package control

import (
	"encoding/json"
	"errors"
	"fmt"
	"io"
	"regexp"
	"strconv"
	"strings"

	"gitbay.org/gitbay/internal/ci"
	"gitbay.org/gitbay/internal/gitutil"
	"gitbay.org/gitbay/internal/policy"
	"gitbay.org/gitbay/internal/protocol"
	"gitbay.org/gitbay/internal/store"
)

func init() {
	register(Command{Path: []string{"build", "list"},
		Summary: "list recent builds: build list <owner/name>", ReadOnly: true, Run: runBuildList})
	register(Command{Path: []string{"build", "show"},
		Summary: "show one build: build show <owner/name> <n>", ReadOnly: true, Run: runBuildShow})
	register(Command{Path: []string{"build", "log"},
		Summary: "print a build's log: build log <owner/name> <n>", ReadOnly: true, Run: runBuildLog})

	register(Command{Path: []string{"build", "trigger"},
		Summary: "queue a job now (scheduled or not): build trigger <owner/name> <job>", Run: runBuildTrigger})
	// Secrets: set over stdin, listed by name only, injected into the
	// repo's builds as environment variables. Same discipline as mirror
	// tokens — the value never appears in argv, logs, or output.
	register(Command{Path: []string{"repo", "secret", "set"},
		Summary:    "set a build secret: repo secret set <owner/name> <NAME> (value on stdin)",
		ReadsStdin: true, SSHOnly: true, Run: runSecretSet})
	register(Command{Path: []string{"repo", "secret", "remove"},
		Summary: "remove a build secret: repo secret remove <owner/name> <NAME>", Run: runSecretRemove})
	register(Command{Path: []string{"repo", "secret", "list"},
		Summary: "list build secret names: repo secret list <owner/name>", ReadOnly: true, Run: runSecretList})

	// Runner commands: the claim/report loop for gitbay-runner. Admin-only —
	// a runner executes arbitrary repo code, so handing out jobs is the
	// instance operator's call.
	register(Command{Path: []string{"runner", "next"},
		Summary: "claim the oldest pending build (runner protocol)", SSHOnly: true, Run: runRunnerNext})
	register(Command{Path: []string{"runner", "log"},
		Summary: "append a build's log from stdin: runner log <build-id>", SSHOnly: true, ReadsStdin: true, Run: runRunnerLog})
	register(Command{Path: []string{"runner", "done"},
		Summary: "finish a build: runner done <build-id> success|failure", SSHOnly: true, Run: runRunnerDone})
}

type buildOut struct {
	Number     int64  `json:"number"`
	Job        string `json:"job"`
	Status     string `json:"status"`
	SHA        string `json:"sha"`
	Ref        string `json:"ref"`
	CreatedAt  string `json:"created_at"`
	FinishedAt string `json:"finished_at,omitempty"`
}

func buildToOut(b store.Build) buildOut {
	return buildOut{b.Number, b.Job, b.Status, b.SHA, b.Ref, b.CreatedAt, b.FinishedAt}
}

func buildRef(c *Ctx, args []string) (store.Repo, store.Build, int) {
	if len(args) != 2 {
		return store.Repo{}, store.Build{}, c.fail(protocol.ExitUsage, "expected <owner/name> <number>")
	}
	repo, code := resolveRepo(c, args[0], policy.CanRead)
	if code >= 0 {
		return repo, store.Build{}, code
	}
	n, err := strconv.ParseInt(args[1], 10, 64)
	if err != nil {
		return repo, store.Build{}, c.fail(protocol.ExitUsage, "bad build number %q", args[1])
	}
	b, err := c.Store.BuildByNumber(repo.ID, n)
	if err != nil {
		return repo, b, c.fail(protocol.ExitNotFound, "no build %d on %s", n, repo.Path())
	}
	return repo, b, -1
}

func runBuildList(c *Ctx, args []string) int {
	if len(args) != 1 {
		return c.fail(protocol.ExitUsage, "usage: build list <owner/name>")
	}
	repo, code := resolveRepo(c, args[0], policy.CanRead)
	if code >= 0 {
		return code
	}
	builds, err := c.Store.ListBuilds(repo.ID, 50)
	if err != nil {
		return c.fail(protocol.ExitFailure, "%v", err)
	}
	var ds []buildOut
	for _, b := range builds {
		ds = append(ds, buildToOut(b))
	}
	return c.emit(ds, func(w io.Writer) {
		for _, d := range ds {
			fmt.Fprintf(w, "%d\t%s\t%s\t%.10s\t%s\n", d.Number, d.Job, d.Status, d.SHA, d.Ref)
		}
	})
}

func runBuildShow(c *Ctx, args []string) int {
	_, b, code := buildRef(c, args)
	if code >= 0 {
		return code
	}
	d := buildToOut(b)
	return c.emit(d, func(w io.Writer) {
		fmt.Fprintf(w, "build %d\t%s\t%s\n%.10s on %s\nqueued %s", d.Number, d.Job, d.Status, d.SHA, d.Ref, d.CreatedAt)
		if d.FinishedAt != "" {
			fmt.Fprintf(w, ", finished %s", d.FinishedAt)
		}
		fmt.Fprintln(w)
	})
}

