package app

import (
	"context"
	"fmt"

	"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/module"
	"gitea.maximumdirect.net/eric/weatherreporter/internal/promptdebug"
	"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/weatherdata"
)

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

type promptReportWorkflow struct {
	ctx              context.Context
	req              promptReportRequest
	result           *ReportResult
	briefingMetadata briefing.Metadata
	reportFacts      ReportFacts
	moduleSnapshot   module.Snapshot
	dataPackage      []byte
	handler          generatedtext.Handler
	debugRef         promptdebug.PromptDebugRef
	callbackFailed   bool
}

func generatePromptReport(ctx context.Context, req promptReportRequest) (*ReportResult, error) {
	workflow, err := newPromptReportWorkflow(ctx, req)
	if err != nil {
		return nil, err
	}
	if err := workflow.buildInputs(); err != nil {
		return workflow.result, err
	}
	execution, err := workflow.executePrompt()
	if err != nil {
		if workflow.callbackFailed {
			return workflow.result, err
		}
		return workflow.result, workflow.reportError("execute prompt", classifiedPromptError("prompt execution failed", err))
	}
	if execution == nil {
		return workflow.result, workflow.reportError("execute prompt", promptexec.NewError(promptexec.Generation, "prompt executor returned no execution", nil))
	}
	workflow.result.ValidationStatus = execution.Validation.Status
	if err := workflow.writeExecutionDebug(*execution); err != nil {
		return workflow.result, err
	}
	if execution.Validation.Status != promptexec.ValidationPassed && execution.Validation.Status != promptexec.ValidationFailed {
		return workflow.result, workflow.reportError("validate prompt execution", promptexec.NewError(promptexec.OperationalValidation, "prompt execution did not complete validation", nil))
	}
	if execution.Validation.Status == promptexec.ValidationFailed {
		return workflow.result, workflow.reportError("validate prompt execution", promptexec.NewError(promptexec.ValidationRejected, "prompt output did not satisfy its schema", nil))
	}
	return workflow.renderAndPublish(execution.RawOutput)
}

func newPromptReportWorkflow(ctx context.Context, req promptReportRequest) (*promptReportWorkflow, error) {
	if req.Collection.Bundle == nil {
		return nil, fmt.Errorf("collected weather bundle is required")
	}
	result := req.Result
	if result == nil {
		result = initialReportResult(req.GenerateRequest, req.Resolved, req.Inspection)
	}
	return &promptReportWorkflow{
		ctx: ctx, req: req,
		result: result,
	}, nil
}

func initialReportResult(req GenerateRequest, resolved report.Resolved, inspection PromptInspectionResult) *ReportResult {
	metadata := resolved.Metadata()
	return &ReportResult{
		ReportID: resolved.Definition.ID, ReportName: resolved.Definition.Name,
		PromptID: resolved.Definition.PromptID, PromptVersion: resolved.Definition.PromptVersion,
		RunID: metadata.RunID, GeneratedAt: metadata.GeneratedAt, Timezone: req.Config.WeatherAPI.Timezone,
		ValidPeriod: metadata.ValidPeriod,
		ProfileID:   inspection.ProfileID, BackendID: inspection.BackendID, ModelName: inspection.ModelName,
	}
}

