    {
        // POST /api/v1/function-maps - Create function map
        maps.MapPost("/", async Task<IResult> (
            HttpContext context,
            PlatformRequestContextResolver resolver,
            IFunctionMapService service,
            [FromBody] CreateFunctionMapRequest request,
            CancellationToken cancellationToken) =>
        {
            if (!TryResolveContext(context, resolver, out var requestContext, out var failure))
            {
                return failure!;
            }

            var result = await service.CreateAsync(
                requestContext!,
                request,
                cancellationToken).ConfigureAwait(false);

            return Results.Created(
                $"/api/v1/function-maps/{result.Value.Id}",
                new PlatformItemResponse<FunctionMapDetail>(
                    requestContext!.TenantId,
                    requestContext.ActorId,
                    result.DataAsOf,
                    result.Cached,
                    result.CacheTtlSeconds,
                    result.Value));
        })
        .WithName("CreateFunctionMap")
        .WithSummary("Create function map")
        .WithDescription("Creates a new function map from an SBOM reference and hot function patterns.")
        .RequireAuthorization(PlatformPolicies.FunctionMapWrite);

        // GET /api/v1/function-maps - List function maps
        maps.MapGet("/", async Task<IResult> (
            HttpContext context,
            PlatformRequestContextResolver resolver,
            IFunctionMapService service,
            [FromQuery] int? limit,
            [FromQuery] int? offset,
            CancellationToken cancellationToken) =>
        {
            if (!TryResolveContext(context, resolver, out var requestContext, out var failure))
            {
                return failure!;
            }

            var result = await service.ListAsync(
                requestContext!,
                limit ?? 100,
                offset ?? 0,
                cancellationToken).ConfigureAwait(false);

            return Results.Ok(new PlatformListResponse<FunctionMapSummary>(
                requestContext!.TenantId,
                requestContext.ActorId,
                result.DataAsOf,
                result.Cached,
                result.CacheTtlSeconds,
                result.Value,
                result.Value.Count,
                limit ?? 100,
                offset ?? 0));
        })
        .WithName("ListFunctionMaps")
        .WithSummary("List function maps")
        .WithDescription("Lists all function maps for the current tenant.")
        .RequireAuthorization(PlatformPolicies.FunctionMapRead);

        // GET /api/v1/function-maps/{id} - Get function map by ID
        maps.MapGet("/{id}", async Task<IResult> (
            HttpContext context,
            PlatformRequestContextResolver resolver,
            IFunctionMapService service,
            string id,
            CancellationToken cancellationToken) =>
        {
            if (!TryResolveContext(context, resolver, out var requestContext, out var failure))
            {
                return failure!;
            }

            var result = await service.GetByIdAsync(
                requestContext!,
                id,
                cancellationToken).ConfigureAwait(false);

            if (result.Value is null)
            {
                return Results.NotFound(new { error = "Function map not found", id });
            }

            return Results.Ok(new PlatformItemResponse<FunctionMapDetail>(
                requestContext!.TenantId,
                requestContext.ActorId,
                result.DataAsOf,
                result.Cached,
                result.CacheTtlSeconds,
                result.Value));
        })
        .WithName("GetFunctionMap")
        .WithSummary("Get function map")
        .WithDescription("Retrieves a function map by its unique identifier.")
        .RequireAuthorization(PlatformPolicies.FunctionMapRead);

        // DELETE /api/v1/function-maps/{id} - Delete function map
        maps.MapDelete("/{id}", async Task<IResult> (
            HttpContext context,
            PlatformRequestContextResolver resolver,
            IFunctionMapService service,
            string id,
            CancellationToken cancellationToken) =>
        {
            if (!TryResolveContext(context, resolver, out var requestContext, out var failure))
            {
                return failure!;
            }

            var result = await service.DeleteAsync(
                requestContext!,
                id,
                cancellationToken).ConfigureAwait(false);

            if (!result.Value)
            {
                return Results.NotFound(new { error = "Function map not found", id });
            }

            return Results.NoContent();
        })
        .WithName("DeleteFunctionMap")
        .WithSummary("Delete function map")
        .WithDescription("Deletes a function map by its unique identifier.")
        .RequireAuthorization(PlatformPolicies.FunctionMapWrite);
    }

    private static void MapVerifyEndpoints(IEndpointRouteBuilder maps)
    {
        // POST /api/v1/function-maps/{id}/verify - Verify observations against map
        maps.MapPost("/{id}/verify", async Task<IResult> (
            HttpContext context,
            PlatformRequestContextResolver resolver,
            IFunctionMapService service,
            string id,
            [FromBody] VerifyFunctionMapRequest request,
            CancellationToken cancellationToken) =>
        {
            if (!TryResolveContext(context, resolver, out var requestContext, out var failure))
            {
                return failure!;
            }

            var result = await service.VerifyAsync(
                requestContext!,
                id,
                request,
                cancellationToken).ConfigureAwait(false);

            return Results.Ok(new PlatformItemResponse<FunctionMapVerifyResponse>(
                requestContext!.TenantId,
                requestContext.ActorId,
                result.DataAsOf,
                result.Cached,
                result.CacheTtlSeconds,
                result.Value));
        })
        .WithName("VerifyFunctionMap")
        .WithSummary("Verify function map")
        .WithDescription("Verifies runtime observations against a declared function map.")
        .RequireAuthorization(PlatformPolicies.FunctionMapVerify);

        // GET /api/v1/function-maps/{id}/coverage - Get coverage statistics
        maps.MapGet("/{id}/coverage", async Task<IResult> (
            HttpContext context,
            PlatformRequestContextResolver resolver,
            IFunctionMapService service,
            string id,
            CancellationToken cancellationToken) =>
        {
            if (!TryResolveContext(context, resolver, out var requestContext, out var failure))
            {
                return failure!;
            }

            var result = await service.GetCoverageAsync(
                requestContext!,
                id,
                cancellationToken).ConfigureAwait(false);

            return Results.Ok(new PlatformItemResponse<FunctionMapCoverageResponse>(
                requestContext!.TenantId,
                requestContext.ActorId,
                result.DataAsOf,
                result.Cached,
                result.CacheTtlSeconds,
                result.Value));
        })
        .WithName("GetFunctionMapCoverage")
        .WithSummary("Get function map coverage")
        .WithDescription("Returns current coverage statistics for a function map.")
        .RequireAuthorization(PlatformPolicies.FunctionMapRead);
    }

    private static bool TryResolveContext(
        HttpContext context,
        PlatformRequestContextResolver resolver,
        out PlatformRequestContext? requestContext,
        out IResult? failure)
    {
        if (resolver.TryResolve(context, out requestContext, out var error))
        {
            failure = null;
            return true;
        }

        failure = Results.BadRequest(new { error = error ?? "tenant_missing" });
        return false;
    }
}