package releasekit

import (
	"context"
	"errors"
	"fmt"

	"go.maximumdirect.net/releasekit/internal/git"
	"go.maximumdirect.net/releasekit/internal/publish"
)

// PublicationEvidence identifies one attempted publication independently of
// current repository state. Reconciliation uses RepositoryDir as Git's working
// directory, Tag and Endpoint as the observed ref and destination, and the
// captured object IDs to classify the observation. Endpoint may contain
// credentials; treat this value and saved records as sensitive.
type PublicationEvidence struct {
	RepositoryDir   string // Git working-directory context for relative endpoints; empty uses the caller's current directory.
	ModuleDir       string // physical module directory captured for this attempt.
	ModulePath      string // declared module path captured for this attempt.
	Version         string // semantic version selected for this attempt.
	Tag             string // complete Git tag ref selected for this attempt.
	CandidateCommit string // candidate commit captured before publication.
	TagObject       string // annotated tag object ID captured before pushing, when available.
	Endpoint        string // exact effective push endpoint captured for this attempt; may contain credentials.
	Remote          string // remote name supplying supported transport configuration during later observation.
	RecordedAt      string // UTC RFC3339Nano time when this attempt's evidence was initialized, when available.
}

// PublicationReconciliationResult combines saved evidence with one later
// observation. It does not update local or remote state or modify the record.
type PublicationReconciliationResult struct {
	Evidence          PublicationEvidence // original selected evidence.
	State             PublicationState    // published, not_published, conflict, or unknown.
	ObservedTagObject string              // observed remote tag-object ID, when available.
	ObservedCommit    string              // observed peeled commit ID, when available.
}

// PublicationRecoveryError describes an unresolved recovery operation or a
// record/storage failure. Its Error text is credential-safe; Unwrap retains
// the underlying cause for errors.Is and errors.As.
// Kind includes missing_evidence, invalid_evidence, canceled, endpoint_changed,
// transport_configuration, remote_observation, inconsistent_observation,
// record_format, record_read, record_write, and storage_enumeration.
// endpoint_changed identifies a confirmed URL-resolution mismatch;
// transport_configuration identifies configuration-read or resolution failures,
// including when the original remote name is absent.
type PublicationRecoveryError struct {
	Kind          string
	RecordPath    string   // selected or affected record path, when applicable.
	MissingFields []string // private-record field names required for the attempted classification.
	cause         error
}

// Error returns the credential-safe recovery diagnostic.
func (e *PublicationRecoveryError) Error() string {
	if e == nil {
		return ""
	}
	message := fmt.Sprintf("publication recovery %s", e.Kind)
	if e.RecordPath != "" {
		message += fmt.Sprintf(" for %q", git.DisplayDiagnostic(e.RecordPath))
	}
	if e.cause != nil {
		message += ": " + git.DisplayError(e.cause).Error()
	}
	return git.DisplayDiagnostic(message)
}

// Unwrap returns the underlying recovery or storage cause.
func (e *PublicationRecoveryError) Unwrap() error {
	if e == nil {
		return nil
	}
	return e.cause
}

// ReconcilePublication observes the recorded endpoint without running candidate
// validation or changing local or remote state.
func ReconcilePublication(ctx context.Context, evidence PublicationEvidence) (PublicationReconciliationResult, error) {
	observation, err := publish.Reconcile(ctx, internalEvidence(evidence))
	return publicObservation(observation), publicRecoveryError(err, "")
}

// LoadPublicationEvidence loads one explicit private attempt record. Relative
// paths are interpreted from the caller's current directory; no Git lookup is
// performed.
func LoadPublicationEvidence(path string) (PublicationEvidence, error) {
	evidence, err := publish.LoadEvidence(path)
	return publicEvidence(evidence), publicRecoveryError(err, path)
}

// PublicationAttemptsRequest selects local publication-attempt storage.
type PublicationAttemptsRequest struct {
	RepositoryDir string // repository used to resolve an empty or relative RecordDir; empty means the current directory.
	RecordDir     string // optional storage directory; relative paths use the repository root, and absolute paths can be listed outside a checkout.
}

// PublicationAttempt pairs one readable record path with the evidence it stores.
type PublicationAttempt struct {
	RecordPath string              // absolute path of the selected record.
	Evidence   PublicationEvidence // saved identity, including any partial fields.
}

// PublicationAttemptsResult contains readable attempts and per-record
// diagnostics from one local directory enumeration.
type PublicationAttemptsResult struct {
	RecordDir   string                      // resolved absolute directory selected for enumeration, when available.
	Attempts    []PublicationAttempt        // readable records in deterministic path order.
	Diagnostics []*PublicationRecoveryError // unreadable or unsupported records; other entries remain available.
}

// ListPublicationAttempts discovers saved local records without querying a
// remote or inferring which attempt should be reconciled.
func ListPublicationAttempts(ctx context.Context, request PublicationAttemptsRequest) (PublicationAttemptsResult, error) {
	listed, err := publish.ListAttempts(ctx, request.RepositoryDir, request.RecordDir)
	return publicAttemptsResult(listed, err)
}

func publicAttemptsResult(listed publish.AttemptsResult, err error) (PublicationAttemptsResult, error) {
	result := PublicationAttemptsResult{RecordDir: listed.RecordDir, Attempts: make([]PublicationAttempt, 0, len(listed.Attempts)), Diagnostics: make([]*PublicationRecoveryError, 0, len(listed.Diagnostics))}
	for _, attempt := range listed.Attempts {
		result.Attempts = append(result.Attempts, PublicationAttempt{RecordPath: attempt.RecordPath, Evidence: publicEvidence(attempt.Evidence)})
	}
	for _, diagnostic := range listed.Diagnostics {
		converted := publicRecoveryError(diagnostic, diagnostic.RecordPath)
		if recovery, ok := converted.(*PublicationRecoveryError); ok {
			result.Diagnostics = append(result.Diagnostics, recovery)
		}
	}
	return result, publicRecoveryError(err, "")
}

func internalEvidence(e PublicationEvidence) publish.Evidence { return publish.Evidence(e) }
func publicEvidence(e publish.Evidence) PublicationEvidence   { return PublicationEvidence(e) }
func publicObservation(o publish.Observation) PublicationReconciliationResult {
	return PublicationReconciliationResult{Evidence: publicEvidence(o.Evidence), State: PublicationState(o.State), ObservedTagObject: o.ObservedTagObject, ObservedCommit: o.ObservedCommit}
}

func publicRecoveryError(err error, path string) error {
	if err == nil {
		return nil
	}
	var recovery *publish.RecoveryError
	if errors.As(err, &recovery) {
		recordPath := path
		if recordPath == "" {
			recordPath = recovery.RecordPath
		}
		return &PublicationRecoveryError{Kind: recovery.Kind, RecordPath: recordPath, MissingFields: append([]string(nil), recovery.MissingFields...), cause: recovery}
	}
	return &PublicationRecoveryError{Kind: "remote_observation", RecordPath: path, cause: err}
}