import { z } from "zod";

export const compressionModeSchema = z.enum([
  "off",
  "lite",
  "standard",
  "aggressive",
  "ultra",
  "rtk",
  "stacked",
]);

export const cavemanIntensitySchema = z.enum(["lite", "full", "ultra"]);
export const rtkIntensitySchema = z.enum(["minimal", "standard", "aggressive"]);
export const rtkRawOutputRetentionSchema = z.enum(["never", "failures", "always"]);

export const cavemanConfigSchema = z
  .object({
    enabled: z.boolean().optional(),
    compressRoles: z.array(z.enum(["user", "assistant", "system"])).optional(),
    skipRules: z.array(z.string()).optional(),
    minMessageLength: z.number().int().min(0).optional(),
    preservePatterns: z.array(z.string()).optional(),
    intensity: cavemanIntensitySchema.optional(),
  })
  .strict();

export const cavemanOutputModeSchema = z
  .object({
    enabled: z.boolean().optional(),
    intensity: cavemanIntensitySchema.optional(),
    autoClarity: z.boolean().optional(),
  })
  .strict();

export const outputStyleSelectionSchema = z
  .object({
    id: z.string().trim().min(1),
    level: cavemanIntensitySchema,
  })
  .strict();

export const rtkConfigSchema = z
  .object({
    enabled: z.boolean().optional(),
    intensity: rtkIntensitySchema.optional(),
    applyToToolResults: z.boolean().optional(),
    applyToCodeBlocks: z.boolean().optional(),
    applyToAssistantMessages: z.boolean().optional(),
    enabledFilters: z.array(z.string()).optional(),
    disabledFilters: z.array(z.string()).optional(),
    maxLinesPerResult: z.number().int().min(0).max(100000).optional(),
    maxCharsPerResult: z.number().int().min(0).max(1000000).optional(),
    deduplicateThreshold: z.number().int().min(2).max(100).optional(),
    customFiltersEnabled: z.boolean().optional(),
    trustProjectFilters: z.boolean().optional(),
    rawOutputRetention: rtkRawOutputRetentionSchema.optional(),
    rawOutputMaxBytes: z.number().int().min(1024).max(10_000_000).optional(),
    enableGrouping: z.boolean().optional(),
    groupingThreshold: z.number().int().min(2).max(100).optional(),
    stripCodeComments: z.boolean().optional(),
    preserveDocstrings: z.boolean().optional(),
  })
  .strict();

// mcpAccessibility tunes how the MCP server trims oversized tool outputs before returning them.
// The schema only enforces structural validity (positive integers / booleans); the numeric floors
// (e.g. maxTextChars below the truncation-tail reserve) are owned by clampMcpAccessibilityConfig
// on the write path, which folds out-of-range values back to the safe defaults. All fields are
// optional so the settings sub-route can apply a partial merge over the current config.
export const mcpAccessibilityConfigSchema = z
  .object({
    enabled: z.boolean().optional(),
    maxTextChars: z.number().int().min(1).optional(),
    collapseThreshold: z.number().int().min(1).optional(),
    collapseKeepHead: z.number().int().min(0).optional(),
    collapseKeepTail: z.number().int().min(0).optional(),
    minLengthToProcess: z.number().int().min(1).optional(),
  })
  .strict();

export const languageConfigSchema = z
  .object({
    enabled: z.boolean().optional(),
    defaultLanguage: z.string().trim().min(1).optional(),
    autoDetect: z.boolean().optional(),
    enabledPacks: z.array(z.string().trim().min(1)).optional(),
  })
  .strict();

// Context Editing is a provider-delegated compression mode (Claude/Anthropic only):
// the provider clears old tool-use blocks server-side. This config only carries the
// on/off flag; the request-time header/body injection is a separate slice.
export const contextEditingConfigSchema = z
  .object({
    enabled: z.boolean().optional(),
  })
  .strip();

export const aggressiveConfigSchema = z
  .object({
    thresholds: z
      .object({
        fullSummary: z.number().int().min(1).max(100).optional(),
        moderate: z.number().int().min(1).max(100).optional(),
        light: z.number().int().min(1).max(100).optional(),
        verbatim: z.number().int().min(1).max(100).optional(),
      })
      .strict()
      .optional(),
    toolStrategies: z
      .object({
        fileContent: z.boolean().optional(),
        grepSearch: z.boolean().optional(),
        shellOutput: z.boolean().optional(),
        json: z.boolean().optional(),
        errorMessage: z.boolean().optional(),
      })
      .strict()
      .optional(),
    summarizerEnabled: z.boolean().optional(),
    maxTokensPerMessage: z.number().int().min(256).max(32768).optional(),
    minSavingsThreshold: z.number().min(0).max(1).optional(),
    preserveSystemPrompt: z.boolean().optional(),
  })
  .strict();

