package app

import (
	"context"
	"fmt"
	"time"

	"gitea.maximumdirect.net/eric/weatherreporter/internal/briefing"
	"gitea.maximumdirect.net/eric/weatherreporter/internal/collect"
	"gitea.maximumdirect.net/eric/weatherreporter/internal/fileutil"
	"gitea.maximumdirect.net/eric/weatherreporter/internal/generatedtext"
	"gitea.maximumdirect.net/eric/weatherreporter/internal/promptexec"
	"gitea.maximumdirect.net/eric/weatherreporter/internal/promptinput"
	"gitea.maximumdirect.net/eric/weatherreporter/internal/report"
	"gitea.maximumdirect.net/eric/weatherreporter/internal/state"
)

type promptReportRequest struct {
	GenerateRequest
	Resolved    report.Resolved
	Collection  collect.Result
	Inspection  PromptInspectionResult
	DebugWriter *state.PromptDebugWriter
	noNotify    bool
}

func generatePromptReport(ctx context.Context, req promptReportRequest) (*ReportResult, error) {
	bundle := req.Collection.Bundle
	if bundle == nil {
		return nil, fmt.Errorf("collected weather bundle is required")
	}
	store := req.Store
	var err error
	if store == nil {
		store, err = defaultStore(req.Config)
		if err != nil {
			return nil, err
		}
	}
	paths, err := store.Paths(req.Resolved)
	if err != nil {
		return nil, err
	}
	result := &ReportResult{}

	priorSnapshot, err := store.FindPriorSnapshot(ctx, req.Resolved)
	if err != nil {
		return result, err
	}
	reportFacts, err := BuildReportFacts(ModuleSnapshotRequest{Config: req.Config, Resolved: req.Resolved}, bundle)
	if err != nil {
		return result, generatedReportError(req.Resolved, req.Resolved.Metadata().RunID, "build report facts", err)
	}
	moduleSnapshot, err := BuildModuleSnapshotFromFacts(ModuleSnapshotRequest{Config: req.Config, Resolved: req.Resolved}, reportFacts)
	if err != nil {
		return result, generatedReportError(req.Resolved, req.Resolved.Metadata().RunID, "build module snapshot", err)
	}
	moduleSnapshotPath, err := store.SaveModuleSnapshot(ctx, req.Resolved, moduleSnapshot)
	if err != nil {
		return result, err
	}
	result.ModuleSnapshot = moduleSnapshot
	result.ModuleSnapshotPath = moduleSnapshotPath
	result.PriorSnapshot = priorSnapshot

	recent, err := recentChanges(ctx, store, priorSnapshot, req.Resolved.Definition.ID, moduleSnapshot, req.Config.RecentChange)
	if err != nil {
		return result, err
	}
	result.RecentChanges = recent
	briefingMetadata := briefing.BuildMetadata(briefingBuildContext(req.Config, req.Resolved, reportFacts.Collected))
	metadata := state.BuildPromptMetadataFromBriefingMetadata(req.Resolved, briefingMetadata, state.ArtifactPaths{
		ModuleSnapshot: moduleSnapshotPath,
		Metadata:       paths.Metadata,
	})
	result.Metadata = metadata
	dataPackage, err := promptinput.Build(promptinput.BuildRequest{
		Metadata:      promptMetadata(metadata),
		Modules:       moduleSnapshot,
		RecentChanges: recent,
	})
	if err != nil {
		return result, generatedReportError(req.Resolved, metadata.RunID, "build data package", err)
	}
	data, err := promptinput.MarshalYAML(dataPackage)
	if err != nil {
		return result, err
	}
	dataPackagePath, err := store.SaveDataPackageBytes(ctx, req.Resolved, data)
	if err != nil {
		return result, err
	}
	metadata.DataPackagePath = dataPackagePath
	result.DataPackage = dataPackage
	result.DataPackagePath = dataPackagePath
	result.Metadata = metadata

	handler, err := generatedtext.LookupDefinition(req.Resolved.Definition)
	if err != nil {
		return result, generatedReportError(req.Resolved, metadata.RunID, "lookup generated text catalog", err)
	}

