# AI image generation pipeline configuration
#
# Consumed exclusively by scripts/content/generate-images.nu (dev tooling).
# NOT merged into site/config/index.ncl — this is not a runtime site config.
#
# Load: nickel export --format json site/config/image-generation.ncl
#       | from json | get image_generation
#
# Sensitive values (OPENAI_API_KEY, GEMINI_API_KEY, ZAI_TOKEN) live in .env — never inline here.
# The active `provider` selects which key the pipeline reads.

let ProviderContract = std.contract.from_validator (fun value =>
  # openai: dall-e-3 / gpt-image-1 via /v1/images/generations
  # gemini: gemini-2.5-flash-image (nano-banana) via :generateContent
  # zhipu:  glm-image (async via task_id) via /api/paas/v4/async/images/generations
  if value == "openai" || value == "gemini" || value == "zhipu" then 'Ok
  else ('Error "Must be 'openai', 'gemini' or 'zhipu'")
) in

let ImageSizeContract = std.contract.from_validator (fun value =>
  # openai/gemini use these dimensions verbatim; zhipu uses 1280x1280
  # (1024x1024 -> 1:1, 1792x1024 -> 16:9, 1024x1792 -> 9:16 for openai/gemini).
  if (std.is_string value) && (
    value == "1024x1024" ||
    value == "1024x1792" ||
    value == "1792x1024" ||
    value == "1280x1280"
  ) then 'Ok
  else ('Error "Must be a valid image dimension: 1024x1024, 1024x1792, 1792x1024 or 1280x1280 (zhipu)")
) in

let ImageQualityContract = std.contract.from_validator (fun value =>
  # dall-e-3:    "standard" | "hd"
  # gpt-image-1: "low" | "medium" | "high"
  # gemini:      "standard" (no quality tiers; value is ignored by the backend)
  # zhipu:      "standard" (no quality tiers; value is ignored by the backend)
  if value == "standard" || value == "hd" || value == "low" || value == "medium" || value == "high" then 'Ok
  else ('Error "Must be 'standard', 'hd' (dall-e-3) or 'low', 'medium', 'high' (gpt-image-1)")
) in

let NonEmptyString = std.contract.from_validator (fun value =>
  if (std.is_string value) && (std.string.length value > 0) then 'Ok
  else ('Error "Must be a non-empty string")
) in

let ImageSizesContract = {
  thumbnail | String | ImageSizeContract,
  feature   | String | ImageSizeContract,
} in

let ImageStylesContract = {
  blog       | String | NonEmptyString,
  recipes    | String | NonEmptyString,
  activities | String | NonEmptyString,
  projects   | String | NonEmptyString,
} in

let ImageGenerationConfig = {
  provider
    | String
    | ProviderContract
    | doc "Provider backend: 'openai' (dall-e-3 / gpt-image-1), 'gemini' (gemini-2.5-flash-image / nano-banana), 'zhipu' (glm-image)",

  model
    | String
    | NonEmptyString
    | doc "Image model. openai: 'dall-e-3' (hd/standard) | 'gpt-image-1' (low/medium/high). gemini: 'gemini-2.5-flash-image'. zhipu: 'glm-image'",

  quality
    | String
    | ImageQualityContract
    | doc "dall-e-3: 'standard' | 'hd'   gpt-image-1: 'low' | 'medium' | 'high'   gemini/zhipu: 'standard' (ignored)",

  templates_dir
    | String
    | NonEmptyString
    | doc "Path to Tera prompt template files relative to project root",

  sizes
    | ImageSizesContract
    | doc "DALL-E image dimensions per image type",

  styles
    | ImageStylesContract
    | doc "Visual style directives per content type — appended to every prompt",
} in

{
  image_generation = {
    # provider = "openai"  -> model "dall-e-3" | "gpt-image-1"
    # provider = "gemini"  -> model "gemini-2.5-flash-image", quality "standard"
    # provider = "zhipu"  -> model "glm-image", size "1280x1280" (only size supported)
    provider      = "openai",
    model         = "dall-e-3",
    quality       = "hd",
    templates_dir = "site/templates/image-prompts",

    sizes = {
      thumbnail = "1024x1024",
      feature   = "1792x1024",
    },

    styles = {
      blog = "Dark terminal/editor aesthetic. Rust-orange (#CE422B) accent on deep charcoal. Code or circuit motifs. No humans. High contrast. 16:9 composition.",
      recipes = "Clean technical blueprint/schematic. Dark navy, crisp white line-art, cyan accent. Engineering diagram feel. No humans. 16:9.",
      activities = "Professional conference keynote. Dark stage, single bold centered composition. Abstract geometric. No stock photos. No humans. 16:9.",
      projects = "Product showcase and brand reveal. Dark background, Rust-orange and slate-blue palette. Technical, premium, minimal. No humans. 16:9.",
    },
  } | ImageGenerationConfig,
}