// Package briefing builds prompt-facing module values.
package briefing

import (
	"time"

	"gitea.maximumdirect.net/eric/weatherreporter/internal/report"
	"gitea.maximumdirect.net/eric/weatherreporter/internal/timeutil"
	"gitea.maximumdirect.net/eric/weatherreporter/internal/weatherdata"
)

// PreparedIdentity is the single prepared authority for report identity,
// timing, configuration context, and source warnings.
type PreparedIdentity struct {
	RunID            string                      `json:"runId"`
	ReportID         report.ID                   `json:"reportId"`
	Variant          string                      `json:"variant,omitempty"`
	PromptID         string                      `json:"promptId"`
	GeneratedAt      time.Time                   `json:"generatedAt"`
	Units            string                      `json:"units"`
	Timezone         string                      `json:"timezone"`
	ValidPeriod      timeutil.Period             `json:"validPeriod"`
	Location         *LocationContext            `json:"location,omitempty"`
	SourceLocationID string                      `json:"sourceLocationId,omitempty"`
	SourceLocation   string                      `json:"sourceLocation,omitempty"`
	SourceWarnings   []weatherdata.SourceWarning `json:"sourceWarnings,omitempty"`
}

type LocationContext struct {
	ID       string `json:"id,omitempty"`
	Name     string `json:"name,omitempty"`
	Region   string `json:"region,omitempty"`
	Timezone string `json:"timezone,omitempty"`
}

type BuildContext struct {
	Resolved report.Resolved
	Bundle   *weatherdata.Bundle
	Units    string
	Timezone string
	Location *LocationContext
}

func BuildPreparedIdentity(ctx BuildContext) PreparedIdentity {
	metadata := ctx.Resolved.Metadata()
	sourceLocationID, sourceLocation := sourceLocation(ctx.Bundle)
	return PreparedIdentity{
		RunID:            metadata.RunID,
		ReportID:         metadata.ReportID,
		Variant:          variantForReport(metadata.ReportID),
		PromptID:         metadata.PromptID,
		GeneratedAt:      metadata.GeneratedAt,
		Units:            ctx.Units,
		Timezone:         ctx.Timezone,
		ValidPeriod:      metadata.ValidPeriod,
		Location:         copyLocation(ctx.Location),
		SourceLocationID: sourceLocationID,
		SourceLocation:   sourceLocation,
		SourceWarnings:   append([]weatherdata.SourceWarning(nil), sourceWarnings(ctx.Bundle)...),
	}
}

func copyLocation(location *LocationContext) *LocationContext {
	if location == nil {
		return nil
	}
	copied := *location
	return &copied
}

func copyBool(value *bool) *bool {
	if value == nil {
		return nil
	}
	copied := *value
	return &copied
}

func copyInt(value *int) *int {
	if value == nil {
		return nil
	}
	copied := *value
	return &copied
}

func copyFloat(value *float64) *float64 {
	if value == nil {
		return nil
	}
	copied := *value
	return &copied
}

func copyTime(value *time.Time) *time.Time {
	if value == nil {
		return nil
	}
	copied := *value
	return &copied
}

func sourceLocation(bundle *weatherdata.Bundle) (string, string) {
	if bundle == nil {
		return "", ""
	}
	for _, run := range []*weatherdata.ForecastRun{bundle.Hourly, bundle.Narrative, bundle.Daily} {
		if run == nil {
			continue
		}
		if run.LocationID != "" || run.LocationName != "" {
			return run.LocationID, run.LocationName
		}
	}
	return "", ""
}

func sourceWarnings(bundle *weatherdata.Bundle) []weatherdata.SourceWarning {
	if bundle == nil {
		return nil
	}
	return bundle.Warnings
}

func variantForReport(id report.ID) string {
	switch id {
	case report.Daily, report.Today:
		return "today"
	case report.Tomorrow:
		return "tomorrow"
	default:
		return ""
	}
}