	prepared := false
	callbackFailed := false
	debugRef := state.PromptDebugRef{
		ReportID:  req.Resolved.Definition.ID,
		ValidDate: req.Resolved.ValidPeriod.Start.Format("2006-01-02"),
		RunID:     metadata.RunID,
	}
	callback := func(preparation promptexec.Preparation, debug *promptexec.PreparationDebug) error {
		artifact := state.PromptPreparationArtifact{
			SchemaVersion:   state.PromptPreparationSchemaVersion,
			Status:          state.PromptPreparationSucceeded,
			ReportID:        req.Resolved.Definition.ID,
			RunID:           metadata.RunID,
			PromptID:        req.Inspection.PromptID,
			PromptVersion:   req.Inspection.PromptVersion,
			DataPackagePath: dataPackagePath,
			Preparation:     &preparation,
			StartedAt:       preparation.StartedAt,
			EndedAt:         preparation.EndedAt,
			Duration:        preparation.Duration,
		}
		path, err := store.SavePromptPreparation(ctx, req.Resolved, artifact)
		if err != nil {
			callbackFailed = true
			return err
		}
		prepared = true
		result.PreparationPath = path
		metadata.PreparationPath = path
		result.Metadata = metadata
		debugPath, err := req.DebugWriter.WritePreparation(debugRef, preparation, debug)
		if err != nil {
			callbackFailed = true
			return promptDebugWriteError(err)
		}
		if debugPath != "" {
			result.LLMDebugPath = debugPath
		}
		metadataPath, err := store.SaveMetadata(ctx, metadata)
		if err != nil {
			callbackFailed = true
			return err
		}
		result.Metadata = metadata
		result.MetadataPath = metadataPath
		return nil
	}
	execution, executeErr := req.Executor.Execute(ctx, promptexec.ExecuteRequest{
		PromptID:        req.Inspection.PromptID,
		PromptVersion:   req.Inspection.PromptVersion,
		ProfileID:       req.Inspection.ProfileID,
		DataPackage:     data,
		DataPackagePath: dataPackagePath,
		CaptureDebug:    req.DebugWriter.Enabled(),
	}, callback)
	if executeErr != nil {
		if callbackFailed {
			return result, executeErr
		}
		executeErr = classifiedPromptError("prompt execution failed", executeErr)
		if !prepared {
			artifact := state.PromptPreparationArtifact{
				SchemaVersion: state.PromptPreparationSchemaVersion, Status: state.PromptPreparationFailed,
				ReportID: req.Resolved.Definition.ID, RunID: metadata.RunID, PromptID: req.Inspection.PromptID,
				PromptVersion: req.Inspection.PromptVersion, DataPackagePath: dataPackagePath,
				StartedAt: time.Now(), EndedAt: time.Now(), Error: state.NewPromptArtifactError(executeErr),
			}
			path, saveErr := store.SavePromptPreparation(ctx, req.Resolved, artifact)
			if saveErr != nil {
				return result, saveErr
			}
			metadata.PreparationPath = path
			result.PreparationPath = path
			result.Metadata = metadata
			metadataPath, saveErr := store.SaveMetadata(ctx, metadata)
			if saveErr != nil {
				return result, saveErr
			}
			result.MetadataPath = metadataPath
			return result, generatedReportError(req.Resolved, metadata.RunID, "prepare prompt", executeErr)
		}
		if promptexec.CategoryOf(executeErr) != "" {
			artifact := failedPromptExecutionArtifact(req.Resolved, metadata, req.Inspection, executeErr)
			path, saveErr := store.SavePromptExecution(ctx, req.Resolved, artifact)
			if saveErr != nil {
				return result, saveErr
			}
			metadata.ExecutionPath = path
			result.ExecutionPath = path
			result.Metadata = metadata
			metadataPath, saveErr := store.SaveMetadata(ctx, metadata)
			if saveErr != nil {
				return result, saveErr
			}
			result.MetadataPath = metadataPath
		}
		return result, generatedReportError(req.Resolved, metadata.RunID, "execute prompt", executeErr)
	}
	if execution == nil {
		err := promptexec.NewError(promptexec.Generation, "prompt executor returned no execution", nil)
		artifact := failedPromptExecutionArtifact(req.Resolved, metadata, req.Inspection, err)
		executionPath, saveErr := store.SavePromptExecution(ctx, req.Resolved, artifact)
		if saveErr != nil {
			return result, saveErr
		}
		metadata.ExecutionPath = executionPath
		result.ExecutionPath = executionPath
		result.Metadata = metadata
		metadataPath, saveErr := store.SaveMetadata(ctx, metadata)
		if saveErr != nil {
			return result, saveErr
		}
		result.MetadataPath = metadataPath
		return result, generatedReportError(req.Resolved, metadata.RunID, "execute prompt", err)
	}
	debugPath, err := req.DebugWriter.WriteExecution(debugRef, *execution)
	if err != nil {
		return result, generatedReportError(req.Resolved, metadata.RunID, "write prompt debug", promptDebugWriteError(err))
	}
	if debugPath != "" {
		result.LLMDebugPath = debugPath
	}