func runBuildLog(c *Ctx, args []string) int {
	_, b, code := buildRef(c, args)
	if code >= 0 {
		return code
	}
	log, err := c.Store.BuildLog(b.ID)
	if err != nil {
		return c.fail(protocol.ExitFailure, "%v", err)
	}
	c.Stdout.Write(log)
	return protocol.ExitOK
}

func runBuildTrigger(c *Ctx, args []string) int {
	if len(args) != 2 {
		return c.fail(protocol.ExitUsage, "usage: build trigger <owner/name> <job>")
	}
	repo, code := resolveRepo(c, args[0], policy.CanWrite)
	if code >= 0 {
		return code
	}
	dir := RepoDir(c.Cfg.Server.Root, repo.OwnerName, repo.Name)
	sha, err := gitutil.ResolveRef(dir, "refs/heads/"+repo.DefaultBranch)
	if err != nil {
		return c.fail(protocol.ExitFailure, "resolving %s: %v", repo.DefaultBranch, err)
	}
	raw, err := gitutil.ReadBlob(dir, sha, ci.ConfigPath, 1<<16)
	if err != nil {
		return c.fail(protocol.ExitNotFound, "%s has no %s on %s", repo.Path(), ci.ConfigPath, repo.DefaultBranch)
	}
	jobs, err := ci.Parse(raw)
	if err != nil {
		return c.fail(protocol.ExitUsage, "%v", err)
	}
	for _, j := range jobs {
		if j.Name != args[1] {
			continue
		}
		steps, _ := json.Marshal(j.Steps)
		n, err := c.Store.CreateBuild(repo.ID, j.Name, sha, repo.DefaultBranch, string(steps))
		if err != nil {
			return c.fail(protocol.ExitFailure, "%v", err)
		}
		url := fmt.Sprintf("%s/%s/builds/%d", c.Cfg.Server.SiteURL, repo.Path(), n)
		c.Store.SetCommitStatus(repo.ID, sha, "ci/"+j.Name, "pending", "triggered", url, c.User.ID)
		return c.emit(map[string]any{"build": n, "job": j.Name, "sha": sha}, func(w io.Writer) {
			fmt.Fprintf(w, "queued build %d (%s @ %.10s)\n", n, j.Name, sha)
		})
	}
	return c.fail(protocol.ExitNotFound, "no job %q in %s", args[1], ci.ConfigPath)
}

// secretName is env-var shaped: the value lands in the build environment.
var secretName = regexp.MustCompile(`^[A-Z_][A-Z0-9_]{0,63}$`)

func runSecretSet(c *Ctx, args []string) int {
	if len(args) != 2 {
		return c.fail(protocol.ExitUsage, "usage: repo secret set <owner/name> <NAME> (value on stdin)")
	}
	if !secretName.MatchString(args[1]) {
		return c.fail(protocol.ExitUsage, "secret names are env-var shaped: uppercase letters, digits, _")
	}
	repo, code := resolveRepo(c, args[0], policy.CanAdmin)
	if code >= 0 {
		return code
	}
	raw, err := io.ReadAll(io.LimitReader(c.Stdin, 64<<10))
	if err != nil {
		return c.fail(protocol.ExitFailure, "reading secret: %v", err)
	}
	value := strings.TrimRight(string(raw), "\n")
	if value == "" {
		return c.fail(protocol.ExitUsage, "no value on stdin (pipe it: printf %%s TOKEN | ...)")
	}
	if err := c.Store.SetBuildSecret(repo.ID, args[1], value); err != nil {
		return c.fail(protocol.ExitFailure, "%v", err)
	}
	return c.emit(map[string]string{"secret": args[1]}, func(w io.Writer) {
		fmt.Fprintf(w, "secret %s set on %s\n", args[1], repo.Path())
	})
}

func runSecretRemove(c *Ctx, args []string) int {
	if len(args) != 2 {
		return c.fail(protocol.ExitUsage, "usage: repo secret remove <owner/name> <NAME>")
	}
	repo, code := resolveRepo(c, args[0], policy.CanAdmin)
	if code >= 0 {
		return code
	}
	if err := c.Store.RemoveBuildSecret(repo.ID, args[1]); err != nil {
		if errors.Is(err, store.ErrNotFound) {
			return c.fail(protocol.ExitNotFound, "no secret %s on %s", args[1], repo.Path())
		}
		return c.fail(protocol.ExitFailure, "%v", err)
	}
	return c.emit(map[string]string{"removed": args[1]}, func(w io.Writer) {
		fmt.Fprintf(w, "removed %s\n", args[1])
	})
}

