// 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"
)

type Metadata 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"`
	Sources          []SourceMetadata            `json:"sources,omitempty"`
	SourceWarnings   []weatherdata.SourceWarning `json:"sourceWarnings,omitempty"`
	Alerts           *AlertStatus                `json:"alerts,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 SourceMetadata struct {
	Name       string                      `json:"name"`
	Endpoint   string                      `json:"endpoint,omitempty"`
	FetchedAt  time.Time                   `json:"fetchedAt"`
	IssuedAt   *time.Time                  `json:"issuedAt,omitempty"`
	UpdatedAt  *time.Time                  `json:"updatedAt,omitempty"`
	DataSHA256 string                      `json:"dataSha256,omitempty"`
	Missing    bool                        `json:"missing,omitempty"`
	Warnings   []weatherdata.SourceWarning `json:"warnings,omitempty"`
}

type AlertStatus struct {
	Checked       bool `json:"checked"`
	ActiveCount   int  `json:"activeCount"`
	RelevantCount int  `json:"relevantCount"`
	Missing       bool `json:"missing,omitempty"`
}

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

func BuildMetadata(ctx BuildContext) Metadata {
	metadata := ctx.Resolved.Metadata()
	sourceLocationID, sourceLocation := sourceLocation(ctx.Bundle)
	return Metadata{
		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,
		Sources:          sourceMetadata(ctx.Bundle),
		SourceWarnings:   sourceWarnings(ctx.Bundle),
		Alerts:           alertStatus(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 sourceMetadata(bundle *weatherdata.Bundle) []SourceMetadata {
	if bundle == nil {
		return nil
	}
	out := make([]SourceMetadata, 0, len(bundle.Sources))
	for _, source := range bundle.Sources {
		out = append(out, SourceMetadata{
			Name:       source.Name,
			Endpoint:   source.Endpoint,
			FetchedAt:  source.FetchedAt,
			IssuedAt:   source.IssuedAt,
			UpdatedAt:  source.UpdatedAt,
			DataSHA256: source.DataSHA256,
			Missing:    source.Missing,
			Warnings:   source.Warnings,
		})
	}
	return out
}

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

func alertStatus(bundle *weatherdata.Bundle) *AlertStatus {
	if bundle == nil {
		return nil
	}
	status := &AlertStatus{}
	if bundle.Alerts != nil {
		status.Checked = true
		status.ActiveCount = len(bundle.Alerts.Alerts)
	}
	for _, source := range bundle.Sources {
		if source.Name == "alerts" && source.Missing {
			status.Missing = true
			break
		}
	}
	if !status.Checked && !status.Missing {
		return nil
	}
	return status
}

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