/**
 * @node sdcpp-generate
 * @name SD.cpp Generate
 * @category sdcpp
 * @version 1.0.0
 * @description Queue an image or video generation job on an sdcpp-restapi server and return its job id
 * @icon image-plus
 */

const configSchema = {
    type: 'object',
    properties: {
        serverUrl: {
            type: 'string',
            title: 'Server URL',
            description: 'Base address of the sdcpp-restapi server, such as http://localhost:8077. No trailing slash needed',
            default: 'http://localhost:8077'
        },
        credentialId: {
            type: 'string',
            title: 'Credential',
            description: 'A basic credential holding the sdcpp-restapi username and password. Every endpoint except health requires one',
            dynamicOptions: {
                source: 'credentials',
                filter: { type: ['basic'] }
            }
        },
        operation: {
            type: 'string',
            title: 'Operation',
            enum: ['txt2img', 'img2img', 'txt2vid', 'upscale'],
            default: 'txt2img',
            description: 'txt2img generates from a prompt alone, img2img and txt2vid start from an image, upscale enlarges one using the separately loaded upscaler'
        },
        prompt: {
            type: 'string',
            title: 'Prompt',
            description: 'What to generate. Supports {{variable}} interpolation and <lora:name:weight> syntax. Also supports {a|b|c} dynamic prompts, which the server expands into one queue item per variation',
            format: 'textarea'
        },
        negativePrompt: {
            type: 'string',
            title: 'Negative Prompt',
            description: 'Concepts to exclude. Has no effect on LCM and one-step SDXS models',
            format: 'textarea'
        },
        width: {
            type: 'number',
            title: 'Width',
            description: 'Leave empty to use the loaded architecture default, such as 1024 for SDXL and Flux'
        },
        height: {
            type: 'number',
            title: 'Height',
            description: 'Leave empty to use the loaded architecture default'
        },
        steps: {
            type: 'number',
            title: 'Steps',
            description: 'Sampling steps. Leave empty to use the architecture default, which is 4 for Flux Schnell and LCM and 20 for most others'
        },
        cfgScale: {
            type: 'number',
            title: 'CFG Scale',
            description: 'Guidance strength. Leave empty to use the architecture default. Distilled models such as Flux Schnell, LCM and Z-Image want 1.0'
        },
        sampler: {
            type: 'string',
            title: 'Sampler',
            enum: ['', 'euler', 'euler_a', 'heun', 'dpm2', 'dpm++2s_a', 'dpm++2m', 'dpm++2mv2',
                'ipndm', 'ipndm_v', 'lcm', 'ddim_trailing', 'tcd', 'res_multistep', 'res_2s',
                'er_sde', 'euler_cfg_pp', 'euler_a_cfg_pp', 'euler_ge'],
            default: '',
            description: 'Leave empty to use the architecture default'
        },
        scheduler: {
            type: 'string',
            title: 'Scheduler',
            enum: ['', 'discrete', 'karras', 'exponential', 'ays', 'gits', 'sgm_uniform',
                'simple', 'smoothstep', 'kl_optimal', 'lcm', 'bong_tangent', 'ltx2'],
            default: '',
            description: 'Leave empty to use the architecture default'
        },
        seed: {
            type: 'number',
            title: 'Seed',
            description: 'Use -1 for a random seed. Any other value reproduces the same image. Leave empty to let the server decide'
        },
        batchCount: {
            type: 'number',
            title: 'Batch Count',
            description: 'How many images to generate in this one job, all sharing the prompt'
        },
        clipSkip: {
            type: 'number',
            title: 'CLIP Skip',
            description: 'Skip the last N CLIP layers. Negative means the model default'
        },
        title: {
            type: 'string',
            title: 'Job Title',
            description: 'Optional label stored with the job, useful for finding it again in the queue'
        },
        initImageBase64: {
            type: 'string',
            title: 'Init Image (base64)',
            description: 'Starting image for img2img and txt2vid, and the image to enlarge for upscale. Base64 without a data: prefix. Usually {{$json.file.data}} from a previous node'
        },
        maskImageBase64: {
            type: 'string',
            title: 'Mask Image (base64)',
            description: 'Inpainting mask for img2img. White marks the area to regenerate'
        },
        strength: {
            type: 'number',
            title: 'Strength',
            description: 'How far img2img and txt2vid may move from the init image, from 0 to 1. Higher changes more'
        },
        upscaleFactor: {
            type: 'number',
            title: 'Upscale Factor',
            description: 'For the upscale operation. The upscaler model must already be loaded'
        },
        videoFrames: {
            type: 'number',
            title: 'Video Frames',
            description: 'For txt2vid, how many frames to render'
        },
        fps: {
            type: 'number',
            title: 'FPS',
            description: 'For txt2vid, frames per second of the output video'
        },
        extraOptions: {
            type: 'object',
            title: 'Extra Options',
            description: 'Any other generation field passed straight through to the server, such as slg_scale, cache_mode, ref_images or vae_tiling. Names must match the API exactly. See /options/generation on the server for the full list with descriptions'
        },
        timeout: {
            type: 'number',
            title: 'Timeout (ms)',
            description: 'Applies to queueing the job, not to the render itself. The call returns as soon as the job is accepted',
            default: 30000
        }
    },
    required: ['credentialId']
};

