// Package cli holds per-subcommand handlers. Each returns the process
// exit code (0=ok, 64=usage, 65=runtime error, 66=degraded — a
// degraded-mode run is NOT a hard failure but operators may want to
// gate CI on it).
package cli

import (
	"context"
	"encoding/json"
	"flag"
	"fmt"
	"os"
	"path/filepath"
	"time"

	"local-review-harness/internal/config"
	"local-review-harness/internal/llm"
)

// commonFlags wires the three flags every subcommand accepts.
type commonFlags struct {
	reviewProfilePath string
	modelProfilePath  string
	outputDir         string
}

func bindCommonFlags(fs *flag.FlagSet, cf *commonFlags) {
	fs.StringVar(&cf.reviewProfilePath, "review-profile", "", "review profile YAML (defaults applied if empty)")
	fs.StringVar(&cf.modelProfilePath, "model-profile", "", "model profile YAML (defaults applied if empty)")
	fs.StringVar(&cf.outputDir, "output-dir", "", "override review profile output dir")
}

// resolveOutputDir picks the output dir from flag > review profile >
// hardcoded fallback. Always relative to the target repo, NOT the
// harness's own cwd — operators pointing at a remote checkout want
// reports landing inside that checkout.
func resolveOutputDir(cf *commonFlags, rp config.ReviewProfile, repoPath string) string {
	dir := cf.outputDir
	if dir == "" {
		dir = rp.Reports.OutputDir
	}
	if dir == "" {
		dir = "reports/latest"
	}
	if filepath.IsAbs(dir) {
		return dir
	}
	return filepath.Join(repoPath, dir)
}

// writeJSON marshals v to path with indent, creating the dir.
func writeJSON(path string, v any) error {
	if err := os.MkdirAll(filepath.Dir(path), 0o755); err != nil {
		return err
	}
	bs, err := json.MarshalIndent(v, "", "  ")
	if err != nil {
		return err
	}
	bs = append(bs, '\n')
	return os.WriteFile(path, bs, 0o644)
}

// nowUTC returns ISO-8601 UTC for receipt timestamps.
func nowUTC() string { return time.Now().UTC().Format(time.RFC3339Nano) }

// Stub-only sentinel — Phase C replaces this with real Ollama provider.
// Phase A keeps the pipeline runnable end-to-end with a degraded-status
// model-doctor JSON.
func nilProvider() llm.Provider { return nil }

// Repo runs Phase 0 (intake) + Phase 1 (static scan) + Phase 4
// (report gen). Phase B implements the analyzers + scanner; Phase
// A leaves repoCmd as a stub until B lands.
func Repo(args []string) int {
	fs := flag.NewFlagSet("repo", flag.ContinueOnError)
	var cf commonFlags
	bindCommonFlags(fs, &cf)
	if err := fs.Parse(args); err != nil {
		return 64
	}
	if fs.NArg() < 1 {
		fmt.Fprintln(os.Stderr, "repo: missing target path")
		return 64
	}
	repoPath := fs.Arg(0)
	return runRepo(context.Background(), repoPath, cf)
}

// Scrum runs the same pipeline as Repo but emits the full Scrum
// report bundle. In Phase B both subcommands share the pipeline;
// scrum just toggles the markdown report set on.
func Scrum(args []string) int {
	fs := flag.NewFlagSet("scrum", flag.ContinueOnError)
	var cf commonFlags
	bindCommonFlags(fs, &cf)
	if err := fs.Parse(args); err != nil {
		return 64
	}
	if fs.NArg() < 1 {
		fmt.Fprintln(os.Stderr, "scrum: missing target path")
		return 64
	}
	repoPath := fs.Arg(0)
	return runScrum(context.Background(), repoPath, cf)
}

// ModelDoctor probes the configured model provider and writes
// reports/latest/model-doctor.json. Phase A returns degraded status
// (no real probe yet); Phase C wires the Ollama HealthCheck call.
func ModelDoctor(args []string) int {
	fs := flag.NewFlagSet("model doctor", flag.ContinueOnError)
	var cf commonFlags
	bindCommonFlags(fs, &cf)
	if err := fs.Parse(args); err != nil {
		return 64
	}

	rp, err := config.LoadReviewProfile(cf.reviewProfilePath)
	if err != nil {
		fmt.Fprintln(os.Stderr, "config:", err)
		return 65
	}
	mp, err := config.LoadModelProfile(cf.modelProfilePath)
	if err != nil {
		fmt.Fprintln(os.Stderr, "config:", err)
		return 65
	}

	// Output dir is local cwd for `model doctor` since it's not
	// repo-bound (no positional path argument).
	outDir := cf.outputDir
	if outDir == "" {
		outDir = rp.Reports.OutputDir
	}

	// Phase A: stub. Phase C swaps in a real probe.
	doc := map[string]any{
		"provider":                 mp.Provider,
		"base_url":                 mp.BaseURL,
		"primary_model":            mp.Model,
		"fallback_model":           mp.FallbackModel,
		"server_available":         false,
		"primary_model_available":  false,
		"fallback_model_available": false,
		"basic_prompt_ok":          false,
		"json_mode_ok":             false,
		"timeout_seconds":          mp.TimeoutSeconds,
		"status":                   "degraded",
		"errors":                   []string{"phase A stub: real Ollama probe lands in Phase C"},
		"generated_at":             nowUTC(),
	}
	out := filepath.Join(outDir, "model-doctor.json")
	if err := writeJSON(out, doc); err != nil {
		fmt.Fprintln(os.Stderr, "write:", err)
		return 65
	}
	fmt.Println(out)
	return 66 // degraded exit code
}