	if execution.Validation.Status != promptexec.ValidationPassed && execution.Validation.Status != promptexec.ValidationFailed {
		err := promptexec.NewError(promptexec.OperationalValidation, "prompt execution did not complete validation", nil)
		artifact := failedPromptExecutionArtifact(req.Resolved, metadata, req.Inspection, err)
		executionPath, saveErr := store.SavePromptExecution(ctx, req.Resolved, artifact)
		if saveErr != nil {
			return result, saveErr
		}
		metadata.ExecutionPath = executionPath
		result.ExecutionPath = executionPath
		result.Metadata = metadata
		metadataPath, saveErr := store.SaveMetadata(ctx, metadata)
		if saveErr != nil {
			return result, saveErr
		}
		result.MetadataPath = metadataPath
		return result, generatedReportError(req.Resolved, metadata.RunID, "validate prompt execution", err)
	}
	rawPath, err := store.SaveGeneratedTextRaw(ctx, req.Resolved, execution.RawOutput)
	if err != nil {
		return result, err
	}
	result.GeneratedTextRawPath = rawPath
	metadata.GeneratedTextRawPath = rawPath
	result.Metadata = metadata
	executionArtifact := state.PromptExecutionArtifact{
		SchemaVersion: state.PromptExecutionSchemaVersion,
		ReportID:      req.Resolved.Definition.ID, RunID: metadata.RunID,
		PromptID: req.Inspection.PromptID, PromptVersion: req.Inspection.PromptVersion,
		Provenance: ptr(state.PromptExecutionProvenanceFrom(*execution)), Validation: &execution.Validation,
		Paths:     state.PromptExecutionPaths{RawOutputPath: rawPath},
		StartedAt: execution.StartedAt, EndedAt: execution.EndedAt, Duration: execution.Duration,
	}
	if execution.Validation.Status == promptexec.ValidationPassed {
		executionArtifact.Status = state.PromptExecutionSucceeded
	} else {
		executionArtifact.Status = state.PromptExecutionValidationRejected
	}
	executionPath, err := store.SavePromptExecution(ctx, req.Resolved, executionArtifact)
	if err != nil {
		return result, err
	}
	metadata.ExecutionPath = executionPath
	result.ExecutionPath = executionPath
	result.Metadata = metadata
	metadataPath, err := store.SaveMetadata(ctx, metadata)
	if err != nil {
		return result, err
	}
	result.MetadataPath = metadataPath
	if execution.Validation.Status == promptexec.ValidationFailed {
		return result, generatedReportError(req.Resolved, metadata.RunID, "validate prompt execution", promptexec.NewError(promptexec.ValidationRejected, "prompt output did not satisfy its schema", nil))
	}