const inputSchema = {
    type: 'object',
    properties: {
        data: { type: 'any' }
    }
};

const outputSchema = {
    type: 'object',
    properties: {
        jobId: { type: 'string', description: 'Id of the queued job, to pass to SD.cpp Job Status or Wait' },
        status: { type: 'string', description: 'Queue status at the moment of accepting, normally pending' },
        position: { type: 'number', description: 'Place in the queue when it was accepted' },
        operation: { type: 'string', description: 'Which generation endpoint was called' },
        request: { type: 'object', description: 'The body actually sent, useful for debugging which defaults were left to the server' }
    }
};

function normalizeServer(url) {
    const value = String(url || '').trim();
    if (!value) {
        throw new Error('SD.cpp: a server URL is required, such as http://localhost:8077');
    }
    return value.replace(/\/+$/, '');
}

function readCredential(credentialId) {
    const auth = smartbotic.credentials.get(credentialId);
    if (!auth || auth.success !== true) {
        throw new Error('SD.cpp: could not read the credential: ' +
            ((auth && auth.error) || 'unknown error'));
    }

    const value = auth.headerValue || '';
    if (value.indexOf('Basic ') !== 0) {
        throw new Error('SD.cpp: the credential must be a basic one, holding the sdcpp-restapi ' +
            'username and password');
    }

    const decoded = smartbotic.utils.base64Decode(value.substring(6));
    const separator = decoded.indexOf(':');
    if (separator < 1) {
        throw new Error('SD.cpp: the credential is malformed, expected a username and a password');
    }

    return {
        username: decoded.substring(0, separator),
        password: decoded.substring(separator + 1)
    };
}

function call(options) {
    const response = smartbotic.http.request(options);

    let body = response.data;
    if (typeof body === 'string' && body.length > 0) {
        try {
            body = JSON.parse(body);
        } catch (e) {
            const snippet = body.substring(0, 200).replace(/\s+/g, ' ');
            throw new Error('SD.cpp: ' + options.what + ' returned HTTP ' + response.status +
                ' with a body that is not JSON: ' + snippet);
        }
    }

    if (response.status < 200 || response.status >= 300) {
        const detail = (body && (body.message || body.error)) || ('HTTP ' + response.status);
        throw new Error('SD.cpp: ' + options.what + ' failed: ' + detail);
    }

    return body || {};
}

function login(server, credential, timeout) {
    const session = call({
        method: 'POST',
        url: server + '/auth/login',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({
            username: credential.username,
            password: credential.password
        }),
        timeout: timeout,
        what: 'signing in'
    });

    if (!session.token) {
        throw new Error('SD.cpp: the server accepted the login but returned no token');
    }
    return session.token;
}

