package app

import (
	"context"
	"flag"
	"fmt"
	"io"
	"sort"
	"strings"

	"gitea.maximumdirect.net/eric/narratio/internal/adapters/storage"
	"gitea.maximumdirect.net/eric/narratio/internal/artifacts"
	"gitea.maximumdirect.net/eric/narratio/internal/config"
)

// Status reports effective local/remote session state.
func Status(ctx context.Context, args []string, out io.Writer) error {
	fs := flag.NewFlagSet("status", flag.ContinueOnError)
	fs.SetOutput(io.Discard)
	var flags commonConfigFlags
	addCommonConfigFlags(fs, &flags)
	if err := parseSessionAwareFlags("status", fs, args, &flags.sessionID); err != nil {
		return err
	}
	if strings.TrimSpace(flags.sessionID) == "" {
		return fmt.Errorf("status: session_id is required")
	}
	cfg, err := loadCommandConfig(ctx, flags.pipelinePath, flags.campaignPath, flags.campaignFilePath, flags.sessionPath, flags.sessionOptions())
	if err != nil {
		return fmt.Errorf("status: %w", err)
	}
	if err := config.Validate(cfg); err != nil {
		return fmt.Errorf("status: %w", err)
	}
	paths := artifacts.NewLocalStore(cfg.Pipeline.Workspace.Root).SessionPathsFor(cfg.Session.Campaign, cfg.Session.SessionID)
	fmt.Fprintf(out, "Session: %s\n", cfg.Session.SessionID)
	fmt.Fprintf(out, "Campaign: %s\n", cfg.Session.Campaign)
	fmt.Fprintf(out, "Workspace: %s\n", paths.Root)
	fmt.Fprintf(out, "Session config: %s\n", sessionSourceSummary(cfg))
	writeStatusStableInputs(out, inspectStableInputs(cfg))
	writeStatusLocalAudio(out, inspectLocalAudioPresence(cfg))

	if m, err := loadLocalManifest(ctx, paths.ManifestPath); err != nil {
		fmt.Fprintf(out, "Local manifest: error: %v\n", err)
	} else if m == nil {
		fmt.Fprintln(out, "Local manifest: missing")
	} else {
		fmt.Fprintf(out, "Local manifest: %s\n", paths.ManifestPath)
		writeStageStatuses(out, m)
	}

	store, storeErr := objectStoreIfConfigured(ctx, cfg)
	if storeErr != nil {
		fmt.Fprintf(out, "Remote publish: unavailable: %v\n", storeErr)
	} else if store != nil {
		current := inspectRemoteCurrentState(ctx, cfg, store)
		if current.Err != nil {
			fmt.Fprintf(out, "Remote publish: missing or unavailable: %v\n", current.Err)
		} else {
			fmt.Fprintf(out, "Remote publish: current run %s\n", current.State.RunID)
			fmt.Fprintf(out, "Remote manifest: %s\n", current.State.CurrentManifestKey)
		}
	}
	writeStatusRemoteAudio(ctx, out, cfg, store, storeErr)
	writeStatusPreviousArtifacts(out, inspectPreviousArtifactReadiness(
		ctx,
		cfg,
		store,
		artifacts.CollectPreviousArtifactRequirements(configuredScriptoriumArtifacts(cfg)),
	))

	lockChecks := inspectEffectiveLocks(ctx, cfg, store)
	locks := lockChecks.Locks
	lockErr := lockChecks.Err
	if catalog, catalogErr := buildHelperArtifactCatalog(cfg); catalogErr != nil {
		fmt.Fprintf(out, "Remote outputs: error: %v\n", catalogErr)
	} else if storeErr == nil {
		catalogLocks := locks
		if lockErr != nil {
			catalogLocks = &effectiveLocks{
				Static: staticPublishLocks(cfg),
				All:    staticPublishLocks(cfg),
			}
		}
		publishedRemoteState := map[string]string{}
		if store != nil {
			publishedRemoteState = remotePublishedOutputAvailability(ctx, cfg, store, catalog)
		}
		fmt.Fprintln(out, "Remote outputs:")
		writeArtifactList(out, cfg, catalog, catalogLocks, publishedRemoteState)
	}
	if lockErr != nil {
		fmt.Fprintf(out, "Publish locks: error: %v\n", lockErr)
	} else {
		writeLocks(out, cfg, locks)
	}
	fmt.Fprintln(out, "Next actions:")
	fmt.Fprintf(out, "- narratio session validate %s\n", cfg.Session.SessionID)
	fmt.Fprintf(out, "- narratio session restore %s --dry-run\n", cfg.Session.SessionID)
	return nil
}

func writeStatusStableInputs(out io.Writer, checks []stableInputCheck) {
	if len(checks) == 0 {
		return
	}
	for _, check := range checks {
		if check.Err != nil {
			if strings.TrimSpace(check.Path) != "" {
				fmt.Fprintf(out, "Stable input %s: unavailable: %v\n", check.Name, check.Err)
			} else {
				fmt.Fprintf(out, "Stable input %s: unavailable: %s\n", check.Name, check.Err.Error())
			}
			continue
		}
		fmt.Fprintf(out, "Stable input %s: %s\n", check.Name, check.Path)
	}
}

func writeStatusLocalAudio(out io.Writer, check localAudioCheck) {
	if !check.Checked {
		return
	}
	if check.Err != nil {
		fmt.Fprintf(out, "Local audio: unavailable: %v\n", check.Err)
		return
	}
	fmt.Fprintf(out, "Local audio: %d file(s)\n", len(check.Paths))
}

func writeStatusRemoteAudio(ctx context.Context, out io.Writer, cfg *config.Config, store storage.ObjectStore, storeErr error) {
	if cfg.Session.Inputs.AudioS3 == nil {
		return
	}
	if storeErr != nil {
		fmt.Fprintf(out, "Remote audio: unavailable: %v\n", storeErr)
		return
	}
	check := inspectRemoteAudioPresence(ctx, cfg, store)
	if check.Err != nil {
		fmt.Fprintf(out, "Remote audio: unavailable: %v\n", check.Err)
		return
	}
	fmt.Fprintf(out, "Remote audio: %d .flac object(s)\n", len(check.Keys))
}

func writeStatusPreviousArtifacts(out io.Writer, readiness previousArtifactReadiness) {
	if len(readiness.Requirements) == 0 {
		fmt.Fprintln(out, "Previous-session artifacts: not required")
		return
	}
	if readiness.MissingID {
		fmt.Fprintln(out, "Previous-session artifacts: unavailable: previous_session_id is required by configured previous-session artifacts")
		return
	}
	if readiness.Err != nil {
		fmt.Fprintf(out, "Previous-session artifacts: unavailable: %v\n", readiness.Err)
		return
	}
	names := make([]string, 0, len(readiness.Requirements))
	for _, req := range readiness.Requirements {
		names = append(names, fmt.Sprintf("%s(required=%t)", req.Name, req.Required))
	}
	sort.Strings(names)
	fmt.Fprintf(out, "Previous-session artifacts: ready: %s\n", strings.Join(names, ", "))
}