func (w *promptReportWorkflow) buildInputs() error {
	var err error
	w.reportFacts, err = BuildReportFacts(ModuleSnapshotRequest{Config: w.req.Config, Resolved: w.req.Resolved}, w.req.Collection.Bundle)
	if err != nil {
		return w.reportError("build report facts", err)
	}
	w.moduleSnapshot, err = BuildModuleSnapshotFromFacts(ModuleSnapshotRequest{Config: w.req.Config, Resolved: w.req.Resolved}, w.reportFacts)
	if err != nil {
		return w.reportError("build module snapshot", err)
	}
	w.briefingMetadata = briefing.BuildMetadata(briefingBuildContext(w.req.Config, w.req.Resolved, w.reportFacts.Collected))
	w.result.SourceWarnings = append([]weatherdata.SourceWarning(nil), w.briefingMetadata.SourceWarnings...)
	dataPackage, err := promptinput.Build(promptinput.BuildRequest{Metadata: promptMetadata(w.briefingMetadata), Modules: w.moduleSnapshot})
	if err != nil {
		return w.reportError("build data package", err)
	}
	w.dataPackage, err = promptinput.MarshalYAML(dataPackage)
	if err != nil {
		return w.reportError("marshal data package", err)
	}
	w.handler, err = generatedtext.LookupDefinition(w.req.Resolved.Definition)
	if err != nil {
		return w.reportError("lookup generated text catalog", err)
	}
	w.debugRef = promptdebug.PromptDebugRef{ReportID: w.result.ReportID, ValidDate: w.req.Resolved.ValidPeriod.Start.Format("2006-01-02"), RunID: w.result.RunID}
	return nil
}

func (w *promptReportWorkflow) executePrompt() (*promptexec.Execution, error) {
	captureDebug := w.req.DebugWriter != nil && w.req.DebugWriter.Enabled()
	return w.req.Executor.Execute(w.ctx, promptexec.ExecuteRequest{PromptID: w.req.Inspection.PromptID, PromptVersion: w.req.Inspection.PromptVersion, ProfileID: w.req.Inspection.ProfileID, DataPackage: w.dataPackage, CaptureDebug: captureDebug}, w.writePreparationDebug)
}

func (w *promptReportWorkflow) writePreparationDebug(preparation promptexec.Preparation, debug *promptexec.PreparationDebug) error {
	w.result.ProfileID, w.result.BackendID, w.result.ModelName = preparation.ProfileID, preparation.BackendID, preparation.ModelName
	if w.req.DebugWriter == nil {
		return nil
	}
	path, err := w.req.DebugWriter.WritePreparation(w.debugRef, preparation, debug)
	if err != nil {
		w.callbackFailed = true
		return promptDebugWriteError(err)
	}
	w.result.LLMDebugPath = path
	return nil
}

func (w *promptReportWorkflow) writeExecutionDebug(execution promptexec.Execution) error {
	if w.req.DebugWriter == nil {
		return nil
	}
	path, err := w.req.DebugWriter.WriteExecution(w.debugRef, execution)
	if err != nil {
		return w.reportError("write prompt debug", promptDebugWriteError(err))
	}
	if path != "" {
		w.result.LLMDebugPath = path
	}
	return nil
}

func (w *promptReportWorkflow) renderAndPublish(raw []byte) (*ReportResult, error) {
	generatedText, _, err := w.handler.Validate(raw)
	if err != nil {
		return w.result, w.reportError("validate generated text", err)
	}
	renderContext, err := w.handler.BuildRenderContext(w.briefingMetadata, w.moduleSnapshot, w.reportFacts.Collected, w.reportFacts.Derived, generatedText)
	if err != nil {
		return w.result, w.reportError("build render context", err)
	}
	rendered, err := w.handler.Render(renderContext)
	if err != nil {
		return w.result, w.reportError("render template", err)
	}
	if err := fileutil.WriteFileAtomic(w.req.OutputPath, rendered); err != nil {
		return w.result, err
	}
	w.result.OutputPath = w.req.OutputPath
	if w.req.noNotify {
		return w.result, nil
	}
	notification, err := notifyReport(w.ctx, w.req.Config, w.req.Resolved, w.result.OutputPath, w.result.RunID, w.result.GeneratedAt, w.req.Notifier)
	w.result.Notification = notification
	if err != nil {
		return w.result, err
	}
	return w.result, nil
}

func (w *promptReportWorkflow) reportError(operation string, err error) error {
	return generatedReportError(w.req.Resolved, w.result.RunID, operation, 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)
}