package report

import (
	"encoding/json"
	"os"
)

// Severity classifies report events.
type Severity string

const (
	SeverityInfo      Severity = "info"
	SeverityWarning   Severity = "warning"
	SeverityCorrected Severity = "corrected"
	SeverityError     Severity = "error"
)

// Event records a validation finding, correction, or pipeline action.
type Event struct {
	Severity Severity `json:"severity"`
	Stage    string   `json:"stage"`
	Module   string   `json:"module"`
	Message  string   `json:"message"`
}

// Report is the deterministic report artifact emitted by the framework.
type Report struct {
	Metadata Metadata `json:"metadata"`
	Events   []Event  `json:"events"`
}

// Metadata records the pipeline configuration that produced the report.
type Metadata struct {
	Application           string   `json:"application"`
	Version               string   `json:"version"`
	InputReader           string   `json:"input_reader"`
	InputFiles            []string `json:"input_files"`
	PreprocessingModules  []string `json:"preprocessing_modules"`
	PostprocessingModules []string `json:"postprocessing_modules"`
	OutputModules         []string `json:"output_modules"`
}

// Info constructs an informational report event.
func Info(stage string, module string, message string) Event {
	return Event{
		Severity: SeverityInfo,
		Stage:    stage,
		Module:   module,
		Message:  message,
	}
}

// WriteJSON writes a deterministic JSON report.
func WriteJSON(path string, rpt Report) error {
	file, err := os.Create(path)
	if err != nil {
		return err
	}
	defer file.Close()

	enc := json.NewEncoder(file)
	enc.SetIndent("", "  ")
	return enc.Encode(rpt)
}