package checker

import (
	"context"
	"fmt"

	sdk "git.happydns.org/checker-sdk-go/checker"
)

func NewSectionRule(section, label string, defaultMin float64) sdk.CheckRule {
	return &sectionRule{section: section, label: label, defaultMin: defaultMin}
}

type sectionRule struct {
	section    string
	label      string
	defaultMin float64
}

func (r *sectionRule) Name() string { return "happydeliver.score." + r.section }

func (r *sectionRule) Description() string {
	return fmt.Sprintf("Verify happyDeliver's %s score is above the configured minimum.", r.label)
}

func (r *sectionRule) optionID() string { return "min_score_" + r.section }

func (r *sectionRule) Options() sdk.CheckerOptionsDocumentation {
	return sdk.CheckerOptionsDocumentation{
		UserOpts: []sdk.CheckerOptionDocumentation{
			{
				Id:          r.optionID(),
				Type:        "number",
				Label:       fmt.Sprintf("Minimum %s score", r.label),
				Description: fmt.Sprintf("Minimum acceptable score (0-100) for the %s section.", r.label),
				Default:     r.defaultMin,
			},
		},
	}
}

func (r *sectionRule) Evaluate(ctx context.Context, obs sdk.ObservationGetter, opts sdk.CheckerOptions) []sdk.CheckState {
	var data HappyDeliverData
	if err := obs.Get(ctx, ObservationKeyHappyDeliver, &data); err != nil {
		return []sdk.CheckState{{
			Status:  sdk.StatusError,
			Message: fmt.Sprintf("Failed to read happyDeliver observation: %v", err),
			Code:    "happydeliver.observation.error",
		}}
	}
	if data.Phase != "ok" || data.Scores == nil {
		return []sdk.CheckState{{
			Status:  sdk.StatusInfo,
			Message: "No happyDeliver report available yet",
			Code:    "happydeliver.score.unavailable",
			Subject: r.section,
		}}
	}
	score, ok := data.Scores[r.section]
	if !ok {
		return []sdk.CheckState{{
			Status:  sdk.StatusInfo,
			Message: fmt.Sprintf("happyDeliver report has no %s score", r.label),
			Code:    "happydeliver.score.missing",
			Subject: r.section,
		}}
	}
	threshold := sdk.GetFloatOption(opts, r.optionID(), r.defaultMin)
	status := sdk.StatusOK
	if float64(score) < threshold {
		status = sdk.StatusCrit
	}
	return []sdk.CheckState{{
		Status:   status,
		Message:  fmt.Sprintf("%s score: %d (min %.0f, grade %s)", r.label, score, threshold, data.Grades[r.section]),
		Code:     "happydeliver.score." + r.section,
		Subject:  r.section,
		RuleName: r.Name(),
		Meta: map[string]any{
			"score": score,
			"grade": data.Grades[r.section],
			"min":   threshold,
		},
	}}
}

// Surfaces lifecycle failures in the UI when no per-section scores exist yet.
func NewLifecycleRule() sdk.CheckRule { return &lifecycleRule{} }

type lifecycleRule struct{}

func (r *lifecycleRule) Name() string { return "happydeliver.lifecycle" }

func (r *lifecycleRule) Description() string {
	return "Reports happyDeliver lifecycle errors (allocation, send, timeout, fetch)."
}

func (r *lifecycleRule) Evaluate(ctx context.Context, obs sdk.ObservationGetter, opts sdk.CheckerOptions) []sdk.CheckState {
	var data HappyDeliverData
	if err := obs.Get(ctx, ObservationKeyHappyDeliver, &data); err != nil {
		return []sdk.CheckState{{
			Status:  sdk.StatusError,
			Message: fmt.Sprintf("Failed to read happyDeliver observation: %v", err),
			Code:    "happydeliver.observation.error",
		}}
	}
	switch data.Phase {
	case "ok":
		return []sdk.CheckState{{
			Status:  sdk.StatusOK,
			Message: fmt.Sprintf("Message analysed in %.1fs", data.LatencySeconds),
			Code:    "happydeliver.lifecycle.ok",
		}}
	case "allocate":
		return []sdk.CheckState{{
			Status:  sdk.StatusCrit,
			Message: "Failed to allocate a happyDeliver test address: " + data.Error,
			Code:    "happydeliver.api.unavailable",
		}}
	case "send":
		return []sdk.CheckState{{
			Status:  sdk.StatusCrit,
			Message: "Failed to send the test email: " + data.Error,
			Code:    "happydeliver.send.failed",
		}}
	case "timeout":
		return []sdk.CheckState{{
			Status:  sdk.StatusWarn,
			Message: "happyDeliver did not analyse the message before the timeout",
			Code:    "happydeliver.no_message_received",
		}}
	case "wait", "fetch", "parse":
		return []sdk.CheckState{{
			Status:  sdk.StatusCrit,
			Message: "happyDeliver lifecycle error: " + data.Error,
			Code:    "happydeliver." + data.Phase + ".failed",
		}}
	default:
		return []sdk.CheckState{{
			Status:  sdk.StatusInfo,
			Message: "happyDeliver run in unknown phase: " + data.Phase,
			Code:    "happydeliver.lifecycle.unknown",
		}}
	}
}