func runSecretList(c *Ctx, args []string) int {
	if len(args) != 1 {
		return c.fail(protocol.ExitUsage, "usage: repo secret list <owner/name>")
	}
	repo, code := resolveRepo(c, args[0], policy.CanAdmin)
	if code >= 0 {
		return code
	}
	names, err := c.Store.ListBuildSecretNames(repo.ID)
	if err != nil {
		return c.fail(protocol.ExitFailure, "%v", err)
	}
	return c.emit(names, func(w io.Writer) {
		for _, n := range names {
			fmt.Fprintln(w, n)
		}
	})
}

func requireRunner(c *Ctx) int {
	if !c.User.IsAdmin {
		return c.fail(protocol.ExitDenied, "runner commands are for instance-admin runner accounts")
	}
	return -1
}

func runRunnerNext(c *Ctx, args []string) int {
	if code := requireRunner(c); code >= 0 {
		return code
	}
	b, ok, err := c.Store.ClaimBuild()
	if err != nil {
		return c.fail(protocol.ExitFailure, "%v", err)
	}
	if !ok {
		return c.emit(map[string]any{}, func(w io.Writer) { fmt.Fprintln(w, "no pending builds") })
	}
	repo, err := c.Store.RepoByID(b.RepoID)
	if err != nil {
		return c.fail(protocol.ExitFailure, "%v", err)
	}
	var steps []string
	json.Unmarshal([]byte(b.Steps), &steps)
	// Secrets ride the claim: this channel is admin-only and the values
	// land in the build's environment, nowhere else.
	secrets, err := c.Store.BuildSecrets(b.RepoID)
	if err != nil {
		return c.fail(protocol.ExitFailure, "%v", err)
	}
	d := struct {
		ID      int64             `json:"id"`
		Repo    string            `json:"repo"`
		Number  int64             `json:"number"`
		Job     string            `json:"job"`
		SHA     string            `json:"sha"`
		Ref     string            `json:"ref"`
		Steps   []string          `json:"steps"`
		Secrets map[string]string `json:"secrets,omitempty"`
	}{b.ID, repo.Path(), b.Number, b.Job, b.SHA, b.Ref, steps, secrets}
	return c.emit(d, func(w io.Writer) {
		fmt.Fprintf(w, "build %d: %s %s @ %.10s\n", d.ID, d.Repo, d.Job, d.SHA)
	})
}

func runRunnerLog(c *Ctx, args []string) int {
	if code := requireRunner(c); code >= 0 {
		return code
	}
	if len(args) != 1 {
		return c.fail(protocol.ExitUsage, "usage: runner log <build-id> (chunk on stdin)")
	}
	id, err := strconv.ParseInt(args[0], 10, 64)
	if err != nil {
		return c.fail(protocol.ExitUsage, "bad build id %q", args[0])
	}
	// Stream stdin into the log in chunks so long builds appear live.
	buf := make([]byte, 64<<10)
	for {
		n, rerr := c.Stdin.Read(buf)
		if n > 0 {
			if err := c.Store.AppendBuildLog(id, buf[:n]); err != nil {
				return c.fail(protocol.ExitFailure, "%v", err)
			}
		}
		if rerr != nil {
			break
		}
	}
	return c.emit(map[string]string{"log": "ok"}, func(w io.Writer) {})
}

func runRunnerDone(c *Ctx, args []string) int {
	if code := requireRunner(c); code >= 0 {
		return code
	}
	if len(args) != 2 || (args[1] != "success" && args[1] != "failure") {
		return c.fail(protocol.ExitUsage, "usage: runner done <build-id> success|failure")
	}
	id, err := strconv.ParseInt(args[0], 10, 64)
	if err != nil {
		return c.fail(protocol.ExitUsage, "bad build id %q", args[0])
	}
	b, err := c.Store.BuildByID(id)
	if err != nil {
		return c.fail(protocol.ExitNotFound, "no build %d", id)
	}
	if err := c.Store.FinishBuild(id, args[1]); err != nil {
		return c.fail(protocol.ExitFailure, "finishing build %d: %v", id, err)
	}
	repo, err := c.Store.RepoByID(b.RepoID)
	if err != nil {
		return c.fail(protocol.ExitFailure, "%v", err)
	}
	url := fmt.Sprintf("%s/%s/builds/%d", c.Cfg.Server.SiteURL, repo.Path(), b.Number)
	desc := "build " + args[1]
	if err := c.Store.SetCommitStatus(repo.ID, b.SHA, "ci/"+b.Job, args[1], desc, url, c.User.ID); err != nil {
		return c.fail(protocol.ExitFailure, "%v", err)
	}
	c.Store.RecordEvent(repo.ID, c.User.ID, "build."+args[1],
		fmt.Sprintf(`{"number":%d,"job":%q}`, b.Number, b.Job))
	return c.emit(map[string]any{"build": b.Number, "status": args[1]}, func(w io.Writer) {
		fmt.Fprintf(w, "build %d %s\n", b.Number, args[1])
	})
}