package config

import (
	"fmt"
	"strings"

	"gitea.maximumdirect.net/eric/narratio/internal/artifactpolicy"
	"gitea.maximumdirect.net/eric/narratio/internal/pathsafe"
)

func validateCampaign(cfg *CampaignConfig) error {
	if cfg == nil {
		return fmt.Errorf("campaign config is required")
	}
	if CampaignID(cfg) == "" {
		return fmt.Errorf("campaign.campaign_id is required")
	}
	if err := pathsafe.ValidateOpaqueSegment(cfg.CampaignID); err != nil {
		return fmt.Errorf("campaign.campaign_id: %w", err)
	}
	if strings.TrimSpace(cfg.Inputs.SpeakersFile) == "" {
		return fmt.Errorf("campaign.inputs.speakers_file is required")
	}
	if strings.TrimSpace(cfg.Inputs.AutocorrectFile) == "" {
		return fmt.Errorf("campaign.inputs.autocorrect_file is required")
	}
	if strings.TrimSpace(cfg.Inputs.GlossaryFile) == "" {
		return fmt.Errorf("campaign.inputs.glossary_file is required")
	}
	if strings.TrimSpace(cfg.Inputs.PartyFile) == "" {
		return fmt.Errorf("campaign.inputs.party_file is required")
	}
	if cfg.Inputs.SpellCatalogFile != "" && strings.TrimSpace(cfg.Inputs.SpellCatalogFile) == "" {
		return fmt.Errorf("campaign.inputs.spell_catalog_file must be non-empty when provided")
	}
	return nil
}

func validateSpool(cfg SpoolConfig) error {
	return nil
}

func validateCache(cfg CacheConfig) error {
	if cfg.S3Audio != nil && *cfg.S3Audio && strings.TrimSpace(cfg.Root) == "" {
		return fmt.Errorf("pipeline.cache.root is required when pipeline.cache.s3_audio is true")
	}
	return nil
}

func validateSession(cfg *SessionConfig) error {
	if err := validateSessionIdentifier("session.session_id", cfg.SessionID, true); err != nil {
		return err
	}
	if err := validateSessionIdentifier("session.previous_session_id", cfg.PreviousSessionID, false); err != nil {
		return err
	}
	if strings.TrimSpace(cfg.PreviousSessionID) != "" && strings.TrimSpace(cfg.PreviousSessionID) == strings.TrimSpace(cfg.SessionID) {
		return fmt.Errorf("session.previous_session_id must not equal session.session_id")
	}
	if strings.TrimSpace(cfg.Campaign) == "" {
		return fmt.Errorf("session.campaign is required")
	}
	if err := pathsafe.ValidateOpaqueSegment(cfg.Campaign); err != nil {
		return fmt.Errorf("session.campaign: %w", err)
	}

	if strings.TrimSpace(cfg.Inputs.SpeakersFile) == "" {
		return fmt.Errorf("session.inputs.speakers_file is required")
	}
	if strings.TrimSpace(cfg.Inputs.AutocorrectFile) == "" {
		return fmt.Errorf("session.inputs.autocorrect_file is required")
	}
	if strings.TrimSpace(cfg.Inputs.GlossaryFile) == "" {
		return fmt.Errorf("session.inputs.glossary_file is required")
	}
	if cfg.Inputs.SpellCatalogFile != "" && strings.TrimSpace(cfg.Inputs.SpellCatalogFile) == "" {
		return fmt.Errorf("session.inputs.spell_catalog_file must be non-empty when provided")
	}

	hasAudioDir := strings.TrimSpace(cfg.Inputs.AudioDir) != ""
	hasAudioFiles := len(cfg.Inputs.AudioFiles) > 0
	hasAudioS3 := cfg.Inputs.AudioS3 != nil
	if hasAudioS3 {
		if strings.TrimSpace(cfg.Inputs.AudioS3.Prefix) == "" {
			return fmt.Errorf("session.inputs.audio_s3.prefix is required when session.inputs.audio_s3 is configured")
		}
		if err := validateRelativeSafePath("session.inputs.audio_s3.prefix", cfg.Inputs.AudioS3.Prefix); err != nil {
			return err
		}
	}
	if hasAudioS3 && (hasAudioDir || hasAudioFiles) {
		return fmt.Errorf("session.inputs.audio_dir/audio_files and session.inputs.audio_s3 are mutually exclusive")
	}
	if !hasAudioDir && !hasAudioFiles && !hasAudioS3 {
		return fmt.Errorf("session.inputs requires audio_dir, at least one audio_files entry, or audio_s3")
	}

	return nil
}

func validateResolvedPartyInputs(cfg *Config) error {
	if cfg == nil || cfg.Session == nil {
		return fmt.Errorf("session config is required")
	}
	if cfg.Party.Canonical == nil {
		return fmt.Errorf("canonical party data is required")
	}
	if cfg.Party.Source.Source != "campaign_config" {
		return fmt.Errorf("canonical party must be sourced by campaign_config")
	}
	return nil
}

func validateSessionIdentifier(fieldName, value string, required bool) error {
	if strings.TrimSpace(value) == "" {
		if required {
			return fmt.Errorf("%s is required", fieldName)
		}
		return nil
	}
	if err := pathsafe.ValidateOpaqueSegment(value); err != nil {
		return fmt.Errorf("%s: %w", fieldName, err)
	}
	return nil
}

func validateCrossConfig(pipeline *PipelineConfig, session *SessionConfig, stableInputs ResolvedStableInputs) error {
	if pipeline == nil || session == nil {
		return nil
	}
	if pipeline.Notarius != nil && pipeline.Notarius.Enabled {
		for _, selector := range sortedStringKeys(pipeline.Notarius.References) {
			source := pipeline.Notarius.References[selector]
			if source == artifactpolicy.SourceInputSpellCatalog && strings.TrimSpace(stableInputs.SpellCatalogFile.Path) == "" {
				return fmt.Errorf("pipeline.notarius.references.%s requires campaign.inputs.spell_catalog_file or session.inputs.spell_catalog_file", selector)
			}
		}
	}

	audioS3Enabled := session.Inputs.AudioS3 != nil
	publishUploadEnabled := publishUploadConfiguredForS3(pipeline)
	if audioS3Enabled && !strings.EqualFold(strings.TrimSpace(pipeline.Storage.Backend), StorageBackendS3) {
		return fmt.Errorf("pipeline.storage.backend must be s3 when session.inputs.audio_s3 is configured")
	}
	if !audioS3Enabled && !publishUploadEnabled {
		return nil
	}
	if pipeline.Storage.S3 == nil || strings.TrimSpace(pipeline.Storage.S3.Bucket) == "" {
		return fmt.Errorf("pipeline.storage.s3.bucket is required when S3 session audio or publish upload is enabled")
	}
	return nil
}