// Width, steps, cfg_scale and friends are architecture defaults: the server
// fills them from the loaded model's preset when the field is absent. Sending
// an empty box as 0 or "" would override that preset with nonsense, so a field
// the user did not fill must not appear in the body at all.
//
// The test is emptiness, never truthiness. seed 0 and clip_skip 0 are both
// legitimate values that a truthy check would silently drop.
function putIfSet(target, key, value) {
    if (value === undefined || value === null || value === '') {
        return;
    }
    if (typeof value === 'number' && !isFinite(value)) {
        return;
    }
    target[key] = value;
}

async function execute(config, input, context) {
    const server = normalizeServer(config.serverUrl);
    const operation = config.operation || 'txt2img';
    const timeout = config.timeout || 30000;

    if (['txt2img', 'img2img', 'txt2vid', 'upscale'].indexOf(operation) === -1) {
        throw new Error('SD.cpp: unknown operation "' + operation + '"');
    }

    const credential = readCredential(config.credentialId);
    const token = login(server, credential, timeout);

    const body = {};

    if (operation === 'upscale') {
        // Upscale is not a generation call - it takes an image and the upscaler
        // slot, and none of the prompt or sampler fields apply.
        putIfSet(body, 'image_base64', config.initImageBase64);
        if (!body.image_base64) {
            throw new Error('SD.cpp: the upscale operation needs an init image, ' +
                'given as base64 in the Init Image field');
        }
        putIfSet(body, 'upscale_factor', config.upscaleFactor);
        putIfSet(body, 'title', config.title);
    } else {
        putIfSet(body, 'prompt', config.prompt);
        if (!body.prompt) {
            throw new Error('SD.cpp: ' + operation + ' needs a prompt');
        }
        putIfSet(body, 'negative_prompt', config.negativePrompt);
        putIfSet(body, 'width', config.width);
        putIfSet(body, 'height', config.height);
        putIfSet(body, 'steps', config.steps);
        putIfSet(body, 'cfg_scale', config.cfgScale);
        putIfSet(body, 'sampler', config.sampler);
        putIfSet(body, 'scheduler', config.scheduler);
        putIfSet(body, 'seed', config.seed);
        putIfSet(body, 'batch_count', config.batchCount);
        putIfSet(body, 'clip_skip', config.clipSkip);
        putIfSet(body, 'title', config.title);

        if (operation === 'img2img' || operation === 'txt2vid') {
            putIfSet(body, 'init_image_base64', config.initImageBase64);
            putIfSet(body, 'strength', config.strength);
        }
        if (operation === 'img2img') {
            putIfSet(body, 'mask_image_base64', config.maskImageBase64);
        }
        if (operation === 'txt2vid') {
            putIfSet(body, 'video_frames', config.videoFrames);
            putIfSet(body, 'fps', config.fps);
        }
        if (operation === 'img2img' && !body.init_image_base64) {
            throw new Error('SD.cpp: img2img needs an init image, given as base64 in the ' +
                'Init Image field');
        }
    }

    // The API has around seventy generation fields and this node exposes the
    // common ones. Anything else the user names here goes straight through, so
    // a new server field does not need a node change to be reachable.
    const extra = config.extraOptions;
    if (extra && typeof extra === 'object') {
        const keys = Object.keys(extra);
        for (let i = 0; i < keys.length; i++) {
            putIfSet(body, keys[i], extra[keys[i]]);
        }
    }

    const queued = call({
        method: 'POST',
        url: server + '/' + operation,
        headers: {
            'Content-Type': 'application/json',
            'Authorization': 'Bearer ' + token
        },
        body: JSON.stringify(body),
        timeout: timeout,
        what: 'queueing the ' + operation + ' job'
    });

    if (!queued.job_id) {
        throw new Error('SD.cpp: the ' + operation + ' job was accepted but no job id came back');
    }

    smartbotic.log.info('SD.cpp: queued ' + operation + ' job ' + queued.job_id +
        ' at position ' + (queued.position !== undefined ? queued.position : 'unknown'));

    return {
        jobId: queued.job_id,
        status: queued.status || 'pending',
        position: queued.position !== undefined ? queued.position : -1,
        operation: operation,
        request: body
    };
}

module.exports = { configSchema, inputSchema, outputSchema, execute };