	generatedText, normalized, err := handler.Validate(execution.RawOutput)
	if err != nil {
		return result, generatedReportError(req.Resolved, metadata.RunID, "validate generated text", err)
	}
	generatedTextPath, err := store.SaveGeneratedText(ctx, req.Resolved, normalized)
	if err != nil {
		return result, err
	}
	metadata.GeneratedTextPath = generatedTextPath
	result.GeneratedTextPath = generatedTextPath
	result.Metadata = metadata
	executionArtifact.Paths.GeneratedTextPath = generatedTextPath
	if _, err := store.SavePromptExecution(ctx, req.Resolved, executionArtifact); err != nil {
		return result, err
	}
	metadataPath, err = store.SaveMetadata(ctx, metadata)
	if err != nil {
		return result, err
	}
	result.MetadataPath = metadataPath

	renderContext, err := handler.BuildRenderContext(briefingMetadata, moduleSnapshot, reportFacts.Collected, reportFacts.Derived, generatedText)
	if err != nil {
		return result, generatedReportError(req.Resolved, metadata.RunID, "build render context", err)
	}
	renderContextPath, err := store.SaveRenderContext(ctx, req.Resolved, renderContext)
	if err != nil {
		return result, err
	}
	metadata.RenderContextPath = renderContextPath
	result.RenderContextPath = renderContextPath
	result.Metadata = metadata
	executionArtifact.Paths.RenderContextPath = renderContextPath
	if _, err := store.SavePromptExecution(ctx, req.Resolved, executionArtifact); err != nil {
		return result, err
	}
	metadataPath, err = store.SaveMetadata(ctx, metadata)
	if err != nil {
		return result, err
	}
	result.MetadataPath = metadataPath

	rendered, err := handler.Render(renderContext)
	if err != nil {
		return result, generatedReportError(req.Resolved, metadata.RunID, "render template", err)
	}
	reportPath, err := store.PrepareRenderedReport(ctx, req.Resolved)
	if err != nil {
		return result, err
	}
	if err := fileutil.WriteFileAtomic(reportPath, rendered); err != nil {
		return result, err
	}
	result.ReportPath = reportPath
	metadata.RenderedReportPath = reportPath
	result.Metadata = metadata
	executionArtifact.Paths.RenderedReportPath = reportPath
	if _, err := store.SavePromptExecution(ctx, req.Resolved, executionArtifact); err != nil {
		return result, err
	}
	finalized, err := finalizeRenderedReport(ctx, finalizeRenderedReportRequest{
		Config: req.Config, Store: store, Resolved: req.Resolved, Metadata: metadata, MetadataPath: result.MetadataPath,
		ExecutionArtifact: &executionArtifact, ManagedReportPath: reportPath, OutputPath: req.OutputPath,
		Notifier: req.Notifier, noNotify: req.noNotify,
	})
	result.OutputPath, result.NotificationPath = finalized.OutputPath, finalized.NotificationPath
	result.Metadata, result.MetadataPath, result.Notification = finalized.Metadata, finalized.MetadataPath, finalized.Notification
	if err != nil {
		return result, err
	}
	return result, nil
}

func failedPromptExecutionArtifact(resolved report.Resolved, metadata state.Metadata, inspection PromptInspectionResult, err error) state.PromptExecutionArtifact {
	now := time.Now()
	return state.PromptExecutionArtifact{
		SchemaVersion: state.PromptExecutionSchemaVersion, Status: state.PromptExecutionFailed,
		ReportID: resolved.Definition.ID, RunID: metadata.RunID, PromptID: inspection.PromptID,
		PromptVersion: inspection.PromptVersion, StartedAt: now, EndedAt: now,
		Error: state.NewPromptArtifactError(err),
	}
}

func classifiedPromptError(operation string, err error) error {
	if promptexec.CategoryOf(err) != "" {
		return err
	}
	return promptexec.NewError(promptexec.Generation, operation, err)
}

func promptDebugWriteError(err error) error {
	return promptexec.NewError(promptexec.InvalidConfiguration, "write requested prompt debug artifact", err)
}

func ptr[T any](value T) *T { return &value }