package config

import (
	"slices"

	ck "go.maximumdirect.net/configkit"
)

func cloneSelection(value *string) *string {
	if value == nil {
		return nil
	}
	copied := *value
	return &copied
}

func defaultNames(r *ck.Resolution, path ck.Path, target *[]string, inherited []string, reason string, source ck.Path) {
	if !r.IsExplicit(path) {
		ck.Default(r, path, target, slices.Clone(inherited), reason, source)
	}
}

// resolveSettings records root-derived defaults after all explicit assignments.
func resolveSettings(c *Config, r *ck.Resolution) error {
	glossaries := ck.Keys("glossaries")
	protection := ck.Keys("protected_terms")
	defaultNames(r, protection, &c.ProtectedTerms, c.Glossaries, "protection defaults to selected glossaries", glossaries)
	rootValidation := ck.Keys("llm", "validation_profile")
	rootValidationInfo, _ := r.EntryInfo(rootValidation)
	inheritedValidation := r.IsExplicit(rootValidation) && !rootValidationInfo.Null && c.LLM.ValidationProfile != nil
	for i := range c.Pipeline.Stages {
		item := &c.Pipeline.Stages[i]
		base := ck.Keys("pipeline", "stages").Index(i)
		defaultNames(r, base.Key("glossaries"), &item.Glossaries, c.Glossaries, "inherit root glossaries", glossaries)
		defaultNames(r, base.Key("protected_terms"), &item.ProtectedTerms, c.ProtectedTerms, "inherit root protection", protection)
		threshold := ck.Keys("thresholds", item.Module)
		var value float64
		switch item.Module {
		case "glossary":
			value = c.Thresholds.Glossary
		case "homophones":
			value = c.Thresholds.Homophones
		case "spoken_word":
			value = c.Thresholds.SpokenWord
		case "grammar":
			value = c.Thresholds.Grammar
		}
		ck.Default(r, base.Key("confidence_threshold"), &item.ConfidenceThreshold, value, "inherit module threshold", threshold)
		llm := base.Key("llm")
		rootLLM := ck.Keys("llm")
		proposal := llm.Key("proposal_profile")
		ck.Default(r, proposal, &item.LLM.ProposalProfile, cloneSelection(c.LLM.ProposalProfile), "inherit proposal profile", rootLLM.Key("proposal_profile"))
		ck.Default(r, llm.Key("transient_retries"), &item.LLM.TransientRetries, c.LLM.TransientRetries, "inherit retry budget", rootLLM.Key("transient_retries"))
		ck.Default(r, llm.Key("repair_attempts"), &item.LLM.RepairAttempts, c.LLM.RepairAttempts, "inherit repair budget", rootLLM.Key("repair_attempts"))
		ck.Default(r, llm.Key("operation_timeout"), &item.LLM.OperationTimeout, c.LLM.OperationTimeout, "inherit operation timeout", rootLLM.Key("operation_timeout"))
		ck.Default(r, base.Key("validation").Key("max_prompt_tokens"), &item.Validation.MaxPromptTokens, c.Validation.MaxPromptTokens, "inherit validation budget", ck.Keys("validation", "max_prompt_tokens"))
		ck.Default(r, base.Key("context").Key("description"), &item.Context.Description, c.Context.Description, "inherit description", ck.Keys("context", "description"))
		validation := llm.Key("validation_profile")
		info, _ := r.EntryInfo(validation)
		if r.IsExplicit(validation) && info.Null {
			item.LLM.ValidationProfile = cloneSelection(item.LLM.ProposalProfile)
			r.RecordDerivedDefault(validation, "validation defaults to proposal profile", proposal)
		} else if inheritedValidation {
			ck.Default(r, validation, &item.LLM.ValidationProfile, cloneSelection(c.LLM.ValidationProfile), "inherit validation profile", rootValidation)
		} else {
			ck.Default(r, validation, &item.LLM.ValidationProfile, cloneSelection(item.LLM.ProposalProfile), "validation defaults to proposal profile", proposal)
		}
	}
	if r.IsExplicit(rootValidation) && rootValidationInfo.Null {
		c.LLM.ValidationProfile = cloneSelection(c.LLM.ProposalProfile)
		r.RecordDerivedDefault(rootValidation, "validation defaults to proposal profile", ck.Keys("llm", "proposal_profile"))
	} else {
		ck.Default(r, rootValidation, &c.LLM.ValidationProfile, cloneSelection(c.LLM.ProposalProfile), "validation defaults to proposal profile", ck.Keys("llm", "proposal_profile"))
	}
	return nil
}