export const ultraConfigSchema = z
  .object({
    enabled: z.boolean().optional(),
    compressionRate: z.number().min(0).max(1).optional(),
    minScoreThreshold: z.number().min(0).max(1).optional(),
    slmFallbackToAggressive: z.boolean().optional(),
    modelPath: z.string().trim().min(1).optional(),
    maxTokensPerMessage: z.number().int().min(0).max(32768).optional(),
    preserveSystemPrompt: z.boolean().optional(),
  })
  .strict();

const noConfigSchema = z.object({}).strict();

export const stackedPipelineStepSchema = z.discriminatedUnion("engine", [
  z
    .object({
      engine: z.literal("lite"),
      intensity: z.literal("lite").optional(),
      config: noConfigSchema.optional(),
    })
    .strict(),
  z
    .object({
      engine: z.literal("caveman"),
      intensity: cavemanIntensitySchema.optional(),
      config: cavemanConfigSchema.optional(),
    })
    .strict(),
  z
    .object({
      engine: z.literal("aggressive"),
      intensity: z.literal("standard").optional(),
      config: aggressiveConfigSchema.optional(),
    })
    .strict(),
  z
    .object({
      engine: z.literal("ultra"),
      intensity: z.literal("ultra").optional(),
      config: ultraConfigSchema.optional(),
    })
    .strict(),
  z
    .object({
      engine: z.literal("rtk"),
      intensity: rtkIntensitySchema.optional(),
      config: rtkConfigSchema.optional(),
    })
    .strict(),
]);

/**
 * Canonical engine → selectable-intensities map for the named-combos pipeline editor
 * (Engine Combos UI). This is the SINGLE source of truth shared by the dashboard
 * dropdowns and `stackedPipelineStepSchema`: every engine/intensity offered here is,
 * by construction, accepted by the API update schema.
 *
 * Do NOT add an engine here that is not a branch of `stackedPipelineStepSchema` — the
 * `PUT /api/context/combos/[id]` route validates against that discriminated union and
 * would reject the payload with HTTP 400 (#4955: the UI previously offered `headroom`,
 * `session-dedup`, `ccr`, `llmlingua`, none of which the union accepts, so selecting
 * one silently failed the save). The parity is guarded by a unit test.
 */
export const STACKED_PIPELINE_ENGINE_INTENSITIES: Record<string, readonly string[]> = {
  rtk: ["minimal", "standard", "aggressive"],
  caveman: ["lite", "full", "ultra"],
  lite: ["lite"],
  aggressive: ["standard"],
  ultra: ["ultra"],
};

export const engineToggleSchema = z.object({
  enabled: z.boolean(),
  level: z.string().optional(),
});

export const compressionSettingsUpdateSchema = z
  .object({
    enabled: z.boolean().optional(),
    defaultMode: compressionModeSchema.optional(),
    autoTriggerMode: compressionModeSchema.optional(),
    autoTriggerTokens: z.number().int().min(0).optional(),
    cacheMinutes: z.number().int().min(1).max(60).optional(),
    preserveSystemPrompt: z.boolean().optional(),
    mcpDescriptionCompressionEnabled: z.boolean().optional(),
    comboOverrides: z.record(z.string(), compressionModeSchema).optional(),
    compressionComboId: z.string().trim().min(1).nullable().optional(),
    stackedPipeline: z.array(stackedPipelineStepSchema).optional(),
    cavemanConfig: cavemanConfigSchema.optional(),
    cavemanOutputMode: cavemanOutputModeSchema.optional(),
    outputStyles: z.array(outputStyleSelectionSchema).optional(),
    rtkConfig: rtkConfigSchema.optional(),
    languageConfig: languageConfigSchema.optional(),
    aggressive: aggressiveConfigSchema.optional(),
    ultra: ultraConfigSchema.optional(),
    contextEditing: contextEditingConfigSchema.optional(),
    engines: z.record(z.string(), engineToggleSchema).optional(),
    enginesExplicit: z.boolean().optional(),
    activeComboId: z.string().nullable().optional(),
    ultraEngine: z.enum(["heuristic", "slm"]).optional(),
    ultraSlmPrewarm: z.boolean().optional(),
  })
  .strict();

export const compressionPreviewConfigSchema = compressionSettingsUpdateSchema;